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1 of 8 24/03/2007 9:15 AM

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Foundation Repair InformationInformaton | Maintenance | Underpinning

Foundation Maintenance

By: W. Tom Witherspoon, P.E.

|| Slope Maintenance || Earth Perimeters || Flat Work || Flower Beds ||

|| Gutters And Downspouts || Sub-Surface Drains || Capillary/French Drains ||

|| Irrigation/Sprinkler Systems || Vegetation And Trees || Plumbing Leaks ||

|| Reinforcing Steel Exposure || Brick, Rock Or Cladding Cracks || Vent Covers ||

|| Animal Damage || Termite Damage || Interior Doors ||

A study of failed foundations (ADSC 2000) estimates the cost of foundation repair at over 12.5 billion

dollars annually. The most common cause of foundation failure/problems is poor maintenance, which can

normally be prevented. Considering that most remedial action will not completely keep a foundation from

moving, it becomes even more important that the homeowner complies with the required maintenance .

procedures to reduce movement and allow the house to function as originally intended. This is just as

important after repairs have been complete because the house may move in an area that has not been

repaired or is still dependent upon bearing soil stability for continued performance. Since many

foundation repair companies require homeowner maintenance as a condition of their warranty agreement,

compliance is also good business and one of the best insurance policies available.

The following categories of maintenance are the most common problem areas and should be addressed in

a scheduled sequence to reduce movement before and after foundation repairs to minimize distress in the

foundation and the structure it supports.

Slope Maintenance

The foundation should have been installed sufficiently above site grades to allow proper post-construction

surface drainage. It is the homeowner's responsibility, however, to maintain these positive drainage

conditions. The primary function of good drainage is to prevent ponding near, or intrusion of water, under

the structure, which would increase seasonal moisture fluctuations, or migration of water. Much of the

damage caused by expansive soils is due to lack of timely maintenance by the homeowner and is in some

part preventable.

Under ideal conditions the slab will maintain its original position. Unfortunately soil is not consistent and

the moisture content is seldom at an optimum level in the support soil when the slab is constructed. Many

slabs are poured on drier than normal soil that later becomes wet from capillary rise of water from below,

causing the thin floors to lift. After repeated drying and rewetting of the support soil, small amounts of

soil are squeezed from the interface of the concrete base and the soil base to lower the wall into the

ground, much like a car tire miring into a rut. If the soil has a high amount of clay content, it will also

deform under pressure, much like children's putty during the swelling stage.

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Earth Perimeters

The excavated area outside the foundation is usually filled with loose soil fill when a house is constructed.


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This is usually called the "backfill area". Maintaining a positive slope in the backfill area next to the house

is the most critical aspect of slope maintenance. During the first few months or years, this material often

settles. In many cases settlement is severe enough to reverse or flatten the slope next to the foundation.

Reverse or negative drainage will cause ponding of water during precipitation or heavy irrigation.

Ponding allows an excessive amount of water to percolate into the ground" next to the foundation, which

may accelerate this settlement. To avoid this, the homeowner should periodically compact the backfill

area by tamping with a heavy piece of wood such as a 4 "x4 " . Hand compaction works best after a rain

or snow melt has dampened the ground or with the careful addition of small amounts of water by the

homeowner such as with a drip line. Additional soil should be added as necessary to maintain a positive

slope away from the foundation. This soil should always be clay, not sand, so moisture can be better

maintained and water will run off instead of soaking in spotty high concentrations.

Rhe minimum slope requirement should be 5% for the first 5' away from the foundation (3" of drop) and

then at a minimum discharge slope of 1% (approximately 1/8" drop for every foot of distance) from that

point on. The type of vegetation may dictate a greater slope to avoid over saturation of the critical

perimeter soil. Some type of ground cover is recommended, however, to reduce erosion and lower the

frequency of slope maintenance work.

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Flat Work

One of the beneficial functions of flat work {sidewalks and patios that are not part of the foundation)

adjacent to foundations is the prevention of evapotranspiration and fluctuation of water intrusion to the

bearing soils. Therefore, every homeowner should conduct a yearly inspection of concrete flat work and

do any maintenance necessary to improve drainage and minimize infiltration of water from rain, snow

melt and lawn watering. This is especially important during the first five years for a newly built house

because this is usually the time of most severe a9justment between the new construction and environment.

The process of inspection and maintenance should continue over the years, but, cracking, settling and

other problems should become less common.

Because perimeter fill material may not have been compacted in 4" lifts at optimum moisture (as is

normally recommended by engineers), settlement is greater along the house. A negative slope may occur

that will allow ponding. This concentration of water wiII allow permeation through cracks in the concrete

and over- saturation of perimeter bearing soils. This deeper saturation will often times cause damage to

the foundation and/or basement floors. Because evaporation is limited by the flat work, the ponded water

may dramatically increase moisture levels at the crucial perimeter beams and/or piers.

When this tilting of flat work occurs, the concrete should be replaced or mudjacked to reverse the

negative slope. If a minimum of 1 % slope (again about 1/8" for every foot of distance) is maintained,

however, it will only be necessary to seal all cracks and ports of entry to prevent vertical water migration.

This will include the perimeter joint around the foundation grade beam. A urethane or other flexible

sealant should be used that will allow some movement but prevent water passing below the slab.

|| Top of Page ||

Flower Beds

Changing the site by the addition of flower beds, patios, fences,

swimming pools, etc., may cause water ponding, which will exacerbate

the wet cycles. Therefore, proper drainage considerations during such

additions must be made.

Nurserymen will specify peat, bark, sandy loam and other planting

substances, which, in conjunction with bed borders, will increase moisture

levels above that desirable. Therefore, flower beds must have some

provisions for elimination of excess water. This may be in the form of

weep holes, drain barriers or other removal systems. The problems

created by flower beds are not a popular subject since homeowners will

resist good engineering to beautify their house. There should be a balance

between vegetation utilized for aesthetic demands and harming the


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bearing soils.

One of the primary problems in flower bed design is installation of a

concrete or steel barrier that will resist normalwater run-off. If these

barriers are desired, they should have openings cut to allow water passage

and avoid over-saturation.

The use of highly permeable materials

such as peat, bark, etc., should only be

used if topography allows installation of

subsurface drainage to collect excess

water and discharge it away from the

foundation. This will also require

installation of an impermeable barrier at

the bottom of the flower bed to help collect water for removal by the drain

medium.

Shrubs planted in the flower bed should be chosen for their compatibility

to the shallow barrier of the bed. Short and very contained root growth

will be a plus to proper health and maintenance of the bed vegetation.

In the flower bed, the slope should be a minimum of 5% (5/8" for every foot of distance), unless ample

subsurface drainage can be created to discharge water away from the foundation.

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Gutters And Downspouts

Gutters should be inspected twice a year,

once in the spring and again in the fall. All

debris should be cleaned out and metal

gutters checked for rust. If there are trees near

the roof, gutters may have to be cleaned out

more often.

Check the slope of the gutters, since poor

slope causes water to accumulate in low

spots, building up debris and accelerating

rusting. Slope of the gutters should be a

minimum of 1" of fall for each eight feet of

length. The gutter can be installed so that it

drains in one direction. If, however, any

single length of gutter is more than 35' long it

should be installed to drain both ways from

the center or have downspouts at a spacing of

not more than 20' on center.

The easiest way to check the slope of a gutter

is to use a garden hose or pour a bucket of

water into it and see if the water flows out

smoothly or ponds in low spots. The gutter should then be adjusted to remove any high or low spots that

prevent the smooth flow of water.

Downspouts should be checked for clogging at the same time the gutters are checked. Clogging often

occurs at the elbow where downspout and gutter meet. The elbow can be removed for cleaning, but it may

be necessary to use a plumber's snake to clean the downspout. If there is a problem with leaves, a leaf

strainer or leaf guard is a good buy as long as neither prevents proper function of the gutter.

Splash blocks should be long enough and sloped enough to carryall water well away from the foundation

and beyond the backfill area. Water should be discharged no closer than 5' from the foundation. Usually it

is necessary to add a downspout extension in order to get the water far away from the foundation. It is

possible to purchase extensions that have flexible elbows that can be bent up to make it easier to mow the

lawn. The extensions should be left down at all times. Special roll-up type downspout sheets (plastic


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tubes) that attach to the end of the downspout are also available. These plastic tubes extend when filled

with water and roll up when empty. If erosion is a possibility, splash blocks can be placed at the discharge

point to prevent associated problems.

Because the materials delineated above are readily accessible at most hardware and do-it- yourself stores

in a variety of makes and colors, they can add to the aesthetic qualities of a house.

|| Top of Page ||

Sub-Surface Drains

Subsurface drains will many times be utilized when topography, vegetation or construction does not make

it possible to drain at the surface. These may consist of drain inlet basins, trench drains, funnel drains, etc.

If correctly installed, subsurface drains should require little maintenance. The most important thing to

remember is to avoid covering or obstructing the drain where it discharges and to maintain adequate

slope. It may occasionally be necessary to clean out roots, nests or other debris from inlet basins or

discharging ends of the pipe.

Inlet basins should be inspected every 6 months to ensure these do not become clogged with leaves, grass,

soil or other debris, which would negate function. The bottom of these inlets normally has a sedimentation

basin that requires removal of dirt as fill adds up over time. It may also be necessary to back wash (main

lines when discharge becomes a noticeable problem. If problems persist, running of a( mechanical snake

may be necessary to remove 1 the obstruction.

Settlement problems in a yard will many I times crush piping and reduce the discharge I flow, which will

cause sedimentation to occur and subsequent closure of the drain lines. Damage may also result from the

driving of heavy trucks across the surface. In any case, repair will normally require excavation and

replacement of the drain line. This may be an even greater possibility if clay tile is used in lieu of heavy

duty pvc.

Location of clean-outs and discharge lines will be a plus to locate problems and initiate corrective action.

Therefore, a drawing of lines and locations should be made during installation for future reference.

|| Top of Page ||

Capillary/French Drains

Capillary drains are installed to intercept and collect moving subsurface

water and discharge it away from the structure. Unless the slope allows,

this will many times require installation of a deep sump and pump to

collect water and discharge it through a shallow drain line.

The pumps utilized in this operation may

malfunction and unless an alarm system is


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installed there will be no warning.

Therefore, it is advisable that the

homeowner inspect the sump at least

every 6 months to make sure trash, debris

or pump failure has not occurred. If a solid sump well cover is used, there

will be less potential for debris, but the homeowner will not be able to

view the sump and determine if it is functioning. Therefore, the addition

of an alarm is recommended to provide a warning to the homeowner prior

to the onset of other problems, such as upheaval or water intrusion into

the structure.

Discharge lines should have clean-outs to allow removal of obstructions

by use of a snake or by jetting. Because effectiveness of these systems is

largely unknown until problems occur, it is wise to also backwash the system from the discharge end

and/or at the sump at lease every 2 years. The effectiveness of this backwash will normally be seen by a

discharge of debris, which may have clogged the system.

Capillary drains are many times utilized as moisture barriers along the perimeter of a foundation to shed

water and stabilize sub slab moisture. This will include extension of an impermeable barrier drain material

under flower pipe beds and up along French Drain grade beams. Therefore, it is important for the home-

owner to avoid any planting action that may puncture the barrier material. If this damage occurs, it will be

necessary to patch the hole with materials that maintain the integrity of the barrier.

|| Top of Page ||

Irrigation/Sprinkler Systems

Watering of lawns and house perimeters must be regulated to maintain consistent moisture content under

the foundation. Therefore, allowances for shrubs, plants and trees must be regulated for each segment of

the yard. It is advisable that watering along foundation perimeters should be on a maintenance basis in

corroboration with seasonal needs. This should be in conjunction with plant and tree requirements so that

added water will not be siphoned from under the foundation.

Seasonal monitoring will necessitate different watering for the

sides that receive added and hotter sunlight (south and west

sides), which increases evaporation. This monitoring will also

take into consideration time of day for watering. Most

authorities recommend early morning watering so that less

evaporation will occur.

It must be understood that over watering can be just as damaging

to the foundation as under watering. If an electronic sprinkler

system is installed, each of the factors listed above must be

incorporated into the sequence and timing. Visual observations

must also be included in the process to make adjustments

beyond the capacity of normal programming.

A variety of watering heads and systems are on the market that can be customized to a homeowner's

needs. There are bubble sprays, side sprays or angle sprays that discharge from riser heads or pop-ups and

can be mixed to provide complete coverage. Where evaporation is a concern, however, a drip system will

provide necessary watering very efficiently. A close inspection of the ground surface is necessary to

ensure appropriate volumes and consistency. The goal is to keep the soil near and under the foundation a

consistent moisture (neither wet and/or muddy nor dry and cracked).

An inspection of the sprinkler system should be performed at least twice a year to determine if zones are

functioning properly and if heads are improperly discharging/broken or if leaks have occurred that will

provide uneven watering. This will, in the case of electronic watering systems, require running through the

system to determine if times, duration and frequency have been maintained.

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Vegetation And Trees


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Studies from England and the United States have proven conclusively that trees can cause damage to

foundation stability and in more severe cases complete foundation failure. Engineering studies map the

effect of moisture withdrawal, which can severely damage a slab- on-grade foundation and cause

movement in a pier and beam foundation system." Even when the perimeter of slab has been underpinned,

the interior slab will often deform as moisture migrates to the perimeter as a result of root capillary action.

Planting of shrubs, flowers and trees should be with the understanding of mature growth. Since additional

moisture withdrawal will occur, distance and watering patterns must be planned. If distance away from the

foundation cannot be maintained, root barriers may be necessary to reduce and/or eliminate penetration

under the slab and subsequent moisture withdrawal during times of drought. The depth of this barrier may

vary according to tree or plant root expectations. These barriers, if properly constructed, can also serve as

a moisture barrier, which will add stability to moisture contents under the foundation. Several agriculture

agencies have material available which provides projected root and moisture requirements for different

types of vegetation.

Trees should not be planted closer to the foundation than approximately the mature height of the tree.

Some studies also indicate the tree limbs should not invade the footprint of the house at maturity. There is

a variance with different types of trees that will necessitate their planting even further away. If the proper

distance cannot be maintained, it may be necessary to install a root barrier to reduce the risk of future

problems. Pruning of tree branches so that they do not extend over the structure .can . also be an effective

way to limit root growth under the foundation.

The plants should fit the environment. In areas where droughts frequently occur, it may be necessary to

substitute drought resistant plants and trees to incur less action on the foundation and provide easier

maintenance of the foliage.

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Plumbing Leaks

Leaks in water and sewer lines will change the soil equilibrium under a foundation and can lead to

differential movement/damage. Therefore, it is necessary to recognize signs that indicate problems exist.

If sewer lines are frequently stopped-up and roots are observed when clean-out rooters are used, a sewer

test should be conducted to determine the presence and location of the break. Repair of a break should be

made immediately to avoid damage and future problems.

If abnormal- water bills indicate a sudden surge in water usage, wet spots occur that cannot be explained

or the owner should hear the sound of water running in a bathroom (note: The bathroom nearest the water

supply line will provide the best indication of a water leak), a test of the pressure lines should be

conducted. If leaks are found, they should be repaired immediately.

If hot spots occur in the floor or unexplained water should pool, it is a good idea to call a plumber.

Catching leaks early will many times avoid extensive foundation damage that may be very difficult to

repair.

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Plumbing Leak Repairs

Leaks will often occur under a slab-on-grade foundation that require breakout of a segment of the slab to

gain entry and repair the plumbing. Care should be taken to perform proper compaction of the soil when

repairs have been completed. This will require adequate moisture in the utilized soil and compaction of

layers no thicker than 3" to restore soil bearing to as it existed prior to excavation. The vapor barrier

should be repaired with plastic and a bonding material to provide a vertical moisture stop from vertical

capillary action or water migration that may enter the living space.

Even in the case of post tensioned slabs, a minimum of #3 reinforcing steel bars, at a spacing of 12" on

center, should be utilized by drilling into the existing slab horizontally and epoxying the reinforcing steel

bars to provide integrity. A bonding agent should be utilized at the edges to provide the necessary bonded

joint between existing and newly placed concrete. It is normally advisable to install a moisture shield at

the surface to prevent migration of water through the concrete. This same procedure should be employed


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if it was necessary to break through a grade beam to repair a plumbing line except that non-shrink grout or

epoxy concrete should be used to remold the beam.

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Reinforcing Steel Exposure

Many times concrete will blister or peel along the grade beam and reveal post tensioning cable ends or

conventional reinforcing steel bars. If left unprotected, corrosion will slowly reduce the originally

intended strength of these reinforcing steel members. Therefore, it may be necessary to properly clean the

steel and remove all bond and then install an epoxy grout or non-shrink grout to build back the beam and

protect reinforcement. In more severe situations, it may be necessary to drill and epoxy reinforcement

dowels/ stirrups to build out the grade beam and provide adequate coverage of the reinforcing steel.

|| Top of Page ||

Brick, Rock Or Cladding Cracks

Movement, weathering and freeze damage will often times create cracking in the brick veneer or mortar

that will allow passage of moisture into the vulnerable wall material. Because this will often lead to

deterioration of wood members, it is advisable to seal these cracks with a urethane, mortar or caulk that

will prohibit weathering problems. Where obvious structural problems are visible such a lateral

displacement of veneer, lateral shields or other retainers will be required to prevent additional movement

damage.

|| Top of Page ||

Vent Covers

The original purpose of vent covers is to provide adequate circulation of air under the floor of a pier and

beam foundation so that moisture will not build up and cause deterioration of wood members. Although

coverage of these vents will save money in reducing heating bills, it will often provide the unwanted

environment for wood rot. Therefore, it is not advised that these covers be utilized unless other means of

air circulation are available such as a sub floor vent fan(s).

Recent revelations of houses where the growth of bacteria was so invasive and so deadly that the houses

could not be salvaged, have led to anew examination of detection and prevention of such growth.

|| Top of Page ||

Animal Damage

Dogs, skunks, armadillos, snakes etc. will many times burrow under a slab or pier and beam foundation.

This will undermine the bearing soil and may provide entry for water that was not possible prior to the

excavation. Therefore, it is necessary to back fill the segment and/or place an impenetrable shield to

prevent further entry. It is also important to restore positive drainage to prevent foundation moisture

instability.

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Termite Damage

Wood should not touch the ground at any place near a foundation. This will only invite termites and

provide avenues for their passage to more appetizing segments of the structure. Therefore, the homeowner

should take care to avoid laying, placing or constructing wood that engages the ground. This includes

removal of any wood pieces that may exist in the crawl space of a pier and beam foundation. When you

add moisture to wood on the ground, you provide a perfect environment for growth of termites and other

wood eating insects.

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Interior Doors


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It is a known fact that most slab-on-grade foundations will move

differentially, which can cause misalignment of interior doors. Therefore,

some flexibility in the fit of the doors will reduce the inconvenience of

this movement.

Interior doors should have a minimum 1/8" to 3/16" clearance between

the top and side with the frame. This will allow some seasonal movement

prior to sticking. It is also a good idea to provide adequate clearance off

the carpet or floor to further buffer movement and allow for different

heights of carpet and/or flooring.

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Earthwork/grading engineering - French Drains http://www.eng-tips.com/viewthread.cfm?qid=162089&page=4

1 of 16 24/03/2007 9:10 AM

Home > Forums > Civil / Environmental Engineers > Activities > Earthwork/grading engineering Forum

French Drainsthread158-162089

beryl10 (Chemical) 8

Aug

06

22:52

Hi,

I have a couple questions about french drains. Our property slopes from the street down towards the house and the house sits quite

low in the gound, so, not surprisingly, water has always been an issue. We're putting in some french drains in the front of the house to

intercept the water and move it off to drain pipes running out the back to a stream. These are being placed about 4 feet away from the

foundation. I'm happy with this placement. I think it makes sense.

However, in another area, around the corner on this L-shaped ranch, the contractor is suggesting putting the drains right up next to

the foundation of the house. The house has a basement, and I am not talking about drains at the floor of the basement, but at the level

of the ground outside. I am wondering if this is a good idea. Isn't the french drain actually drawing water towards it, therefore pulling

more water towards the house foundation if there is a 2' deep x 2' wide trench filled w/ gravel right up to it? Maybe all is fine if the

drain works properly, but from what I understand, french drains are not the longest lived drain. They do clog up over time.

Next question, he also said that putting geotextile fabric on top of the drain slows down the percolation of water from the top. So, he

just cut the fabric right off to the surface, which I don't think was very smart. I'd like to landscape right up to the edge of this trench

(make the trench look like a gravel path with stepping stones), and now there's nothing keeping the soil from spilling right in. He just

wants to dump river stone on top w/o the fabric barrier. Any thoughts on not completely wrapping these drains? Our soil tends to be

on the clayey side, but this drain also abuts quite a bit of amended soil (more loamy and organic)

thanks in advance for comments, expertise, etc.

LHA (Civil/Environme) 9

Aug

06

8:10

You are correct on both concerns.

Never put a french drain against a foundation with a basement. However, along the footings is OK, if you put some 3" dia perforated

flexible HDPE, with a filter sock over it. This site will have several products:

http://www.ads-pipe.com/en/index.asp

Can't you grade away from the wall? Even the 4 feet you mentioned in the front is very close. If you can only get several inches of

fall, over about 6-8 feet will help.

Always completely wrap the clean stone in the trench, and overlap a foot or more...for exactly the reason you've mentioned.

Engineering is the practice of the art of science - Steve

cvg (Civil/Environme) 9

Aug

06

12:04


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your contractor is partially correct - the fabric could slow down percolation, especially if specified incorrectly. It would need to be

specified with sufficient hydraulic conductivity to pass the water. In addition, the fabric is designed to prevent the fine soil particles

from contaminating the gravel. By doing that, eventually the fabric could get clogged with silt. Perhaps a better option is to provide

a granualar sand and gravel mixture which will provide a natural filter to your local soil. This can be rejuvenated from time to time

by scraping off the accumulated soil from the surface. If not, you may need to perform the same type of maintenance on your filter

fabric.

Regarding the distance from the foundation, sloping the ground away from the foundation is recommended. A small swale should be

graded over the top of the french drain to allow the water to collect and percolate properly. Recommend at least 2% slope or greater

away from your foundation. With only 4', this provides less than 1 inch of depth in your swale. Would be better if this was 2 or 3

inches.

oldestguy (Geotechnical) 9

Aug

06

21:54

The message you are getting is that you need to filter any water going into a pipe, single size gravel or other drain system. If you

don't use a filter, they will plug up and the whole thing will fail. I've seen gravel backfilled perforated "tile" plug up in one year.

For many years now (since the '30's Corps of Engineers study) it has been known that one of the best filter backfill materials to any

drain is ASTM C-33 fine aggregate for concrete, known as "concrete sand". If your drain pipe has slots in it, you don'teven need to

put a sock on it with this backfll.

I definitely would not set up the situation for surface water to enter the trench backfill, as with a "gravel path". Isn't there any way to

divert this water away, even if you have to install an inlet or two and a separate "storm drain" system?

A clay layer on top of these drain (filtered) systems can be used to keep the surface water out.

However, if you are careful this system described below works well: You may even find a landscaper that has done it. I have never

seen one that knew of this before I taught him.

You mix into the top 2 to 3 inches of soil (any kind) two pounds per square foot of powdered (not granulated) bentonite. It is known

as "driller's mud", avaliable at plumbing supply houses. A roto-tiller works good for this. Don't use an excessive amount or this

"water loving" material will swell and turn the place to grease. The principle here is that this amterial takes on some water and swells

and fills the soil voids. A little does a lot of sealing. It is a natural volcanic clay.

To be effective, this procedure has to treat the whole area of house backfill, not just a few feet out. In most cases, you first strip the

sod off all that backfill. Later roll the sod back and that lawn will stay quite green. Bushes can be left, but work closely around

them.

If you wish, work the worst areas first and see how it works.

Of course you also do all that you can to shed off that surface water anyhow. Don't intentionally try to have surface water soak into

some form of gravel drain. You will regret it.

In summary, protect the ground from water entering, but once it gets in, use a filtered drain system to remove it.

If you find you are getting water in the filtered drain system all year, that outlet should be under the water at the discharge area or it

will freeze and then nothing works.

I've preached this "serman" maybe a hundred times and still find that gravel seems to be in the minds of people as the required

backfill to drains. However, the first underdrain I had installed was in 1954 as a grad student studying them under highways and last


3 of 16 24/03/2007 9:10 AM

time I visited there it still works. I have never found a failure of sub-drains that have been backfilled with concrete sand in all my

working life.

If I was writing the specs for this job I would say "No Gravel Allowed on the Job". The idea seems good (good percolation), but it is

not a filter and it is difficult to keep it protected. You can't goof up the job using concrete sand.


Aug

06

11:36

Thanks for the replies.

We are fairly limited in how much we can grade away from the wall since there are some big trees about 10 - 12’ in front of the

house, and getting too close to them would cause a lot of root damage. We had already created a bit of a swale about 5 feet in front of

the house, and picked that for the location where the pipe was installed. The ditch was dug out 2 feet wide, so the trench begins 4’

from the wall.

I dug out the gravel enough to put in new pieces of filter fabric along the sides so I can wrap the top. In looking at the dimensions of

this trench, I was wondering how this really works. It seems to me the trench would have to fill up with quite a lot of water before it

could even enter the pipe. To be exact, it would have to fill with at least 127 gallons of water before the level is at the pipe (25’ long

x 2’ wide x 4” of gravel between the bottom of the pipe and the bottom of trench). So, isn't a french drain just creating a big basin for

water to collect, only 4 feet from the basement wall foundation, and that the water would probably seep into the soil faster than it

would ever build up to find its way into the pipe, except perhaps during a very big rain. But, then mightn’t a surface drain be more

effective? The direct area of lawn between the house and the street is about 1300 sq. ft., which could, during a 100yr rainfall,

produce 14 gal./min. runoff (based on 3”/hour, and grass surface runoff coefficent of.35), so, yes, it would fill to the height of the

pipe in that situation. I guess my question is this. What happens to all the water that doesn’t make it up into the pipe? Would it be

better to sit the pipe closer to the bottom of the trench? Most diagrams I see of french drains do set the pipes on about 2-4" of gravel.

Or, wouldn't a narrower trench be better. Again, I see alot of them are 2' wide, but if it were only 12" or even just 8", then the water

level would reach the pipe much less water in there.

On paper, the idea of a French drain was great. But, as I look at it now, trench dug out, I do question whether or not this is the

solution. My initial thought on the French drain in this location is that it would act as a curtain or interceptor drain. However, I was

just reading on the NDS website that a French drain can provide this function only if the downhill side is lined with a polyethylene

film.

I have a question to oldestguy: Why don’t I want surface water to enter the gravel trench? I thought with gravel brought up to the

surface, french drains can support the function of removing both subsurface and surface water.

Also, does anyone have any thoughts on some of the prefabricated composite drain systems?

Thanks again to everyone.


Aug

06

12:58

My intent in my first comment was to get you to change the whole system to collect surface water, separately from ground water.

Also, you may see that I recommended two things more: Seal the ground surface and install a subdrain.

However, let's look at what you have and see if that can be fixed.


4 of 16 24/03/2007 9:10 AM

The term "French drain" in my view is an old fashoned way to collect ground water and divert it from an area, such as an orchard or

farm area in low ground. It is not a filter and in time can plug up. It is not a system for collecting surface water specifically.

What you have built is not such a ground water collector. It appears to be a collector of surface water and designed so that the water

collected also can soak into the ground and then affect your basement. I suspect your "contractor" is some sort of impractical

dreamer, certainly not using common sense.

My recommendation is that you get rid of the "contractor" and get someone on the job with common sense, if you need help, to

correct things.

Since you have a trench filled with gravel, you might change this to a surface collector only and perhaps that would do the job. But I

doubt it. If you want to stick with the trench OK, but it would not be as permanent as if you had a shallow "ditch" or swale, lined or

made water proof, possibly with the bentonite treatment of earth. Any place you have water in contact with earth is a place for water

to infiltrate. House backfill is usually loose and water easily enters.

Sticking with the current trench:

To make this a surface water collector, this needs to be a waterproof container. Lining it, sides and bottom, with plastic is a thought,

but I have never seen plastic to be totally waterproof, unless you seal all the seams. Concrete is better, but not perfect either.

Sealing the lining to a drain pipe also is needed and that drain pipe should be at the lowest elevation in the trench, and sloped down

from there. The pipe should be solid walls, not slotted.

If it was me, I'd bite the bullet and do this minimum step: But think about the affect of later doing the sub-drain as if affects this

work.

Dig out the gravel and fill the trench with earth, preferably silty clay or a bentonite treated sand. Compact it if you can.

Waterproof the whole house backfill area at least on the uphill side with the bentonite treatment and slope everything to the filled

trench area, which is then shaped like a swale and sloped to inlets. This is a surface water collector only.

These inlets can be purchased at plumbing houses and sealed to plastic pipe to carry off the water.

Lacking the inlets and drain pipe, continue the swale around the house and off from the house area.

If you really want to use "suspenders and belt", you first dig down alongside the upper foundation walls and install the slotted plastic

sub-drain that is totally separate from the surface drain work. Use the concrete sand as the backfill up at least a few feet above the

basement floor. The slotted pipe should be a low as possible, along side the footing if possible. Give it some slope if possible, but

not mandatory. Use excavated soil for the remaining backfill.

Then do the surface waterproofing and swale as described above.

With what you now have I think you will see more water in the house than before. I am sorry I did not explain this before, and, I

probably did not clearly explain that it is the wrong thing to do, in my opinion.

You should know that I have fixed many a site such as yours and that it is not always possible to stop all seepage. Sometimes water

enters the house backfill far from where it then gets into the basement. Therefore you usually have to work in steps, get the most

obvious done first and observe.


Aug

06

16:58


5 of 16 24/03/2007 9:10 AM

Thanks for the response. You were clear the first time, but that drain was already in. And, the contractor already fired. Though, that

was due to other sloppy work. If I were doing this project again, I would first hire an engineer to design the plan, and not just hire the

guy who calls himself a drainage contractor. Live and learn.

After the whirlwind of activity around here, and several problems with the contractor, I starting thinking more and more about this

design. Though I initially thought a french drain in front of the house to collect and remove surface and subsuface water flowing

towards the house made perfect sense, I later starting seeing flaws with this as a solution. However, I've read about french drains

being used in this manner - wrapping the house on the uphill side, a few feet away from it, and I initially thought it seemed logical.

Anyway, what I'm now thinking I could easily do is to just dig out the gravel, and replace the slotted pipe with a solid pipe and

connect several catch basins along the length. This pipe would be 5' from the house (b/c thats where the slotted pipe is and the

connection to the drainpipe going back to the stream), and the catch basins would sit in a bit of a swale.

Any comments on this idea are welcome.

thanks.


Aug

06

12:31

OK a good explanation.

Well, as I uderstand it, the sides and bottom of this filled trench still are in contact with the soil and not sealed, as with a plastic

sheet. Thus, before the water is in the pipe and flowing away, it has the chance to infiltrate soil backfill to house and affect the

basement. Usually backfll was shoved in with sloping "layers", that promote the ability of the water to seep toward the basement.

So, If you are going to replace the pipe anyhow, why not at least seal the bottom and sides of the tremch.

If gravel is to be used again and some inlets are to be installed, I am assuming you will have them in the base of the trench, right?

In that way you may not be able to correct possible plugging of the gravel with sllt in time.

I know it is more work, but why not forget about this trench thing and fill it with soil, placing your inlets where you can see

them? You still can use the trench for the discharge line.

And if you wish to waterproof the ground surface with the bentonite treatment, it will tie in more easily with your surface water

collection system.

The gravel thing is likely to be a maintenance head ache for years to come.

If you gave thought to use a bentonite treatment of the gravel for salvaging it, yet making it water tight, I think that will take some

experimenting with varying precentage of bentonite, soak it and see what happens. This can be done in a 5 gallon bucket with

bottom perorated. Too much bentonite and swelling may amaze you.

geosavvy (Geotechnical) 22

Aug

06

16:49

Bentonite is nasty stuff. Make sure you get your blend right before you spread it willy nilly.


6 of 16 24/03/2007 9:10 AM

Also, I personally would recommend against using any type of soil filter material. The gradation of the filter material has to be

customized for the type of material you are filtering, else the particle arching required to filter will not happen. Its easier to go with

the local tried and true geosynthetic fabric that works for the soils in your geologic area.


Aug

06

12:05

Sorry, this is kinda long, but I'm just trying to understand a couple things.

It seems as though a lot of people on this forum aren’t so in favor of using a shallow French drain to collect, move and divert water

from running towards a house where the property slopes towards it, yet, a lot of other people (landscapers, drainage parts stores,

gardening forums) seem to think they’re great. I am no longer very convinced that they are a good solution to what is probably

mostly a surface water issue, however, I’ve become obsessed with thinking about how water moves through the landscape, and soil,

so, I have a couple questions.

1. If the coefficient of runoff for grass is .35, I assume that means that 35% of the rainfall flows over the surface and 65%

percolates into the soil. So, where does that 65% of the water go once it percolates into the soil? Does it move horizontally below the

surface until it finds its way to the bottom of the hill? Or is that majority of that 65% of the water getting used by the grass, trees and

other vegetation before it has a chance to move down slope?

2. Why doesn’t the calculation for runoff take into consideration slope? I assume that slope must make a big difference, and on a

steep grassed slope, more water is runoff than on a shallow slope where it has more time to percolate into the soil.

3. If a French drain (not lined with anything impermeable) daylights (to collect surface runoff in addition to subsurface water), how

much of the total water actually makes its way into the slotted pipe versus percolating through the ground at the bottom? In a slow

but steady rain, could the water actually penetrate the soil beneath the pipe faster than it builds up to a level high enough to enter the

holes on the bottom of the pipe? I guess many factors affect this, including how saturated the soil is to begin with, the permeability of

the soil, and even the dimensions of the French drain trench (width and depth below the pipe determines how much water must fill

before it reaches the bottom of the pipe).

4. What system would collect more water? A series of surface drains or the French drain with gravel to the surface?

Here's my thinking on this:

If we can assume a surface drain collects 100% of surface runoff, which is 35% of total rainfall on this grass covered sloping surface,

then 35% of the rainfall will be removed by the surface drains.

If the French drain trench captures 100% of the surface runoff (35%) + some fraction of subsurface water (the 65%), LESS the

amount that percolates into the soil below the pipe, what total percent is entering the drainpipe?

Of course, I have no idea what percent of the subsurface water it will capture, and what the loss from percolation below will be. But,

if the fraction of subsurface water that enters the trench is much larger than the total loss to percolation below the trench, then a

French drain is the better system. But, if the percolation into the soil is high, and/or the amount of subsurface water entering very

low, then surface drains are the better solution.

I don’t suppose there’s any rule of thumb for this, is there?

Am I over thinking this?

The trench is already there and I can finish it off as a french drain, or put in solid pipe with a few catch basins and inlets. I don't feel


7 of 16 24/03/2007 9:10 AM

like experimenting with the bentonite or other methods of making the trench impermeable. If percolation is a big issue, esp. 4 ft. from

the basement wall, I'd go with the solid pipe and inlets.


Aug

06

12:41

to answer some of your questions -

Percolating water generally moves vertically downward unless there is some driving force such as daylight, an embankment or

impermeable layer that forces it to move horizontal. Once it leaves the french drain trench, it may not daylight.

The rate of water use by plants is slow and doesn't have a very large effect on the amount of storm runoff or soil percolation. The

65% is retained, soaks in, evaporates and some is transpirated by plants - but does not run off.

Runoff calculation does consider slope – it is a function of the time of concentration. For higher slopes or smoother surfaces, runoff

velocity is higher and the time of concentration is smaller - consequently, the peak runoff is higher

Water will seek the path of least resistance – if a smooth pipe is there it will flow through the pipe much faster than it percolates into

the ground. This is one reason to provide a pipe in a french drain (assuming the purpose of the french drain is for removing water

rather than for allowing the water to soak into the ground)

What system would collect more water? Depends on the design, but surface drain is probably more efficient at removing stormwater,

if the stormwater can be directed to the drain before it soaks into the ground…


Aug

06

13:01

But, if the french drain pipe is on 4" of gravel above the bottom of the trench, doesn't the trench have to fill up with 4" (actually 5"

since the holes are a little off the bottom) of water before it gets to the pipe? At the dimensions of the current trench (28" wide x 25

ft. long) it would fill in with 127+ gallons of water before reaching the pipe. A big storm would of course fill it at 14GPM which

would reach the pipe quickly, but for the smaller rainfall amounts (lets say, 1GPM over the course of a day) it might never fill it

enough to reach the pipe, right? then could percolation exceed the rate at which it fills?

i guess this is my fear. that we're putting more water into ground close to the foundation than w/o the trench.


Aug

06

13:20

some water will percolate down, hit the pipe and run into a hole without ever reaching the bottom of the trench. Also, you are vastly

overestimating the amount of water necessary to fill your french drain trench. It is filled with gravel or sand which occupies most of

the space. Water only fills the volume between the grains of sand. I would guess closer to 20 or 30 gallons of water maximum to fill

the bottom 4 inches.


8 of 16 24/03/2007 9:10 AM

However, as recommended by oldestguy - to remove surface water, I would stick with a surface channel and grated inlets into your

(non-perforated) pipe. If you are trying to lower water table next to the house, then use the french drain with the perforated pipe.


Aug

06

13:22

ah, yes, I totally forgot about all the space taken up by the gravel.

thanks.


Aug

06

16:27

How does one determine where the water table is? I assume to lower the water table, the french drain has to be very deep.


Aug

06

16:38

I don't know if any of you are familiar with the "Ask the Builder" website. Here he explains water movement through soil and using

the french drain to protect ones foundation.

"When it rains, water enters soil and pushes the air to the surface. Gravity then takes over. If your yard slopes, the water within the

soil actually begins to flow downhill."

"A linear french drain is simply a "moat" that protects your yard or house from sub-surface or surface water. You construct it by

digging a 6 inch wide trench approximately 24 inches deep. .... If your intent is to protect your house from water, you construct the

trench approximately 4-6 feet away from the foundation. In many cases the trench system is U shaped as it passes around your

house."

He extends the gravel to the surface to collect surface water.

http://www.askthebuilder.com/175_Drying_Soggy_Soil_-_A_Simple_Trench_Drain.shtml

All the explanations I've gotten through this forum make alot of sense, but then so does Ask-the-Builder, to some extent.


Aug

06

17:49


9 of 16 24/03/2007 9:10 AM

percolation is driven by gravity and as such, the only way it can "flow downhill" is if there is something blocking it from going

straight down such as a layer of rock or clay or an easier path to follow such as through a pipe, through a crack etc.

"Bob the builder" has a degree in geology, but apparently according to his profile on the website, has earned his living flipping

houses and never practiced engineering.


Aug

06

21:22

Hi again:

I think too much time and worry is being done about quantities and rates of water flow. Heck, storms are all different and that once

in 10 year thing may be carried OK by the job built, but the once in 20 or more years won't. Intensity of each rainfall also is

different.

So you really probably are not in a position to worry about which your system will take. You just build it as big as practical and take

simple other precatuions so that any standing water won't run into window wells and other places of concern.

I take exception to a few statemsnts made above. The best all around filter for subdrains is concrete sand, for all soils. You don't

need to worry about gradations of those materials either. Where there may theoretically be fine clays that theoretically will pass thru

the voids of the concrete sand, well don't worry. The cohesion of that clay material keeps it in position pretty well. THAT CLAY

IS UNLIKELUY TO SEEP ANY WATER ANYHOW. It is the sand seams that do the seepihg and they are held back by the

concrete sand.

Another thing about concrete sand. It is darn difficult to foul up the the job. On too many jobs, asking for complicated procedures is

asking too much of the usual contractor doing small jobs. Then too you get the guy that has been using questionable practices (such

as using gravel around sub-drains), of recommending these "french drains" and he "knows better" and keeps doing it the same old

dumb way.

Also, water seeping into basement backfill will follow the the path of least resistance and it usually is not straight down. It usually is

slanted towards the wall, due to the usual way this backfilling is done. Thus water soaking in 4 feet from the basement wall will flow

towards the wall on that slope.

Take to heart my philosophy about construction:

IF SOMETHING CAN GO WRONG ON CONSTRUCTION, IT WILL GO WRONG.


Aug

06

23:21

Yes, I probably have been over calculating, but was just trying to quantitatively understand how well a French drain removes water,

and where the water is coming from. When we talk about subsurface water, does one mean 1 foot down, or 5 or 10? With a ditch

only 1.5 feet deep, how much subsurface water would a French drain even intercept? These questions are what led me down the

quantitative road wondering, would this French drain put more surface water into the ground than the amount of subsurface water it

removes?

So, anyway, I am going to install a solid pipe w/ 5 inlets (catch basins) along the 25’ length, and backfill with soil. Forget about this

whole gravel pit. I hope this will prove to be the right decision, as moving tons of gravel is no small chore, and now I’m stuck with a


10 of 16 24/03/2007 9:10 AM

pile of gravel (guess I can use it for a foundation for that garden shed I’ve been wanting to put up).

Why do you think everyone backfills with gravel, when concrete sand is superior?

Does the backfill against a basement foundation really go out 4 feet away from it?

Even though I’ve abandoned the French drain, I was wondering whether clogging really such a big an issue with the stiff HDPE pipe

that has 2 rows of fairly large holes along the bottom compared with the corrugated pipe with slit type holes all the way around? Do

roots tend to go into these holes? I was amazed how many fine roots have already grown through the geotextile fabric, though

wondered if they would continue on through the gravel to find their way into those holes. It seems it would be difficult to plug them

up with silts.

blueoak (Civil/Environme) 24

Aug

06

23:59

Sorry oldestguy, but I disagree with your filter statement. I think for residential and other little jobs spec'ing concrete sand is fine and

your advice for this job is excellent.

But if you need a filter on an important structure you need to do the work on designing a filter. I home isn't that big a deal to the

neighbors, but a dike or dam with fines migrating downstream is a little more important. Concrete sand isn't always applicable and

what about filter design below riprap or gabions.


Aug

06

12:17

I'm rereading this whole thread and see that I asked before why one wouldn't want surface runoff going into a french drain, but I

realize I still don't quite understand why. Is the simple answer that not enough of it gets transported away in the slotted pipe? I

understand not feeding a gutter leader directly into the slotted pipe, but why not the runoff from the surrounding lawn into the gravel

trench with the slotted pipe?

I'm still questioning this b/c this will be alot of work to change, and wonder if its all that bad to leave it as a french drain.


Aug

06

13:06

french drains are ideal for intercepting and draining subsurface water. However, surface drainage is most efficiently removed using

surface drainage methods such as a swale or grated inlets into a pipe. Intercepting surface drainage with a french drain will increase

the amount of water that infiltrates into the ground at that location. You never said that you had water coming into the basement

through the foundation walls, however, by putting a french drain near your foundation and allowing it to also intercept surface water,

you could possibly create another problem rather than solve one.


11 of 16 24/03/2007 9:10 AM


Aug

06

13:25

thank you. That was the direct, to-the-point kind of reply I needed to hear. Really, it was my question that needed to be more direct.

With all my convoluted calculating I didn't ask the direct question.

Anyway, no, there is no water coming into the basement through walls. That was taken care of ages ago with, I guess, perimeter

drains (french drains?) in the basement leading to 2 sump pumps. That was before my time. As long as the pumps work, all is well,

although damp.

BigH (Geotechnical) 26

Aug

06

5:42

blueoak - see Terzaghi Peck and Mesri. Oldest guy is correct that for any fine grained soil, the use of concrete sand is "fine". This

was first told to me by Charles Ripley of the old Ripley Klohn Leonoff of Vancouver - and one of the pricipal sources for that given

in TP&M. For coarser soils, you will design the filter - but remember that a lot of work has been done over the years with respect to

the original equations and filter criteria. I suggest too that interested members read the few pages in Conduto's book on Soil

Mechanics and they will see a good summary of "filter" criteria for finer grained soils. This is also give in one of the US military

manuals.

With respect to cvg, if the soil in which the french drain is placed is clayey or low permeability soil and the material in the french

drain is sufficiently permeable, I doubt any of the water will enter a pipe anyway and he suggests but apparently - cvg must be

assuming that the holes are pointed up when he indicated that 'some' water would enter the holes - although it is more conventional

and in line with AASTHO recommendations to place the holes downward. A pipe, in my view, is really only necessary if you have a

large volume flow of water - or, since the pipe is not very expensive you put it in for redundancy. Very few early-on french drains

ever used pipes. I would put them in only if I believe that it is necessary to do so in order to ensure tha the french drain doesn't build

up an appreciable head of water.


Aug

06

5:45

oops - " . . . as he suggests . . .", not " . . . and he suggests . . ."


Aug

06

9:14

BigH - The french drain was built with a pipe, holes facing down, connecting to a solid pipe that the gutter leaders and sump pump

tie into and runs out to a stream at the back of the property. The french drain is only in the front of the house. It has gravel surfacing

to the top. No soil on top. Is meant to intercept surface water running down the sloped lawn in addition to subsurface water. So, why

do you say the water wouldn't enter the pipe? Or do you mean that subsurface water doesn't seep out of clay soil very well?


12 of 16 24/03/2007 9:10 AM


Aug

06

13:38

Hi All:

A fun topic, and I trust all is pretty well resolved at the house in question.

Now for blueoak and the "disagreement". Really there is no disagreement, since I refer to "subdrains" as being most suitably

backfilled with concrete sand. Let's define "subdrain". My use of that term "subdrains" started in 1954 (when I did my Master's

thesis on highway subdrainage at Cornell). The term comes from what Armco Steel put out years ago in their "Soils Manual', or

similar name. A subdrain,in my terminology, is mainly used for draining ground water. It is not generally a term used for toe

drains at earth dams or other important structures where the drainage is not generally taking ground water, but rather seepage water in

large quantities, etc. Yes, using the accepted ratios for filter design is a good idea for these jobs. But, for highway roadway frost

heave areas, base course drainage, house basements, etc. it generally is the case that designing a filter is not practical and usually not

needed.

Then comes what about the pipe and holes? Armco's original "wrinkled" corrugated steel subdrain pipe had its holes on the

underside at the quarter points, 3/16" diameter. Under heavy flow of water some of the finer grains got in, but soon the coarser

grains bridged over those holes.

For the more recent wrinkled plastic pipe with slots, maybe 1/16" wide, some sand also gets in and a bridging over then takes place

also. I have heard complaints by state code folks that they have seen the fabric sock on these pipes clog over at the slots, but I have

not seen this happen. Maybe these cases were backfilled with gravel? None of the installations I have been involved with used the

sock and they all seem to function fine. Since no excess sand gets into the pipes causing problems, we also no longer ask for

clean-outs to be installed, just in case.

The reason I am so against any gravel on the job is that we once called for using gravel directly around the pipe, with concrete sand

under, beside and over this gravel, something one would design with the filter ratios. A difficult thing to do, but it looks nice on a

drawing, to satisfy the architect who likes the term gravel for some reason.

Well I stopped by the school job where this was to be done and there the skid loader had dumped load after load of gravel over the

pipe two and three feet high, totally in "violation" of the nice looking drawing. After that, all gravel was removed from drawings and

the dumping of concrete sand was the case, and that has worked fine. As I have said before, it is difficult to goof up the job when

only concrete sand is the backfill, (at least around the pipe) .


Aug

06

9:45

beryl10 - it was more a general statement. The critical point in french drains is that the drain drains somewhere and the permeability

is sufficiently high (usual greater than 1 cm/sec) that water passes out quickly. Optimally, your french drain is connected by gravity

to an outlet. You may need some significant volume flow in order to fill up the drain rock below the pipe in order for the water to go

into the pipe. If you have the flow, the pipe will drain water; if you don't, the pipe will remain dry and the water will be passed by the

drainrock beneath the pipe. Now if your french drain is not connected in a positive fashion and you are relying only on the pipe to

drain water, then it really isn't a french drain but more like a "storage" pit.

blueoak (Civil/Environme) 31

Aug

06

14:09


13 of 16 24/03/2007 9:10 AM

Oldestguy,

Thanks for the definition and correction. I have been stuck with embankments lately and am a little shortsighted.

BigH,

As always good references. I am a little worried though that "concrete sand" can mean too many things. I have seen "concrete sand"

tested that didn't meet filter requirements on a clay dam.


Sep

06

3:30

blueoak - you are correct in that the concrete sand may not meet the filter requirements against the clay in a dam - but one must

remember the underlying assumptions under which the filter criteria were based; and it is my recollection that the filter criteria were

developed with coarse grained soils in mind (sand, gravel) not with clay to sand. Clay's biggest problem in dams is with its

propensity towards dispersion and that is why they have developed the pin-hole test back in the early 70s. Concrete sand basically

means normal well graded coarse medium to fine sand in my view. Again, see Conduto, see Terzaghi Peck and Mesri - and, if my

memory serves me right, Milligan in one of the recent Terzaghi lectures (2002 to 2004) discusses this in his paper.

As well the infamous filter criteria, many love to use Hazen's Rule for the determination of "permeability" although one will have

problems whether to use 100 or 150 as the coefficient. But, the Hazaen's rule was developed for medium grained single sized sand -

yet, most texts do not point this out and engineer's over the years have used it irrespective of its assumption.

oldestguy - 1954, eh? Were you there when Cornell beat Ohio State two years running in football? Do you realize that Cornell

holds a 2-0 record agains that Big 10 powerhouse???

oldestguy (Geotechnical) 3 Sep

06

10:58

Big H

Nice to see another Cornellian. Can't recall. Undergrad time was '46 -51 (5 year course) then the 3 years in navy (you remember

NROTC?) before grad school there.. In undergrad days I was too poor, so I was an usher at the games. I only recall Army beating

the Big Red about '47.

That job was at Judd Falls road, near campus.

newoldguy (Geotechnical) 11

Sep

06

11:00

Some great information here.....Please help with a couple of questions... I am planning a curtain drain to be placed

about four feet out from the foundation of a house with a damp basement. I am planning to go down six to seven feet

and I like the discussions about concrete sand with drain pipe.Does the sand need to be "washed sand"? Any warnings about going

that deep with a "sand only" backfill?



14 of 16 24/03/2007 9:10 AM

Sep

06

15:52

OK to the Newoldguy: The concrete sand I refer to meets ASTM spec C-33 for fine aggregate. It very likely is washed to get to that

gradation. In this neck of the woods they call it "Torpedo Sand" for some reason.

The obvious thing you want to do is cut off the flow towards the wall. I don't like the idea of anyone in a trench that deep unless it is

sheeted and braced. With no one entering the trench, this works most times. You follow the back-hoe excavator and immediatelty

roll in the 4" corrugated slotted plastic pipe and immediately dump some concrete sand on it. With that you then are 90 percent

done. For cost saving you might then follow with a local bank run sand up to near the surface where some impervious fill would top

it off. Should some cave-in occur, usually this method will still do the job. If you wish to try to compact the backfill, it depends on

your site. For some reason I don't recall having any later settlement problems on the jobs with no concerted compaction effort. Per

your question, I don't see where any "risk" comes in with sand backfill. The concrete sand does an amazing job without much

work. A little enters the slots, but then it stops due to bridging by coarser grains.

I'd not use this system for surface water drainage, as this thread is involved with.

With this method you may find the bottom of the trench and the pipe may not stay on a nice grade line. Therefore, going deeper to

allow wome wiggle room might be in order. The deeper the better for protecting the structure from water, but it might undermine the

footings.

You can see that doing it this way, it is difficult to goof it up.

Next is where to drain it to. On some jobs we install a man-hole and an electric sump pump, or run it to daylight down the hill. In

any case, if you are in cold climate, that outlet needs protection from freezing. An outlet under a lake is ideal. Your local codes may

allow it to go into the basement with a sump there and discharge to where they allow.

As an altrnative to the trenching some contractors will talk the owner into allowing a trench to be cut thru the floor next to the wall

and install a drain pipe there. It may work, but I've see these with water then seeping up out in the middle of the basement

floor. Perhaps the drain was not deep enough then.

jtc500 (Civil/Environme) 11

Sep

06

20:45

I have recently become part owner of a small rancher on a poorly drained site.I have decided to install a perimeter drainage system

and after much research conclude that concrete sand surrounding slotted plastic pipe (no socks) will be my choice method. It also

seems to me that if this system were to fail some time down the road that it would be a lot easier to dig out and replace than a system

involving sone or gravel.I also think I saw research many years ago claiming that uniform sand at 2mm would resist the passage of

termites.This foundation is only four courses high. In most areas except on the driveway side I think a 30" trench would be about

right dug to bottom of footing (angling slightly deeper going out)Probably will use one slotted 6" pipe but two or three 4" pipes

sound right also. Will tie into outside sump crock and try to pump to street.Cannot wait to start when I get some free time.I am 10

year bulder turned 25 year arborist-treeguy who would appreciate comments.

fattdad (Geotechnical) 11

Sep

06

21:37

I liked oldestguy's reply regarding the definition of subdrain. Regarding the use of crushed stone, washed sand or something


15 of 16 24/03/2007 9:10 AM

in-between what's at issue is matching the grain size of the sand/gravel material to the slot size and the grain size of the water-bearing

formation. If I were at work right now, I'd give the basic guidlines, which relate to the D10 (or is it D20) and the D60 size. It's fairly

straighforward. That said, in this day and age, most just don't fuss with all this calculating 'cause there's filter fabric to rely on. In

some instances this can be false security.

Regarding the attraction of water to a subdrain from that basis avoiding the use against a below grade wall, I would not share that

concern. If you have positive drainage, it just would not be an issue.

fatt but-but-not-that-old-I-guess dad


Sep

06

20:12

ITC500 Nice to see you are planning a perimeter drain, doing something line a "buried moat around the building". The idea would

what I call a cut-off drain, cutting the flow toward the building. In my research I found it impractical to depend much on drawing

down the water table, by installing a low placed subdrain to hope the water will run to it. The main place you can hardly get away

from doing this is for agricultural drainage or athletic fields. For a football field I call for drains under the main yard markers, as

well as a perimeter drain. The aim is mainly to drain off rain water from in the soil, using the draw down effect. Not perfect, but it

works sufficient for play to go on.

So at a house, if possible, it also is a good idea to get some drains inside the building in case some water for some reason gets past

the outside drain. In sandy country these should be no farther apart than 15 feet, since most sands are not highly permeable and a

steady flow gradient of about 1 in 7 seems to be common.

Pipe size of 4 inch is plenty large enough for even the heaviest groundwater flow (usually). I do recall one 8 inch line flowing half

full for drainage of a road cut in gravelly sand.

jtc500 (Civil/Environme) 14

Sep

06

0:23

Thanks much oldestguy for your response.I am however dealing with a four block crawlspace with duct runs below making the

prospect of installing an interior drainage grid system scare me a bit.Of course down the road I might be forced on my belly to do just

that.It does occur to me also that since a dwelling routes the rain water outside the perimeter drain changes the problem at least a

little from the exposed football field example.Say the water table has risen to the bottom of the footing.If even more water was

introduced ouside the perimeter would that water not take that first and easy path to the drainage trenches.Of course I can also see

that the faster water is added would require wider and deeper trenches for a dry interior.


Sep

06

20:57

jtc500 The crawl space thing is different from what I had presumed. I was thinking of deep basement.

I suspect you are just trying to keep severe dampness from inside, as with "ponding in there". Your perimeter idea sounds good and

probably all that is needed in that case, assuming bottom of crawl space is a foot or more above your drain elevation. Hold off inside


16 of 16 24/03/2007 9:10 AM

work until you see what outside work does.

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DECEMBER 2005 I JLC I 1

Foolproof Cure for Wet Basements

While listening to a home-improvement call-in

show on the radio the other day, I was struck

by the large number of callers who sought solutions to

wet-basement problems. Not surprisingly, the nation-

ally syndicated columnist who hosts the show said that

wet basements are the leading source of letters and

e-mails sent to his weekly newspaper column.

Barrier System vs. Water ManagementMy company, Tri-State Basement Systems, based in

Berlin, Vt., concentrates on basement waterproofing

and, as the radio show indicated, there is always plenty

of work. Unlike most DIY efforts and “miracle coat-

ings” that attempt to prevent ground-water entry with

a barrier, our techniques don’t try to stop the water, but

rather to manage it. Sometimes we use exterior

perimeter drains and waterproofing, but more often

we install water-management systems on the build-

ing’s interior. Most homeowners prefer this approach

because it costs less than excavating around the foun-

dation and is less destructive to their landscaping.

One recent project involved a 1950s ranch home with

a block foundation. The basement in this house was

literally soaking wet. Water running down the walls

accumulated on the floor, making the space virtually

unusable — even for storage. And when you opened

the basement door, you were greeted by a wave of

humid air and the pungent smell of mold. The home-

owner had tried numerous coats of waterproof paint,

grading around the foundation, and a cheap sump

pump illegally piped into the waste stack, but all these

efforts were of little help. Another contractor suggested

by Scott Anderson

Skip the exterior excavation and

waterproofing — an interior perimeter

drainage system can work just as well



Figure 2. The author’s crew often uses mattocks and hand trowels todig the trench along the inside of the footing (left). Next, workers drilla series of 3⁄8-inch weep holes along the base of the foundation wallwith a rotary hammer (above). Water often pours out of the wall forseveral seconds after a hole is finished. The bottom of the trench islined with a layer of crushed stone.

Figure 1. Electric jack-hammers are used to cut a trench around theslab’s perimeter. Thejackhammer makes lessdust than a concretesaw and can break uprocks or other obstruc-tions under the slab.Note the wet floor andmold on the walls.

excavating around the foundation and

installing a perimeter drain, but the plan

was twice as expensive as ours and

required removing a large deck.

So the homeowners decided to treat

the problem using the WaterGuard sys-

tem, one of the proprietary basement-

drainage systems manufactured and

supplied by our franchiser, Basement

Systems (800/638-7048, www.basement

systems.com). WaterGuard is a perimeter

drainage system installed on the inside

of the foundation. We dig a trench

around the perimeter of the basement

slab and install perforated pipe that

drains to a sump. The collected water is

pumped through a 2-inch pipe to the

building’s exterior. We give our custom-

ers a lifetime guarantee on the work we

do, and we almost never get callbacks.

TrenchingThe first step is to break up the floor at

the edges of the concrete slab to create a

5- to 6-inch-wide trench around the

perimeter. We use electric jackhammers

instead of concrete saws because the

jackhammers create less dust and can

cut through slabs of almost any thick-

ness (see Figure 1, previous page). Also,

the rough surface created by the jack-

hammer helps to key in the concrete

patch at the end of the process. As we’re

running the demo hammers, we carry

out the concrete rubble in five-gallon

pails.

Once the slab is cut around the

perimeter, we clean off the footing and,

just inside it, dig a small trench about

4 inches deep. While one or two crew

members are excavating the trench,

another drills a series of weep holes in

the base of the wall with a rotary

hammer (Figure 2, previous page).

Water stored in the cells of the concrete

blocks often pours out of the wall for

several seconds after a hole is drilled.

We line the trench with 2 inches of

crushed stone and install our propri-

etary WaterGuard drainage pipe, slop-

ing it toward the sump 1⁄ 4 inch over the

length of each wall. There are two

styles of WaterGuard pipe (Figure 3).

The standard version is placed directly

against the foundation wall with a plas-

tic flange extending up the foundation

wall. The flange is designed to leave a

small gap along the wall so any water

flowing down the wall can reach the

subslab drainage pipe (see “Basement

Interior Drain,” next page). The other

version works similarly, but comes in

two pieces. It’s used in applications

where the footing prevents placing the

drainage pipe against the foundation

wall. The pipe comes in 10-foot lengths

that we miter at the corners with an

inexpensive miter saw.

Installing the SumpWhile the drainage pipe is being installed,

we start digging the sump pit. Water often

fills the hole as we’re digging, so we need

to bail as we dig. Again, we use pails to

carry out the rocks and muck.

When the hole is finished, we place a

layer of washed stone in the bottom,

insert the sump liner — making certain

it’s level — and then backfill around the

basket with washed stone. We connect


Figure 3. The author uses two styles of proprietary pipe. The standard type (above) is placed against thefoundation wall. It has a toothed flange that creates a small gapbetween the basement wall and slab so any water seeping through the block is directed into the pipe. The job described here required the two-piece version (left) because the foot-ing prevented placing the pipe againstthe wall. The piping is sloped towardthe pump (below) — 1⁄4 inch over thelength of the wall is usually enough.


12"- to 16"-wide trencharound slab perimeter

Existing slab

Existing footing

WaterGuard drainage pipe withweep flange (allows any wall seepageto reach subslab drainage pipe)

One-Piece Drain

Two-Piece Drain

Perforated sump basket

Weep holes drilled along baseof existing block foundation

Pump stand

Discharge pipe

High-water alarm

Pump

Airtight floor drain

Existing footing

Existingblock wall

Crushed stone

Existing slab

Concrete patch

Crushed stone

Drilledweepholes

Concrete patch

Two-piece WaterGuarddrainage pipe, weep flangeplaced against wall

Basement Interior Drain

WaterGuarddrain outletadapter


WaterGuard drainage pipe comes in one-and two-piece configurations. The one-piecepipe installs more quickly, but the two-pieceversion is needed where there isn’t enoughspace to place the pipe between the slaband the top of the footing. Both types have aweep flange, which allows water seepingthrough the wall to reach the drainage pipe.

the sump basket to the WaterGuard pipe

with a proprietary adapter and a length

of 4-inch PVC (Figure 4).

The sump we use has features that

improve its performance and durability,

including a perforated basket to drain

water from below the floor and heavy-

duty plastic components. The high-qual-

ity Zoeller pump (800/928-7867, www.

zoeller.com) is placed on a plastic stand,

which prevents the pump from clogging

with sediment (Figure 5). The sump

basket has an airtight, two-piece, screw-

down lid to prevent kids and pets from

getting inside.

Running the Discharge LineWith the sump pump installed and the

cover in place, we run the discharge line

up the wall and across the ceiling to the

exterior. Ordinarily we take the most

direct route, but sometimes we’ll go out

of our way to place the outlet in an in-

conspicuous spot on the home’s exterior.

The discharge pipe is tucked inside a

joist cavity whenever possible so it won’t

interfere with finishing the ceiling.


Figure 5. A plastic stand (above) raisesthe pump about 6 inches above thebasket’s bottom so it doesn’t clog withsediment. Flexible couplings on thedischarge line (right) and a two-piece lid(far right) allow the pump to be removedwithout cutting the pipe.

Figure 4. An adapter (above)connects the uniquely shapedWaterGuard footing drain to a lengthof 4-inch PVC pipe that runs into thesump basket. Workers use a jigsaw to remove the knockout in the sumpbasket (above right); then they levelthe basket and backfill around it withwashed stone (right).


Where the pipe exits the house, we

seal the penetration with urethane

caulk and install a plastic trim ring for a

finished look.

Preventing the discharge line from

freezing is an important consideration in

our area, where winter temperatures can

stay below 0°F for days. If the outlet were

to freeze, the pump would still run, but

the backed-up water could cause a flood

or pump failure. We use a proprietary

outlet called an IceGuard, supplied by

our franchiser (Figure 6). It has openings

that allow the water to escape even if the

pipe below becomes clogged with ice or

debris. We also slope the discharge pipe

down toward the outside so water won’t

remain in the pipe near the outlet where

it’s more vulnerable to freezing.

To direct the discharged water away

from the foundation, we use a couple

of methods. The least expensive and

simplest option is to install a plastic tray

called a Rain Chute (Figure 7). The

chute has low-profiled sides so you can

mow right over it, and it’s placed in a

sloping trench so the water is carried

away from the house. We’re mindful of

where we locate the open-ended chute;

we don’t want the discharged water to

Figure 7. Because manyproperties may not haveenough slope or a conve-nient spot to drain todaylight, running a pipeunderground is not al-ways an option. In thesecases, a plastic traycalled a RainChute isinstalled in a slopingtrench to carry wateraway from the house(right). It’s placed slightlybelow grade so a mowercan run over it (far right).


Figure 6. Here, the dischargeline is placed on the front ofthe house, since a large deckblocked access to the bandjoist in the rear where water istypically discharged. A propri-etary IceGuard fitting allowsdischarge water to escape ifthe pipe freezes downstream.The fitting also acts as acoupling between the 2-inchpipe exiting the house and the4-inch exterior pipe.

pond in the yard.

Another option is to run an under-

ground pipe to daylight, but some home-

owners don’t want to damage their lawns

and some properties don’t have enough

slope for a daylight drain.

Finishing Touches After the pipe is run and the system

tested, we patch the concrete around the

sump, and cover the WaterGuard pipe

with at least an inch of concrete. The

only part of the pipe that’s visible is the

vertical lip that catches water running

down the wall. We also install a battery-

powered high-water alarm that alerts

the homeowner if the system is not

working properly (Figure 8). Often we

install fiberglass-reinforced panels over

the interior basement walls as a final

step. The plastic panels won’t support

mold growth, are easy to clean, and give

the basement walls a better appearance

(Figure 9).

Basement projects on small homes like

this 1,200-square-foot ranch typically

range from $1,500 to $8,000, depending

on the extras selected by the client.

Scott Anderson is the owner of Tri-State

Basement Systems in Berlin, Vt.


Figure 9. Many customers opt to finish the basementwalls with white fiberglass-reinforced panels (left), abig improvement over the moldy masonry typicallyfound in wet basements. The panels are fastenedwith drive anchors instead of adhesive, leaving spacefor seeping water to drain to the WaterGuard piping.These pictures were taken only a few days after thesump was installed. Note that the floor is completelydry (above).

Figure 8. Final steps includepatching the floor around thesump and basement perimeter(left) and installing a high-wateralarm (above) that sounds whenthe pump or discharge linemalfunctions. An emergency floordrain handles leaks — plumbingmishaps, a broken washing-machine hose, and the like.

A sloped finish

grade and properly

placed perimeter

drains will keep

the basement dry

A sloped finish

grade and properly

placed perimeter

drains will keep

the basement dry

s a concrete contractor, I have avested interest in how well the

water on site is controlled.Underground water and runoff

from rain and snow pose a threat both tothe structural integrity of the foundationsI build and to below-grade interior livingspace. Wet basements and cracked founda-tions are difficult to fix after the fact, butgood perimeter drainage, both at gradeand down at the footings, is a cheap andeasy way to prevent problems. If you fol-low these rules of thumb for perimetergrading and drain tile, you’ll sleep easyknowing that the water control systemsyou buried today won’t bubble up into acallback tomorrow.

Surface RunoffAlthough some wind-driven rain strikes

the siding and drains onto the ground,most surface runoff comes from the roof,and the amount of runoff varies accord-ing to the size and style of the roof. A

by Brent Anderson, P.E.

AFOUNDATIONDRAINAGEFOUNDATIONDRAINAGE

gable roof deposits all runoff onto the ground under theeaves, with little runoff at the gable ends; a hip roof distrib-utes the runoff more evenly on all sides (see Figure 1). Inaddition, valleys at main roof intersections and dormers canconcentrate runoff into a relatively small area on the ground.In cold climates, runoff increases significantly during springrainstorms when higher temperatures and rain combine tomelt snow on both the roof and the ground, adding to thetotal amount of surface water that must be drained awayfrom the foundation.

Sloped grade. Most basement water problems can be solvedby properly sloping the ground around the house. The finishgrade should slope away from the foundation at the rate of 1/2 to 1 inch per foot for 6 to 10 feet. A 2- to 4-inch cap ofsilty-clay material will keep runoff from percolating downthrough the backfill.

A sloped grade will not work for long, however, if the perime-ter fill is not mechanically compacted, which is rare in residen-tial construction. Instead, compaction is left to chance andoccurs slowly over a period of months or years, depending onclimate and the type of backfill used. Gravels and sands perco-

late faster and may reconsolidate more quickly — typically,from three months to a year. Silts and clays, which have a muchslower percolation rate, may not compact for several years.

In either case, however, the result is a negative grade thatdirects runoff back toward the foundation. Depending on thetype of backfill, sooner or later the runoff will overwhelm thefooting drainage system, and basement water problems willappear. Silt or clay fill, which hold water longer than gravel orsand, can make the foundation more susceptible to crackingfrom frost action; hydrostatic pressure may also develop withthese types of fill, forcing water through the slab-footing joint.Rarely will any of these problems appear immediately, butdown the road, you’ll be faced with a messy and expensiverepair job.

Gutters. While gutters can dramatically reduce the totalground area onto which roof water drains, it is crucial to usea sloped leader to extend downspouts along the ground tocarry water away from the foundation (Figure 2). Otherwise,a gutter-and-downspout system compounds the drainageproblem by concentrating the entire roof runoff load into afew small areas, usually at the house corners. Leaders should

MARCH JLC 1999

Note: Every inch of rain, whether it falls during a one-hour downpour oran all-day rain, deposits 1,500 gallons of water onto the ground around atypical 2,500-square-foot roof surface. During a winter rainstorm, everyfoot of melting snow on the roof adds an additional 1,500 gallons.

Concentratedrunoff at valleyand dormer

Less runoffat hip

Gable Roof Runoff Hip Roof Runoff

Roof Runoff(from 2500 sq. ft. roof)

Rainfall Rainfall Volume VolumeAmount Rate (cubic ft.) (gallons)

1 in. per hr. 200 1,500

1 in. per day 200 1,500

2 in. per hr. 400 3,000

2 in. per day 400 3,000

Figure 1. Both of these roofs coverapproximately 2,500 square feet. Thegable roof deposits runoff along twosides of the house; the hip roof spreadsthe runoff more or less evenly along allsides. Main roof valleys and dormersconcentrate the runoff into smaller areason the ground.

Concentratedrunoff at valleyand dormer

Roof runofffalls to groundat eaves

Less runoffat hip

MARCH JLC 1999

Downspout

Leader dischargesonto sloped ground

Finish grade slopes1/2" to 1" per foot for 10'

10'-0"

2" to 4" clay capover backfill

Downspout with Sloped Leader

Downspout with Catch Basin

Figure 2. Sloped down-spout leaders shoulddischarge at least 10feet away from thefoundation wall (top).Use solid drain pipe tocarry runoff from a con-crete catch basin todaylight or a drywell(bottom).Downspout

Filter fabric or grateto prevent clogging

24" x 24" concrete catch basinwith water-tight bottom

Solid pipe, drain todaylight or drywell

Crushedstone

Buried rigid foam aroundcatch basin (optional)

MARCH JLC 1999

Figure 3. A properly sloped con-crete or paver sidewalk will reducethe amount of runoff that perco-lates through the backfill (left).Where perimeter plantings areused to landscape, improvedrainage by burying a sheet ofpolyethylene below the plant bed,with openings cut out for roots(below). Tie shallow perforateddrain tile to solid pipe to carrywater to daylight or a drywell.

Grade min. 8"-12" below sidingto avoid splashback

Concrete or paver sidewalkcovers full width ofbackfilled area

Concrete or Paver Sidewalk

Crushed stone orwood chips

Filter fabric

Cutopeningsin poly forroots

Buried polyethylene

Perforateddrain tile

Plant Bed with Drain

discharge onto sloping ground at least 10 feet from the foun-dation. If downspouts dump directly into a catch basin on thesurface or underground, the collected runoff should be carriedthrough a solid drain pipe to a drywell or to daylight.

Keep gutters clear of leaves, pine needles, and ice. Overflowfrom blocked gutters can follow the contour of the gutter andsaturate the soffit and siding, often making its way into thewall and wetting the insulation, drywall, and floor. Similarly,gutters in cold climates can encourage ice damming, with thesame damaging results.

Hardscape. Concrete or paver block sidewalks can also con-trol percolation of runoff into the backfill (Figure 3) — I’vemeasured reductions in runoff percolation of between 300%and 500%. Again, the hardscape should be wide enough to

cover the entire backfilled area, and the surface should slopeaway from the foundation walls.

A less expensive technique is to bury a sheet of polyethylenein a plant bed. The poly should cover the backfilled founda-tion trench and slope to a perforated drain tile laid parallel tothe foundation. Use solid pipe to carry runoff to daylight or toa drywell. In landscaped areas, cut openings in the poly toaccommodate plant and tree roots.

Buried poly works well, so long as the backfill has beencompacted. With a negative grade, however, the poly actuallydirects the water into the foundation wall. Plant and treeroots near the foundation can also compound problems withuncompacted fill, because their root systems absorb waterand cause the soil to reconsolidate quickly. In a drought, tree

roots can pull so much moisture out of the soil that the foun-dation may settle.

Perimeter Footing DrainsFoundation perimeter drains work in both directions. They

not only carry rainwater percolating down through the back-fill away from the foundation, they also relieve excessivehydrostatic pressure from rising groundwater. By helping thebackfill dry out more quickly, properly installed perimeterdrains reduce lateral soil pressure, which in turn means thatfoundation walls can be designed to use more porous materi-als and less steel.

There’s a right way and a wrong way to install perimeterdrainage. Unfortunately, many foundation contractors andhome builders labor under a false sense of security, reasoningthat if complaints about leaky basements don’t surface withinthe first year or two after a project is completed, their con-struction techniques must be working. The fact of the matteris that basement water problems that occur within the firsttwelve months are usually related to waterproofing defects.Drain tile problems typically take many years to develop.Thus, many contractors have buried time bombs that willeventually blow up in their faces.

Holes DownAlthough porous cement-based tile is still in use today, most

residential contractors would agree that perforated 4-inch-diameter plastic pipe produces tighter joints and is easier towork with. Not all would agree, however, on which directionto place the holes in the pipe when installing footing drains.

The answer depends on the type of pipe. Flexible HDPE(high-density polyethylene) is slotted all the way around, andsome rigid PVC has a pattern of holes around the entire cir-

cumference. With these types of drain tile, there is no “right”direction because there are openings on all sides. Pluggedholes on the bottom are cleared by water entering through thesides and top.

The most popular drain tile, however, is rigid PVC that hasjust two parallel rows of holes close together along its length.The classic approach is to lay this type of drain tile with theholes facing down, in the five-o’clock and seven-o’clock posi-tions. This allows a rising water table to enter the pipe at itslowest point.

Filter fabric. While hydrostatic pressure helps to flush siltfrom the pipe, all buried drain tile should be surrounded withcoarse gravel or crushed stone, and wrapped with a filteringmaterial. Without a filter, silt will contaminate the stone andeventually enter and plug the holes in the pipe (Figure 4).Various geotextiles are available in rolls, and pre-wrapped or“socked” pipe — pipe that is manufactured with a filter sleevealready in place — is also available.

Drain Tile LocationFilter paper and properly oriented perforations, however,

will not guarantee that drain tile will work. The pipe must alsobe installed carefully and in the right location with respect tothe footing and any interior slab.

From a pure engineering point of view, the ideal place to layexterior drain tile is alongside the footing, because water froma rising water table enters the pipe sooner (Figure 5). The draintile does not need to be sloped, although a slight pitch helpskeep the pipe clear of silt and clay (particularly when the pipehas just two rows of holes on the bottom). Avoid trying toslope flexible drain tile, however, because you can inadver-tently create dips and sags that will eventually collect silt andclog the pipe (Figure 6). In fact, undulating drain tile can

MARCH JLC 1999

Figure 4. Without a filter to keep silt from contaminatingthe surrounding stone, drain tile can be rendered uselesswithin just a few seasons (left). Pipe that is pre-wrappedor “socked” with filter material will prevent drain tile frombecoming plugged (above).

result in premature failure of the drainage system. This prob-lem is more pronounced when trees are growing close to thefoundation, because wet silt and clay accumulating in lowspots become targets for water-seeking tree roots in dry peri-ods or in dry climates. In a relatively short period of time, treeroots can completely plug drain tile.

Some contractors create an even lower elevation for the tileby digging a small trench next to the footing. To avoid under-mining the foundation, however, most codes require that thetile be placed outside a 60-degree angle from the footing.

Drain tile can also be placed on top of the footing. Theadvantage here is that the tile will be as level as the footing —a good strategy when using flexible pipe (Figure 7). But thishigher placement doesn’t control a rising ground water tableas effectively, and may require raising the elevation of theinterior slab.

Specialty drainage products. Today there are several prod-ucts on the market, such as Form-A-Drain (CertainTeed

Corp., P.O. Box 860, Valley Forge, PA 19482; 800/233-8990;www.certainteed.com), that provide both the footing formand the drain tile (Figure 8). These systems not only ensurethat the drainage system is level, they often provide moreflow capacity than traditional pipe systems.

On sites where an exceptionally high ground water tablecreates intermittent hydrostatic pressure on the foundationwalls, dimpled sheets can be used in conjunction with stan-dard drain tile. These membrane systems provide a water-proof barrier while also directing excess ground water fromhigher up on the foundation walls into the perimeterdrains.

Discharging Collected WaterCapturing ground water in a perimeter drainage system is

only half the battle — once you’ve collected water in thedrain tile, you have to dispose of it somewhere. Dischargingwater into sanitary sewer systems is generally illegal, which

MARCH JLC 1999

Filter fabric

Drain tile min.6" below topof slab

6"

12"Minimum stonedepth around threesides of pipe

2"

Pipe at Bottom of Footing

Filter fabric


12"

12"Maintain 60°shoulder to avoidundermining footing

Pipe Below Footing

Figure 5. The best location for rigid drain tileis alongside the footing. Minimum require-ments for stone cover depend on whether thetile is flush with the top of the footing (topleft) or the bottom (above). In either case, thetop of the interior slab should be at least 6inches above the top of the drain tile. Thepipe can be laid level or pitched slightly.

Where drain tile must be located lowerthan the bottom of the footing (left), avoidundermining the footing by keeping the pipeoutside of a 60-degree angle measured fromthe corner of the footing. This location alsorequires more stone cover for the pipe.

Pipe Even with Top of Footing

Filter fabric

Stone coverextends min.6" over pipe


6"

6"6"

MARCH JLC 1999

Figure 8. Form-A-Drain stay-in-place footing forms ensure a levelperimeter drain and have a larger capacity than pipe systems(above). To control hydrostatic pressure, dimpled drainage panelsfastened against the foundation wall carry water from the backfillinto the perimeter drains (right).

Filter fabric

Top of pipe shouldnot be higherthan top of slab

12"

Flexibledrain tile(slotted)

12"

2"

Pipe Resting on Footing

Figure 7. To keep flexible drain tile fromdeveloping low spots that will collectsilt, place it on top of the footings, mak-ing sure that the top of the pipe is nothigher than the top of the interior slab.

Figure 6. Regardless of the type of pipe used or its shape, unfiltered drain tile can easily be plugged with silt and clay (left).Water-seeking roots from trees growing too near the foundation can also completely clog perimeter drains (right).

leaves two basic ways to get rid of the water: On sloped sites,you can extend unperforated drain tile to daylight and dis-charge the water on the ground; on flat sites, you can collectthe water in a sump basket and pump it to a discharge areaaway from the basement.

Gravity discharge. Two elements are critical to proper func-tion of a gravity drainage system. First, although the perforateddrain tile around the foundation itself may be level, solid piperunning from the foundation to daylight should slope at therate of 1/16- to 1/8-inch per foot. Second, the open end of thedischarge line should prevent entry by rodents, frogs, snakes,and reptiles. One method is to cover the exposed end of thepipe with 1/4-inch hardware cloth. Alternatively, you can burythe end of the pipe in crushed stone, which will allow thewater to seep out below grade.

Pumped discharge. While gravity discharge to daylight ischeap and easy, I recommend installing a sump basket as abackup. A submersible sump in the bottom of the sump bas-ket connects to a hose or rigid pipe system that carries thecollected water out of the basement. If you provide for the

collection sump at the time the foundation and slab areplaced, the pump and discharge piping can be installed laterif needed.

The sump basket should be located inside the foundation,where it can pick up ground water that rises under the slab.On a flat site where all ground water must be pumped away,water from perimeter drains should also be directed into thesump through drainage sleeves in the footing (Figure 9). Toavoid having to excavate later, be sure to place sleeves beforethe footings are poured. Use 4-inch-diameter pipe, and spacesleeves 6 to 8 feet apart around the entire perimeter of thefooting. In special cases where the slab is placed a foot or moreabove the top of the footings, you can locate sleeves in thefoundation wall. Although water passing through the sleevesor under the footing will generally find the sump basket on itsown, I recommend an interior drain pipe at the perimeter, ter-minating in the sump basket.

Brent Anderson owns and operates Brent Anderson Associates, aconcrete contracting and consulting firm in Fridley, Minn.

MARCH JLC 1999

Filter fabric Discharge collectedwater at least 10'away from foundation

Sleeve throughconcrete footing

Clay, plastic,or concretesump basket

Submersiblepump

12"

12"

Hose or rigidPVC discharge pipe

Interior draintile at perimeter

60°

Interior Sump Basket

Figure 9. An interior sumpbasket picks up excess waterflowing through sleeves inthe footing (photo). A sub-mersible pump connected toa hose or rigid pipe dis-charges the water on theground away from the foun-dation (illustration).

PM Home Page » Home Journal » How-To Central » Other Topics

Basement Blues

Untamed runoff can sink your house. Fight back. BY MERLE HENKENIUS Illustrations by Thomas Klenck Published in the April, 2005 issue.

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If you have trouble with basement water, you're not alone. We spoke with Douglas Pencille, a Minnesota housing inspector with firsthand experience. "I visit 1300 to 1500 houses per year and 30 to 40 percent of them have basement water damage. It's a big problem, often requiring corrective action." What kinds of corrective action?

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It all depends on the source of the water.

Water From Above ... The most common cause of basement water is unmanaged rain runoff. Rainwater from the roof flows down through the soil and collects at the bottom of the original foundation excavation. While the weight of the saturated earth alone can break a wall, the situation worsens when the water freezes and exerts a lateral force that can cause cracks and buckling. How do you know when water damage is from runoff? When leaks follow substantial rains and when the soil around the foundation appears settled.

The solution is a well-maintained gutter system that uses downspout extensions to carry roof runoff at least 4 ft. from the foundation wall. Also, the grade next to the wall must be sloped to direct surface water away from the house.

... And Below Groundwater problems can result from a high water table or an underground spring. Sometimes the problem is seasonal, coinciding with spring snowmelts and heavier rains, but it can occur at any time. Ground-water doesn't usually break walls, but it can flood the basement floor.

Exterior draintiles around the perimeter of the foundation footing are the first line of defense against groundwater. The simplest retrofit solution is to install a sump pump that carries the water away from the house. An interior draintile system is effective in routing water from the entire basement to the sump.

For background information on how house construction works, click here

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Basement Blues


Previous 1 2 3 Next Foundation Repairs: If your foundation walls have cracks or they've buckled, you can do much of the repair work yourself or hire a contractor to handle the job. The newer techniques that use high-tech materials and sophisticated hardware require specialized skills so you'll need to hire a professional.

Traditional Fixes

WALL REBUILD One solution to a buckled block wall is to replace it. You can do this without excavating. First, use post jacks and a 4 x 6 beam to take the load from the wall. Then, remove the damaged section down to the footing. After rebuilding the wall, wait several days before removing the jacks.

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EXCAVATION AND REPAIR To keep the original wall, excavate the area outside. Then, use a jack and a few wooden beams to nudge the wall back into position. Repair any bad mortar joints, and consider improving your drainage system to reduce hydrostatic pressure and to direct water away from the house.

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WALL BRACING If you don't want to replace the wall or excavate, try bracing. Vertical steel I-beams set in holes in the floor and fastened to steel braces at the ceiling joists can keep a wall in place. Local building codes vary, though, so make sure this approach is approved in your area.

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Basement Blues


Previous 1 2 3 Modern Approaches

BRACING WITH BELTS This system replaces I-beams with carbon-fiber/Kevlar belts (Fortress Stabilization Systems, 800-207-6204; www.fortressstabilization.com). A contractor grinds 1/8-in. recesses across the cracks. The belts are coated with epoxy and set in place, and the epoxy is trimmed flush with the wall.

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WALL-ANCHOR REPAIR Wall anchors (Grip-Tite Manufacturing, 515-462-1313; www.griptite.com) consist of two steel plates, one located on the inside of the wall and the other buried in the ground outside, and a threaded rod connecting the plates. Tightening a nut on the rod draws the wall flat.

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LIFTING WALLS When footings settle they can be repositioned with push piers (Foundation Pier System, Grip-Tite Manufacturing). Hydraulic drivers placed around 3 to 6 ft. apart push steel piers down to the bedrock while support brackets restore the footing to its original level.

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When you live on a barrier island,

just keeping your little piece of

real estate from washing away is a con-

stant struggle. Fred Sprinkle, a foundation

and excavation contractor on Dauphin

Island, Ala., frequently uses vinyl sheet pil-

ings to keep the ground beneath his

clients’ homes from ending up in the Gulf

of Mexico.

His employees — who spend as much

time in the water as they do on land, and

dress accordingly — start one of their

vinyl seawalls by building a frame of pres-

sure-treated wood pilings and dimen-

sional lumber (1). The lumber and pilings

are CCA-treated; newer pressure-treating

formulas don’t hold up as well in salt-

water and aren’t as resistant to marine-

boring organisms.

SEPTEMBER 2006 I JLC I 1

On the Job

Installing Sheet Piles

1

2

Once the frame is assembled, the crew

ties it to dry ground with stainless-steel

threaded rods and earth anchors (2, pre-

vious page).

Next, workers use a gas-powered pump

(3) to wash holes in the sea floor for the

12-inch-wide piles. The pump sends

water first through a 2-inch hose and

then through a 11⁄2-inch steel pipe (4);

the transition from a larger to a smaller

diameter increases head pressure. The

pipe’s weight makes controlling and

directing the stream of water easier.

Once the holes are made, the crew

pushes the 12-foot-long sheet pilings in;

some piles go easy, and others require

persuasion with a sledge or a small pneu-

matic jackhammer (5). All have mating

edges that lock them together (6, page

48). They’re nailed to the wood frame at

the top and at the water line.

The walls’ integrity depends on how

deep the pilings are placed in the sand.

On the Job l Installing Sheet Piles

3

4

5


The day I visited, workers were replacing

a poorly built wall with one that went

about twice as deep.

Unscrupulous contractors often use

shorter pilings to save time and money,

but occasionally even competent install-

ers face an obstacle that makes it impos-

sible to drive the pilings to their intended

depth.

When Sprinkle’s employees run into

this problem, they try to remove the

obstacle any way they can. Sometimes

they keep enlarging the hole till they can

pull the object out by hand; other times

they lug it out with a chain connected to

their excavator or backhoe (7). Only as a

last resort do they cut the pile shorter.

Once all the piles are installed, the area

is backfilled with sand and the wall is fin-

ished with a pressure-treated cap.

This kind of work may sound like a day

at the beach, but crew members told me

cuts and puncture wounds on hands and

feet — plus nasty sunburns — are com-

mon. They also said that despite the large

retrieval magnet kept permanently in the

truck, they lose hammers and other hand

tools regularly. — Patrick McCombe


On the Job l Sheet Piles 6

7

Installation Guide

RR

www.hardiepipe.com

This Installation Guide is offered to provide you guidance inthe proper unloading, handling, and installation of Hardie® Pipe.

Hardie Pipe, a division of James Hardie® Building Products,Inc., is The Next Generation of Concrete Pipe. It is importantthat proper handling and installation procedures are followedto ensure a long-lasting, trouble-free concrete pipeline.

Please contact our Customer Service Department toll-free at877-910-3727 from 7AM to 5PM EST, Monday through Fridaywith any questions or comments you may have about thehandling or installation of Hardie Pipe as it pertains to yourproject.

The information contained in this booklet is based on fieldexperience and sound engineering judgment in accordancewith standard concrete pipe installation practices as found inASTM C1479. It should in no way be used to override or deviate from the specifications and/or engineering drawingsprovided for your specific project.

Ordering Procedures & Customer Support

Hardie® Pipe Arrives on the Jobsite

Unloading Hardie Pipe from Flatbed Truck

Storing Hardie Pipe on the Jobsite

Handling Hardie Pipe

Preparing the Pipe Trench

BeddingHaunchLower SideOverfill ZoneExcavation LimitsDewateringStandard Installations

Jointing

Installing Gaskets & Applying LubeMaking the Pipe Joint

Minimum Cover for Construction Loads

Connecting Hardie Pipe to Structure/Manhole

Field Cutting Hardie Pipe

Hardie Pipe Warranty

Appendix

Hardie Pipe Field Repair Procedures

Cracked or Chipped JointPuncture HolesSurface ImperfectionsGouging

Bundling Standards Pipe Nominal Weight Chart Shipping Specifications Nominal Pipe OD’s Joint Gap TolerancesCenter Stripe Color Code

Table of Contents

3

4

5

6

8

9

11

13141414151516

19

1921

24

25

26

29

30

30

30313334

353839404142

Ordering Procedures & Customer Support

Coordination between the contractor, supplier and engineer isrecommended to avoid mistakes and possible delays in pipedeliveries. Although Hardie® Pipe stocks a wide range of pipesizes and classes, it is important to follow proper lead time procedures provided by the Customer Service Department.Hardie Pipe maintains an experienced staff to help youachieve the most cost and time-efficient installation. Our professional team is available to provide guidance aboutHardie Pipe.

To initiate a pipe order, please contact your local representative or the Hardie Pipe Customer ServiceDepartment at 877-910-3727.

4

5

Hardie® Pipe Arrives on the Jobsite

Always confirm pipe shipment with bill of lading Before Signing:

If there are any discrepancies on the bill of lading, contact

the Hardie® Pipe Customer Service Department

(877-910-3727) between the hours of 7AM and 5PM EST,

Monday through Friday.

√ Jobsite/Project√ Pipe Quantity√ Pipe Class√ Pipe Diameter

√ Quantity of Gaskets (Normal or Oil Resistant)

√ Lube√ Certification Stamp

(if applicable)

Figure 1 - Hardie Pipe Arriving at Jobsite

6

Unloading Hardie® Pipe from Flatbed Truck

Coordinate delivery and unloading with the constructionschedule to avoid re-handling and unnecessary equipmentmovement. It is the responsibility of the contractor to ensurethat Hardie® Pipe delivery trucks have full access to theunloading area.

For ease in shipping and offloading, Hardie Pipe is bundledand banded together in standard quantities as listed in theAppendix in Table 5 and loaded on flatbed trucks as listed inTable 7.

Caution: Consult Nominal Pipe Weight Chart (Table 2) and

Confirm Proper Equipment Used for Unloading Hardie Pipe.

Hardie Pipe is longer than traditional steel reinforced concretepipe. It is important to center the load on your equipmentbefore the pipe is lifted off the truck. Follow the manufactur-er’s guidelines and safety procedures for the specific piece ofequipment used to unload the pipe.

Figure 2 - Never Roll Hardie Pipe off the truck!

7

Use of a forklift is recommended when offloading Hardie® Pipe. Depending upon equipment, fork extensionsmay be used if designed to properly support the load of thepipe bundle.

Note: Please consult Nominal Pipe Weight Chart Table 6 of

the Appendix

Align Forks on pipe as shown in the picture above and placeHardie Pipe on ground as appropriate.

Hardie Pipe does not recommend cutting the steel bands

bundling the pipe together until safely stored on the jobsite.

However, if it is necessary to cut the bands while on the

truck, please take safety precautions to stabilize the pipe on

the pallet AND the remaining pipe on the truck.

Contact your local sales representative or Hardie PipeCustomer Service Department if you are not sure aboutoffloading procedures.

Figure 3 - Forklift With Pipe Bundle Centered Over Forks

Storing Hardie® Pipe on the Jobsite

Hardie® Pipe should be stored properly on your jobsite to prevent unnecessary damage to the pipe and gaskets.

Be sure to keep stored gaskets out of direct contact with sunlight to prevent the rubber from experiencing UV damage.

Storage area must be a level area with a stable base.

Hardie Pipe may be stored on site as shown in the diagramabove. Pallets of pipe may be stacked up to 8-feet high if thefollowing conditions are met:

� Pipe must be aligned in the same direction.� Pallets must be aligned in the same direction.� Pallets must be centered on the lower bundle.� No cantilever pipe or pallets are allowed.

8

Figure 4 - Proper Storage of Hardie Pipe Figure 5 - Improper Storage of Hardie Pipe

9

Handling Hardie® Pipe

Hardie® Pipe should be picked up and handled using properlyrated rigging equipment capable of lifting appropriate load(See Table 6 of the Appendix).

Care should be taken to insure that the pipe ends are notdamaged and worker safety is maintained while maneuveringHardie Pipe around the jobsite and setting Hardie Pipe into the trench. Pipe should be carried level to avoid damagingjoints. A center stripe is painted on the pipe during manufacturing to aid in locating the center of the load. Thecolor of the stripe designates the class of the pipe (See Table 10 in the appendix).

It is the responsibility of the contractor to locate the true cen-ter of the pipe for lifting and to handle loads safely.

Align rigging along center stripe as shown in picture below:

When picking up Hardie Pipe,use worker or tether line toguide end of pipe.

Caution: As Hardie Pipeis Lifted and Moved,Watch for “Pinch Points.”

Do not lift

Hardie Pipe

off set from the

center stripe

Figure 6 - Recommended Lifting and Handling

Figure 7 - Improper Lifting and Handling

10

Do not lift

pipe with

forks

inside pipe

Do not lift pipe

with slings

inside pipe.

If damage occurs to the pipe while handling, consult the field repair procedures in the appendix of thisinstallation booklet. If bell or spigot is damaged beyondrepair, cut the damaged section of pipe back to sound, solidmaterial and use this undamaged piece to come into or out ofa manhole/junction box.

Figure 8 - Improper Lifting

Figure 9 - Improper Lifting

11

Preparing the Pipe Trench

Hardie® Pipe is a concrete pipe that should be installed inaccordance with ASTM C1479. See Table 8 of the appendix forOD’s by diameter and pipe class.

When preparing the pipe trench, care should be taken toassure that the foundation is free of rock, hard, lumpy, orother unyielding material. The foundation shall be moderatelyfirm to hard in situ soil, stabilized soil, or compacted fill material. Remove muck or other soft material to a depth necessary to establish a firm foundation. If the trench isundercut to remove undesirable foundation material, theundercut area must be filled and compacted to the level of thebedding zone of the pipe. Backfill undercut areas withapproved materials compacted to at least the same density asthe bedding material.

Trench grades should be monitored to assure compliance withspecified grade. Failure to maintain proper grade can result inhigh and low spots in the pipeline, which can affect thehydraulic capacity of the line as well as prevent proper bedding of the pipe.

Figure 10 - Pipe / Installation Terminology

12

Figure 11 - Standard Trench Installation

Figure 12 - Embankment Installation

13

Bedding

Uniformly construct bedding over the entire length of the pipebarrel, near structures, to distribute the load-bearing reactionevenly to the bedding over the full length of the pipe barreland to maintain the required pipe grade. Bedding under themiddle third of the pipe diameter shall be loosely placed, anduncompacted prior to placement of the pipe. Any outer bedding shall be compacted to the requirements for the specific Standard Installation type.

Do not make adjustment in grade by lifting and dropping thepipe, by pushing down on pipe with excavating equipment orby lifting the pipe and packing bedding material beneath thepipe. Pipe not on grade shall be completely removed, thegrade corrected and the pipe rejoined.

Note: Ensure that bedding is free of rock, hard, lumpy or

other unyielding material.

Figure 13 - Pipe Bedding and Foundation

14

Haunch

Construct the haunch using the specified soil type and compaction level required for the designated installation.Haunch material shall be placed and compacted uniformly overthe entire length of the pipe barrel, near structures, to distribute the load-bearing reaction evenly to the bedding overthe full length of the pipe barrel. Maximum aggregate sizeused in the haunch area shall not be greater than 1-inch.Compact uniformly placed soil on either side of the pipe to thespecified density to prevent lateral displacement of the pipe.

Lower Side

Soil placed in the lower side shall not contain debris, organicmatter, frozen materials or large stones with diameters greaterthan one half the thickness of the compacted layer beingplaced. The lower side shall be constructed using a specifiedsoil type and minimum compaction level. When placed in layers, the layers shall be of a thickness required to achieve thespecified compaction as required by the project specifications.

Overfill Zone

Soil placed in the overfill area shall be material conforming tothe project specifications. This material shall contain no debris,organic matter, frozen materials or large stones with diametersgreater than one half the thickness of the compacted layerbeing placed. When placed in layers, the layers shall be of athickness required to achieve the specified compaction and asrequired by the project specifications. To prevent lateral displacement of the pipe, place and compact soil uniformly oneither side of the pipe to the specified density. The overfillplaced within one outside diameter of the pipe, that is abovethe spring line, and below top of the pipe, shall be compactedto at least the same density as the majority of the overfillabove the pipe. Take care not to damage pipe when usingimpact or vibratory equipment to compact soils in pipe trench.

Do not allow heavy construction or compaction equipment tocross over pipe until backfill is compacted to an elevation of atleast 3 feet above the crown of the pipe.

15

Excavation Limits

Trench width and depth directly affect the backfill load transmitted to the pipe. The pipe class specified is determinedbased upon the trench width and depth assumed duringdesign. To avoid overloading the pipe, the trench width shouldnot exceed that which is stated on the project plans and specifications without consulting with the design engineer.

Dewatering

Backfill should be placed in the dry. Dewater trench to providedry conditions during excavation and installation.

Where dewatering by normal pumping methods is ineffective,uniform bedding of a select granular material shall be placedthroughout the entire run of pipe. Uniformly construct bedding over the entire length of the pipe barrel, includingnear structures, to distribute the load-bearing reaction evenlyto the bedding over the full length of the pipe barrel and tomaintain the required pipe grade.

16

Standard Installations

Hardie® Pipe is a concrete pipe that should be installed inaccordance with the Standard Installations as shown in ASTM C1479. These standard installations are listed below.TABLE 1 - SOILS AND MINIMUM COMPACTION REQUIREMENTSInstallation

TypeBedding Thickness Haunch and

Outer BeddingLower Side

Type 1 Do/24 minimum, notless than 3” (75mm). Ifrock foundation, useDo/12 minimum, notless than 6” (150mm)

95% CAT I 90% CAT I,95% CAT II,

or100% CAT III


90% CAT Ior

95% CAT II

85% CAT I,90% CAT II,

or95% CAT III



or95% CAT III


or95% CAT III

Type 4 No bedding required,except if rock

foundation, use Do/12minimum, not less than

6” (150mm)

No compactionrequired, except ifCAT III, use 85%

CAT III

No compactionrequired, except ofCAT III, use 85%

CAT III

NOTES:1. Compaction and soil symbols -i.e. “95% CAT I” refer to CAT 1 soil materials with a minimum standard proctor compaction of 95%.2. Soil in the outerbedding, haunch, and lower side zones, except with Do/3 from the pipe springline, shall be compacted to at least the same compaction as the majority of the soil in theoverfill zone.3.SUBTRENCHES3.1 A subtrench is defined as a trench with its top below finished grade by more than 0.1H or, forroadways, its top is at an elevation lower than 1’ (0.3m) below the bottom of the paved basematerial.3.2 The minimum width of a subtrench shall be 1.33 Do, or wider if required for adequate space toattain the specified compaction in the haunch and bedding zones.3.3 For subtrenches with walls of natural soil, any portion of the lower side zone in the subtrench wall shall be at least as fim as equivalent soil placed to the compaction requirementsspecifiedfor the lower side zone and as firm as the majority of soil in the overfill zone, or shall beremoved and replaced with soil compacted to the specified level.

17

Table 2 - SOILS AND MINIMUM COMPACTION REQUIREMENTSInstallation

TypeBedding Thickness Haunch and

Outer BeddingLower Side


95% CAT I 90% CAT I,95% CAT II,

or100% CAT III


90% CAT Ior

95% CAT II


or95% CAT III



or95% CAT III


or95% CAT III

Type 4 No bedding required,except if rock founda-tion, use Do/12 mini-mum, not less than 6”

(150mm)

No compactionrequired, except ifCAT III, use 85%

CAT III

No compactionrequired, except ofCAT III, use 85%

CAT III

NOTES:1. Compaction and soil symbols -i.e. “95% CAT I” refer to CAT 1 soil materials with a minimum standard proctor compaction of 95%. 2. The trench top elevation shall be no lower than 0.1H below finished gradeor, for roadways, its topshall be no lower than an elevation of 1’ (0.3) below the bottom of he pavement base material.3. Soil in bedding and haunch zones shall be compacted to at least the same compaction as specified for the majority of soil in the backfill zone.4. The trench width shall be wider than shown if required for adequate space to attain the specifiedcompaction in the haunch and bedding zones.5. For trench walls that are within 10 degrees of vertical, the compaction or firmness of the soil inthe trench walls and lower side zone need not be considered.6. For trench walls with greater than 10 degree slopes that consist of embankment, the lower sideshall be compacted to at least the same compaction as specified for the soil in the backfill zone.

18

TABLE 3 - SOIL DESIGNATIONSSIDD Soil Representative Soil Types Percent Compaction

USCS AASHTO StandardProctor

ModifiedProctor

Gravelly Sand(CATI)

SW, SPGW, GP

A1, A3 1009590858061

959085807559

Sandy Silt(CAT II)

GM, SM, MLAlso GC, SCwith less than20% passing#200 sieve

A2, A4 1009590858049

959085807546

Silty Clay (CAT III)

CL, MHGC, SC

A5, A6 1009590858045

100959045

908580757040

90858040

19

Jointing

Installing Gaskets and Applying Lube

Carefully clean all dirt and foreign substances from the jointing surfaces of the bell and spigot end of Hardie® Pipe,including the gasket groove. Gaskets should not be placed onHardie Pipe until pipe is ready to be installed. Confirm thatgasket diameter matches pipe diameter. Install gasket onspigot end of pipe in the machined gasket groove and oriented in the proper direction as illustrated below:

Caution: Be sure that

gasket is seated

properly in machined

gasket groove and

free of any soil,

twists, or abrasions to

insure proper joint

seal is made.

Figure 14 - Properly Seated Gasket

Figure 15 - Improperly Seated Gasket

After gasket is in place, generously apply lube to Hardie® PipeBELL END ONLY as shown below:

Be sure to apply a generous amount of lube along the entiresurface of the pipe bell to allow for easy installation.

Note: For wet conditions use a subaqueous lube.

Figure 16 - Lubrication of Bell

20

Figure 17 - Lubrication of Spigot

21

Making the Pipe Joint

Proper safety measures should be implemented when working in trenches and confined spaces in accordance withjobsite safety instructions.

Before laying Hardie® Pipe into the pipe trench, be sure thatbedding material is set to proper line and grade.

Lower Hardie Pipe into trench. Hardie Pipe can be laid ineither direction as long as care is taken to put the jointtogether properly and keep debris out of the joint duringassembly. It is preferred to face the bell end of pipe in thedirection that the pipe is being laid to prevent bedding material from entering the bell during jointing.

When assembling pipe, take care to ensure that workers keephands and clothing clear of joint to prevent injury.

Figure 18 - Proper Line and Grade of Trench

Figure 19- Strapping and Pipe Guidance

22

Join pipe by inserting the spigot into the bell end at as smallof an angle as possible, starting at the top of the pipe, asshow in the detail below.

Note: By doing this you prevent rolling of gasket.

Lower pipe to grade and insert remainder of spigot into thebell. Bring pipe home by pulling the cable or strap as shownin the details below.

Figure 20 - Joining of Pipe

Figure 21 - Bringing Pipe Home

Avoid the use of excavating equipment to push pipe sectionstogether. This can damage the pipe.

Check for proper line and grade. If pipe grade needs to beraised, Hardie® Pipe recommends removing the pipe from thetrench and regrade full length of bedding. Lifting up pipe andshoveling dirt/bedding material under the pipe will leavevoids and is NOT acceptable.

If pipe grade needs to be lowered, Hardie Pipe recommendsremoving pipe from the ditch and correct the grade.

Note: Maintain minimum bedding thickness

Figure 22 - Improper Homing of Pipe

23

Figure 23 - Improperly Bringing Pipe to Line and Grade

24

Once the pipe is set to proper grade, confirm that the gasket hasnot rolled and is not exposed at the joint.

Check with Table 9 of the appendix to confirm the joint gap onthe outside of the pipe is within tolerance.

The remaining backfill material should be placed and com-pacted around the pipe in accordance with project plans andspecifications.

To insure that the pipe does not move when installing thenext section of pipe, uniformly place and compact soil oneach side of the pipe to the specified density to prevent lateraldisplacement of pipe.

Minimum Cover for Construction Loads

Do not allow heavy construction or compaction equipment tocross over culvert or storm sewer pipes until placing andcompacting backfill material to the finished earthwork gradeor to an elevation at least 3-feet above the crown of the pipe,or as noted in project specifications.

Figure 24 - Improperly Seated Gasket

Connecting Hardie® Pipe to Structure/ Manhole

When pipe run comes within one section of the pipe to structure interface, take measurement to determine exactlength of pipe needed to finish the run.

Refer to Table 8 to confirm that the proper sized pipe to structure interface opening has been provided.

Cut length of pipe to the measurement taken above followingthe Field Cutting Hardie® Pipe section of this guide.

Connect pipe to the structure in accordance with engineer’splans and specifications.

Helpful Hint: Hardie ®Pipe outside diameters are smaller than

steel RCP outside diameters allowing for a smaller hole to be

cast into the concrete structure. Consult structure

manufacturer to confirm size of structure opening.

Figure 25 - Pipe to Structure Detail

25

26

Differential settlement between the structure or manhole andthe pipe may result in damage to the pipe. Therefore, it isimportant to install the structure or manhole on a solid foundation to eliminate settlement. When connecting HardiePipe to a structure or manhole, it is necessary to construct auniform bedding over the entire length of the pipe barrel todistribute the load-bearing reaction evenly to the beddingover the full length of the pipe barrel. Suspending the pipeover a void created by the excavation around the structurewhile the pipe is grouted into the side of the structure is notrecommended since uniform support to the pipe is not beingprovided. This lack of support around a structure can result indamage to the pipe. After the structure is set, backfill shouldbe brought up to the invert of the pipe, and then the pipeshould be connected to the structure.

Note: If there is a possibility of differential settlement

between structure and pipe consult with Hardie Pipe.

Field Cutting Hardie® Pipe

Use a cutting device capable of cutting reinforced concreteproducts.

Use appropriate safety precautions when operating saw/bladein accordance with manufacturers recommended practices.

Helpful Hint: For quick results, use a diamond tipped blade to cutpipe when using a powered saw.

1. Mark a cut line on the outside of the pipe.2. Make sure pipe is stable before cutting.3. Cut length of pipe to the cut line marked.4. When cutting a length of pipe, it will be

necessary to roll the pipe to get access to the entire circumference. After rolling make sure pipe is stable before resuming cutting. Hardie Pipe recommends pipe be chocked.

27

Proper safety gear must be worn to protect operator in accordance with applicable safety standards.

Cutting of Hardie® Pipe can produce dust that can be harmfulif exposed to excessive amounts over an extended period oftime. Hardie Pipe recommends that the pipe be cut as followsto help reduce dust exposure levels:

1. When using a powered saw, use saw blades specifically designed for reducing dust generation, such as a low-tooth count blade with polycrystalline diamond-tipped teeth.

2. If using a powered saw, Hardie Pipe recommends using a saw equipped with an effective dust collection or suppression system.

3. Hardie Pipe recommends that cutting occur only in well-ventilated areas, such as open, outdoor environments.

Figure 26 - Cutting Pipe Figure 27 - Improper Cutting(Hammer & Chisel)

28

Hardie® Pipe does not recommend cutting in indoor or otherwise poorly-ventilated areas, does not recommend usinga dry continuous rim diamond-edged blade when using apower saw, and does not recommend dry sweeping of pipedebris.

If exposures exceed the Occupational Safety and HealthAdministration (OSHA) Permissible Exposure Limit (PEL),NIOSH-certified respiratory protection must be worn. If uncertain about the appropriate respiratory protection orexposures, consult a qualified industrial hygienist.

Warning: AVOID BREATHING SILICA DUST. Hardie Pipe

contains silica. Inhalation of respirable silica dust can cause

silicosis, a potentially disabling lung disease, and is known to

the State of California to cause cancer. When drilling, cutting

or abrading Hardie Pipe during installation or handling: (1)

Work outdoors where feasible, otherwise use mechanical

ventilation, (2) Wear a dust mask or, if dust may exceed PEL

use NIOSH approved respirator, (3) Warn others in area. For

further information, refer to Material Safety Data Sheet or

contact manufacturer by calling 1-877-910-3727.

29

Hardie Pipe Warranty

Hardie® Pipe warrants that its goods are free from manufacturing defects for a period of one year. If any of itsgoods are proven to be defective, Hardie Pipe will, at its soleoption, either supply replacement goods or reimburse thebuyer for the purchase price the buyer paid. Whether abuyer's claims are based on negligence, breach of any impliedwarranty, strict liability, or any other theory at law or in equity,this remedy shall be buyer's sole and exclusive remedy.Hardie Pipe is not liable for any indirect, consequential, economic, loss profits, punitive or exemplary damages of anytype, under any circumstances, including those resulting fromany manufacturing defect. Submit claims to Hardie Pipe, inwriting, within thirty (30) days from date of discovery. State orfederal laws may provide the buyer with rights in addition tothose in this warranty that cannot be modified or excluded.

The recommendations in Hardie Pipe literature (e.g.brochures,printed instructions, etc.), or on its website represent goodbuilding practices. However, they are not intended to be anexhaustive statement of all the relevant data, nor are they (or any oral statements made by Hardie Pipe) intended to augment, modify and/or change the terms of this expressedwarranty. The terms of this warranty can only be made byHardie Pipe in writing. Further, there are many factors outsideof Hardie Pipe's control (e.g. quality of workmanship, particular design, detail requirements, etc). Hardie Pipe is neither responsible nor liable for any installation, application,or specification factors or decisions made by the buyer, oranyone or any entity acting on the buyer's behalf, which mayaffect the quality of its goods, the success of any project, orthe suitability of its goods to achieve a particular purpose.

To this extent, Hardie disclaims all other warranties, expressor implied, including any implied warranties of merchantability or fitness for a particular purpose, or anyother implied warranties that may be imposed by virtue of theUniform Commercial Code.

30

Appendix

Hardie® Pipe Field Repair Procedures

If minor damage to Hardie® Pipe occurs during handling orinstallation, repairs can be made in accordance with the following procedures or in accordance with engineer’s plansand specifications.

Standardized methods for repairing Hardie Pipe are presentedto ensure that all surfaces of near contact of the jointed pipesare free from chipped or spalled concrete and other suchdefects. Pipes showing minor manufacturing imperfectionshandling injuries to the bell and spigot, or pipe barrel damagemay be repaired using methods described below.

Case 1 - Cracking or Chipping of the Joint

Cracking or chipping that does not affect the sealing area ofthe joint may be repaired if the affected area meets the following conditions:

The chipping or cracking does not affect the ring groove.

Cracking may not propagate through the joint wall.

The circumferential length of a single area to be repaired shallnot exceed one fourth of the inside diameter of the pipe or thecircumferential length of several areas combined does notexceed one half of the inside diameter of the pipe.

The repair does not reduce the clearance between the bell andspigot sealing surfaces compromising the flexibility of the joint.

31

Procedure

1. Clean the area of all dirt and excess material.

2. Allow the area to dry

3. Apply an epoxy compound suitable for repairing spalledareas on concrete structures as approved by the DOT.

4. Allow epoxy to fully dry

5. Sand and smooth the repaired area to the proper joint specifications

Note: Repair should not be attempted if there is any loss ofmaterial extending into the gasket groove area. If the bell orspigot is beyond repair, cut the damaged section back tosound, solid material and use this undamaged section of pipeto come into or out of a structure.

Case 2 - Puncture Holes

Punctures holes may be repaired if no larger than sizes listedbelow:

The size of the hole is measured after the hole has been cutback to sound material.

There are two approved methods of repair, either by applyinga saddle patch or saddle plug.

Table 4 - Puncture Hole LimitsPipe

Diameter(Inches)

Puncture HoleSize Max.(Inches)

12 4

15 4

18 6

24 6

30 6

36 6

32

Procedure A – Saddle Patch

To apply a saddle patch follow these guidelines:

� Remove damaged material from the affected area and cut back to sound material then sand smooth.

� Measure the hole.

� Using a pipe with an inside diameter as close as possible to the outside diameter of the pipe being repaired, cut a blank saddle approximately 2/3 larger than the hole.

� Clean the saddle and area to be covered of all dirt and debris.

� Apply a DOT approved epoxy resin adhesive for bonding hardened concrete to hardenedconcrete.

� Place the saddle over hole and secure in place while epoxy cures.

Procedure B – Saddle and Plug

To apply a saddle and plug which gives you an internal flushfinish following these guidelines:

� Remove damaged material from the affected area and cut back to sound material then sand smooth.

� Measure the hole.

� From the identical size and class pipe, make a plug approximately 1/4–inch smaller than the hole.

� Using a pipe with an inside diameter as close as possible to the outside diameter of the pipe being repaired, cut a blank saddle approximately 2/3 larger than the hole.

33

� Epoxy the plug to the inside of the saddle using a DOT approved epoxy resin adhesive, for bonding hardened concrete to hardened concrete.

� Clean the saddle and area to be covered of all dirt and debris.

� Make sure the saddle and area to be covered are dry.

� Epoxy around the edges of the plug and fit into hole.

� Secure in place until epoxy cures.

Case 3 - Surface Imperfections

Surface layer roughness may be repaired, providing that thefollowing criteria are met:

The imperfection does not exceed 10% of the pipe wall thickness.

The area to be repaired does not exceed 10% of the total pipesurface area.

Procedure

� Use mechanical grinding equipment. Grind at least 1” past the edges of the unaffected area surrounding the repair.

� Fill area with a coating of a DOT approvedepoxy designed for repairing spalled areas on concrete structures.

� Work should be performed outdoors, wearing and usingproper safety equipment. Inform others in the area of the grinding operation.

34

Case 4 - Gouging

Gouging that does not exceed 20% of the wall thickness maybe repaired. There is no limit to the length of the affectedarea.

Procedure

1. Sand the affected area smooth.

2. Clean all dust and debris from gouged area.

3. Fill gouge with a coating of a DOT approved epoxydesigned for repairing spalled areas on concrete structures.

4. Allow epoxy to cure.

NOTE: Cracking that occurs along the length of the pipeis not permitted to be repaired.

Table 5: Bundling Standards by Diameter & Pipe Class

Hardie Pipe is crated as in the followingdrawings:

90” Dunnage with banding

12” Diameter Pipe

Minimum 84” Fork

Length Required


15” Diameter Pipe

Minimum 81” Fork

Length Required

35

36


18” Diameter Pipe


24” Diameter Pipe

Minimum 73” Fork

Length Required

Minimum 71” Fork

Length Required

37


30” Diameter Pipe


36” Diameter Pipe

Minimum 87” Fork

Length Required

Minimum 80” Fork

Length Required

Table 6: Pipe Nominal Weight Chart

CLASS AND SIZE COMPARISON

PIPEDIAMETER

(inches)CLASS

HARDIE PIPECONCRETE PIPE

NOMINAL WEIGHTPER FOOT (LBS)

STEEL REINFORCED CONCRETE PIPE

NOMINAL WEIGHTPER FOOT (LBS)

12III

IV

V

26

32

40

120

120

120

15III

IV

V

40

53

63

155

155

155

18III

IV

V

58

72

91

175

175

175

24I

II

III

IV

V

77

87

103

128

161

290

290

290

290

290

30I

II

III

IV

V

120

136

160

200

252

410

410

410

410

410

36I

II

III

IV

V

173

196

231

287

362

563

563

563

563

563

38

Table 7: Shipping Specifications

SHIPPING SPECIFICATIONS

PRODUCTCODE

SIZE(CLASS III)

INSIDEDIAMETER

(IN)

PIPES PERTRUCK

PIPES PER PALLET

FT PER LOAD

(16’ LGTHS)

112500 12” 12.0 60 6 960

115400 15” 15.0 45 5 720

118300 18” 18.0 40 4 640

124300 24” 24.0 24 3 384

130300 30” 30.0 15 3 240

136300 36” 36.0 10 2 160

39

40

HARDIE PIPE ODs

Pipe Diameter Class OD

12”III 13.77

IV 14.18

V 14.70

15”III 17.22

IV 17.73

V 18.37

18”III 20.67

IV 21.27

V 22.05

24”

I 26.72

II 27.05

III 27.56

IV 28.36

V 29.39

30”

I 33.39

II 33.81

III 34.45

IV 35.45

V 36.74

36”

I 40.07

II 40.57

III 41.33

IV 42.54

V 44.09

Table 8: Nominal Pipe ODs

Table 9: Joint Gap Tolerances

HARDIE PIPE GAP ALLOWANCES

PIPEDIAMETER

GAP ALLOWANCE(mm)

GAP ALLOWANCE(in)

12 9 3/8

15 12 1/2

18 12 1/2

24 20 3/4

30 25 1

36 25 1

41

42

Table 10: Color Code of Center Stripe for Pipe Classes

PIPE CLASS CENTER STRIPE COLOR

1 Orange

2 Blue

3 Black

4 Yellow

5 Red

Customer Service: 1-877-910-3727

Customer Service Fax: 1-866-329-3727

Customer Service Email: [email protected]

www.hardiepipe.com

RR

© 2004 James Hardie Building Products, Inc. All Rights Reserved. Printed in the U.S.A.

™,® and © denote trademarks and are copyrights owned by James Hardie Research Pty Limited ACN 066 114 092.

With all of the rain Clark County receives, managing rainwater runoff can be a

challenge. Installing and/or properly maintaining gutters on your house and outbuildings provides a simple and effective measure of collecting and

diverting rainwater, reducing mud and keeping clean water clean (see the fact sheet

Managing Roof Runoff).

What can be done with all of the water collected in those gutters? And how do you manage rain that lands on your pastures and other areas? Water flowing across pastures, turnouts and dry lots, arenas and other areas can pick up particles of sediment and manure. Nutrients attach to sediment particles and can be transported to nearby waterbodies where they can negatively impact stream health and fish and wildlife. Runoff may also cause erosion and create mud, which can affect the health of your animals and your land. Runoff collecting around foundations of barns and other buildings causes significant damage over time. Several methods are available to collect and divert rainwater before it reaches pastures, turnouts and buildings reduces mud and standing water, and limits erosion and property damage including french drains, berms, grassy swales or dry wells.

French Drains

As illustrated in Figure 1, french drains intercept water flowing across a slope. They are shallow trenches lined with weed cloth or geotextile fabric, with a perforated plastic pipe surrounded by gravel. The weed cloth is wrapped over the top of the gravel and then covered with soil. The weed cloth prevents soil from filling in the spaces between gravel, maintaining water flow through the gravel. To facilitate water flow, the trench should be sloped between 0.5% and 1%. For example, for every 100 feet in distance, a one foot drop in elevation would provide a 1% slope.

French drains can be used to collect runoff flowing down a slope or from a gutter system

and divert the water around a feature such as a building, turnout, driveway or arena. Rainwater from a single roof can be collected in gutters and the buried downspouts connected to a

Keeping Clean Water Clean and Reducing Mud

Improving Drainage

Small Acr eage P rogram

Figure 1: Cross Section of Typcial French Drain

(Doug Stienbarger, 1995)

Aggregate fill

Existing Ground

Geotextile or Weed Cloth

4 inch perforated PVC / Corrugate Plastic drain pipe

1

http://clark.wsu.edu/horticulture/smallFarmProgram/roof-runoff.pdf

Keeping Clean Water Clean and Reducing Mud - Improving Drainage

french drain (Figure 2). A T-shaped pipe can be placed at the end of the french drain outlet to slow the speed of the water, and spread it out over a larger area (Figure 3).

Small Acr eage P rogram 2

GutterRafter

Downspout support

Downspout

Downspout adaptor

Underground outlet90 Degree elbow


Roof

Figure 2: Underground Gutter Outlet

Cross Section (front) Cross Section (side)

Perforated CPP for dissapating energy of rainwater Geotextile or weed cloth

Dispersion pit filled with 2 inch minus gravel fill lined with geotextile or weed cloth

Perforated CPP for dissapating energy of rainwater

Solid corrugated plastic pipe from gutters/french drain

“T” connectionEnd cap

6”

8”

3”Min. 3’

14”

6”20”

6”


Figure 3. T-shaped Buried Outlet

Plan View

Solid corrugated plastic pipe (CCP) from gutters/french drain

Perforated CPP for dissapating energy of rainwater

End cap

Min. 3’3”

20”

Geotextile or weed cloth

6”

French drains can also be used to collect water draining from adjacent properties and direct it on your property where it will not do any damage. French drains work best if they are not within the groundwater table. Heavy machinery and livestock should be kept off the french drain. They can

compact the soil, crush the drainage pipe and damage the drain, thereby blocking water flow and requiring repairs and possibly replacement.

Berms

Berms are low mounds of vegetated soil two to six inches in height. Berms direct and slow the speed of runoff, allowing it a greater chance to infiltrate and filter out sediments, nutrients and other materials in the water. Berms can also be used to divert water around a building, or at the base of a slope to direct runoff around an area such as a livestock turnout. Diverting this “run-on” water around livestock turnouts can greatly reduce mud in these areas.

Keeping Clean Water Clean and Reducing Mud - Improving Drainage 3

Grassy swales

Swales are shallow, gently sloped vegetated ditches that capture runoff and transport it away from heavy use areas. Swales are commonly planted with grass, which slows down runoff and facilitates infiltration and removal of sediment and other particles. Swales can be easily incorporated into the landscape on your property, particularly if there is already a low lying area on your property. Swales are often less expensive to install than some underground drainage systems. Swales should be designed to hold water for no more than 48 to 72 hours to reduce habitat for mosquitoes. If standing water is expected for longer periods of time, wetland plants such as rushes (Juncus spp.), cattails (Typha spp.) or sedges (Carex spp.) can be planted.

Maintenance should occur when the soil is not saturated to prevent compaction, which can limit infiltration of runoff. Cuttings should be removed to prevent smothering of the vegetation. Grazing of these areas may be possible, but should be controlled to maintain healthy vegetation. Do not graze during initial vegetation establishment, when the soil is wet or during reseeding of bare areas. Grass height should be maintained at no less than 3 to 4 inches tall. Shorter grass does not provide adequate erosion protection. Bare or eroded spots should be repaired and reseeded. The swale should not be used as a track or roadway. Frequent traffic may damage the swale and create ruts, which can concentrate water flow and eventually result in erosion and the formation of gulleys.

Dry wells

Directing downspouts into drywells can help facilitate infiltration of water into the surrounding soil and prevent it from picking up sediment from the surface. A dry well is a small pit lined with geotextile fabric or weed cloth and filled with 1½” to 3” gravel. Dry wells are best used to collect runoff from a small area with little or no sediment or pollutants, such as stormwater from a roof. Soils surrounding the dry well should be sufficiently permeable to allow adequate infiltration of the runoff. The dry well should be designed to completely drain the water volume into the soil within 48 hours of the rain event. An overflow may be needed to handle large amounts of runoff. Dry wells are relatively small and because they are underground, do not take up much space. They can be installed out of the way, provided the dry well can be easily accessed for maintenance.

Locate dry wells at least 10 feet from building foundations and at least 75 feet from wells, septic systems and surface water bodies.

Permits

Moving soil around on your property to build a french drain, drywell, berm or swale may require a grading permit if more than 50 cubic yards or more of material is moved. More information is available in the fact sheet Frequently Asked Questions: What Can You Do On Your Land? Before beginning any

work, contact Clark County Community Development at 360-397-2375 x 4347.

All of these drainage structures can help you manage runoff on your property, reduce mud and erosion, allow runoff water to infiltrate and recharge groundwater and maintain healthy water quality in Clark County surface waters.


http://clark.wsu.edu/horticulture/smallFarmProgram/sm-ac-FAQ9-3-04.pdf

The Small Acreage Program is sponsored in partnership by WSU Extension Clark County, the Clark County Clean

Water Program, and the Clark Conservation District.

Extension programs are available to all without discrimination. Report evidence of noncompliance to your local Extension office.

4


Keeping Clean Water Clean and Reducing Mud - Improving Drainage

For additional information on managing roof runoff and drainage, contact:

Washington State UniversityClark County Extension11104 NE 149th Street C 100Brush Prairie WA 98606360-397-6060 extension 7720http://clark.wsu.edu/

Clark Conservation District11104 NE 149th Street C 400Brush Prairie WA 98606360-883-1987 extension 110http://clark.scc.wa.gov/

USDA Natural Resource Conservation Service11104 NE 149th Street C 400Brush Prairie WA 98606360-883-1987 extension 3http://www.wa.nrcs.usda.gov/

Sources:

Alameda Countywide Clean Water Program (ACCWP). Grassy Swales Fact Sheet. From: ACCWP Catalog of Control Measures. n.d., 4 pp. http://www.oaklandpw.com/creeks/pdf/Grassy_Swales.pdf

Alberta Agriculture, Food and Rural Development. Grassed Waterway Construction. Agdex # 573-6. n.d., 3 pp. http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex795/$file/573-6.pdf?OpenElement

Connecticut Bureau of Water Management. Dry Wells. Connecticut Stormwater Quality Manual. 2004, 4 pp. http://dep.state.ct.us/wtr/stormwater/manual/CH11_DW_S-5.pdf

Houston Landscape Images. Grading and Drainage Work. n.d., 4 pp. http://www.houstonlandscape.com/Drainage.htm

McVay, K.A., G.M. Powell and R. Lamond. Maintaining Grass Waterways. Kansas State University, MF-1064. April 2004, 3 pp. http://www.oznet.ksu.edu/library/crpsl2/mf1064.pdf

Pfost, D.L. and L. Caldwell. Maintaining Grassed Waterways. University of Missouri Extension, G1504. October 1999, 3 pp. http://muextension.missouri.edu/explore/agguides/agengin/g01504.htm

Adapted by Erin Harwood, WSU Clark County Extension (September 2005).

http://clark.wsu.edu/

http://www.co.clark.wa.us/water-resources/index.html


http://www.clarkcd.org/

http://clark.wsu.edu/

http://www.clarkcd.org/


http://www.oaklandpw.com/creeks/pdf/Grassy_Swales.pdf

http://www.oaklandpw.com/creeks/pdf/Grassy_Swales.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex795/$file/573-6.pdf?OpenElement

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex795/$file/573-6.pdf?OpenElement

http://dep.state.ct.us/wtr/stormwater/manual/CH11_DW_S-5.pdf

http://www.houstonlandscape.com/Drainage.htm

http://www.houstonlandscape.com/Drainage.htm

http://www.oznet.ksu.edu/library/crpsl2/mf1064.pdf

http://muextension.missouri.edu/explore/agguides/agengin/g01504.htm

http://muextension.missouri.edu/explore/agguides/agengin/g01504.htm

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