foundationswaterproof the walls in elevation, i.e. a damp proof course, or dpc. when building in...

1FOUNDATIONSTechnical Specifications

Waterproofing works in contact with the ground should be planned and carried out with great care, bearing in mind that the life of the coating must be the same as that of the protection work, and that it is most unlikely that any remedial work will be possible, so a lack of waterproofing or defective waterproofing could be very costly indeed.So the selection of materials should focus on products that maintain their characteristics - impermeable to water and water vapour, rot resistance and me-chanical resistance over time, even when subject to site traffic. Nor should it be forgotten that the problem if damp in structures that are underground or in contact with the ground is often related to thermal insulation, and that very frequently damp is attributed to the non-impermeability of the structure, rather than to condensation of damp air due to the inadequate thermal resistance of floors and walls in contact with the ground.So the designer must ensure that the following aspects are checked:• the water that rises from the ground through capillary action, from an unconfined aquifer or by rainwater washout.and also:• the water contained as vapour in the telluric area that migrates with changes in barometric pressure and temperature, and that can condense on cold sur-

faces.• the water produced and contained in the form of vapour in air of basement spaces that can condense on cold surfaces.To resolve these problems, INDEX SpA has developed a polymer-bitumen membranes reinforced with “non-woven” single-strand polyesters, FlEXTEr TES-TuDo and HElASTA PolYESTEr. The sheets are rotproof and resistant to traction and perforation. They have good resistance to vapour diffusion, and may therefore be successfully used in waterproofing systems in underground closures both against rising damp due to capillary action and in the presence of an unconfined aquifer.ArMoDIllo is the most recent waterproofing membrane designed to protect underground walls. It is an armoured and draining membrane that provides waterproofing, drainage and protection in a single product.FluXAN and SATurFIX additives for concrete and mortar , together with EXPAN BENToNITICo water expanding cord, produced by INDEX SpA., permit homogeneous and impermeable foundations and screeds to be laid which, in synergy with the membranes, ensure that the desired objective is achieved.This publication also suggests insulating systems and accessory works appropriate to the varying uses of the spaces with walls or floors in contact with the ground.

Waterproofing works in contact with the ground

1a LINEA1a DIVISIONE

FOUNDATIONS

5Technical Specifications

2 FOUNDATIONS Technical Specifications

Masonry in direct contact with the ground is subject to the entrance and diffusion of damp inside them, due to the physical phenomenon of capillary action.The strength of the capillary action is enhanced by porous construction materials (clay blocks), the presence of salts dissolved in the water, and low temperatures.Dampness in the ground may be due to:– dispersedrainwater– waterfromanunconfinedaquiferIn particular situations, with sufficiently drained ground over deep unconfined aquifers, and for spaces that are not underground, it may be enough to install only an impermeable layer to waterproof the walls in elevation, i.e. a damp proof course, or DPC.

When building in areas with a shallow uncon-fined aquifer or in the presence of possible accumulations of infiltration water, it should be recalled that the ground of different sites differs in its capacity to draw water, depending on its nature. Water can rise by capillary action from 0.3m up to a maximum of 1.5m through sandy soil over an aquifer, while in clay soil water it can rise from 3m to 8m.

It is evident that in these cases all the sur-faces in contact with the ground must be damp-proofed, not just the accessory works mentioned above.These damp proofing solutions will block the passage of the damp dispersed in the ground, but often the damp that affects works in con-tact with the ground is not solely due to capil-lary action phenomena, but is related to the hygrothermal problems of the spaces created by these works.The water present in the form of vapour in the air of the premises may condense on the so-called “cold wall”, in this case the sur-faces in contact with the ground, and cause an anti-hygienic situation even if proper damp proofing has been done; condensation is char-acteristic of underground spaces in the spring and summer in premises that are not heated during the winter, due to the thermal inertia of the ground and the structure. So the structure needs adequate thermal pro-tection in addition to water-proofing. The problem of damp is particularly accentu-ated in poured concrete structures, and so in this case it is always best to check that the concrete is perfectly dry before using the underground spaces.

Another phenomenon, albeit a rarer one, which occurs in particular situations (large underground spaces on filtering ground and a deep aquifer) is the damp contained in the telluric area between the level of the aquifer and the structure, which may, after a sharp fall in atmospheric pressure, in winter or on summer nights when the ground I at a higher temperature than in the unheated space, may be drawn to the surface and condense on the coldest surfaces. In this case the damp-proofing will act as a “vapour barrier” since these materials have good resistance to the spread of vapour.

INTRODUCTION

Damp Proof Course

Cold wall

condensate.

ambient air

Waterproofing

HEIGHT OF RISE BY CAPILLARY ACTION

SANDY SOIL CLAY SOIL

insulation + vapour barrier

ambient air


This will be composed of a 4 mm thick bitu-men polymer elastoplastomer waterproof mem-brane, based on distilled bitumen, plastom-ers and elastomers, reinforced with Spunbond “non-woven” single-strand polyesters stabi-lised with glass fibre, FLEXTER TESTUDOSPUNBOND POLIESTERE 4, certified by Agreement with ITC-CNR (ex ICITE). The mem-brane will have L/T tensile strength (EN12311-1) of 850/700 N/50 mm, elongation at rupture (EN 12311-1) of 50/50%, nail tear strength (EN12310-1) of 150/150 N, dimensional sta-bility when hot (EN1107-1) ±0.3/±0.2%, cold

bend (EN1109) of -20°C and flow resistance (EN1110) of 140°C.The sheets are laid dry on wet-mix concrete and with 10 cm overlaps. The overlap will be bonded with a propane gas burner flame and the sheets will be turned back and flame-bonded to the edge of the foundation, to prevent water rising through capillary action in vertical walls. The membrane may be covered with a layer of expanded clay granules (granulometry 8-15) or a compression-resistant insulation panel, of sufficient thickness to prevent condensation on

the floor. The underfloor will be laid over this. If the hygrothermy of the environments requires it (premises in which large amounts of steam are produced), for steam-proof insulation a vapour barrier must be applied over the sub-floor.

The vertical drainage layer will be created with PROTEFON, a studded drainage sheet in HDPE, resistant to chemical agents, bacteria and soil moulds. The sheet will have 8 mm thick studs, compression resistance of 19,000 kg/m2 and drainage capacity of 3 m3/h m. The sheet is applied with the studded face

against the cement surface, with overlaps of approximately 10 cm, joined by interlocking the studs of the studded sheet. The sheets will recover the foundation block to connect with the perimeter drainage pipe and continue 10 – 15 cm over the ground, attached mechanically using the special profile.

Floorincontactwiththeground,onclaysoilsinwhichrainwaterpocketsaccumulate,onslopinggroundThe dispersed water will be collected in drain-age channel laid under a pavement The use of a prefabricated drainage layer to cover the vertical portion may be advantageous when there is not enough draining filler. The damp that rises by capillary action will be blocked by a continuous damp-proof layer applied to weak-mix concrete.

FLOOR IN CONTACT WITH GROUND ON DAMP SOILSA

SITUATION

VERTICAL DRAINAGE LAYER

Floor

InsulationClay

1. FLEXTER TESTUDO membrane

2. PROTEFON

3. Draining pipe

WATERPROOF MEMBRANE1

2


Buried works in draining soils protectedwith reinforced anddrainingmembrane.The proposed technical solution concerns the underground part of buildings constructed on soil that drains sufficiently, in the absence of an unconfined aquifer, and so the impermeable coating only involves the masonry against the ground, not the flooring of the basement spaces, since it is believed that rainwater will be dispersed by gravity from the drainage belt. To protect the walls against the dampness of the soil, bituminous paints or molten bitu-men are often applied. To be truly efficacious, the layer applied should be around 3-4 mm thick, but very often it is hard to apply a uniform layer, and in addition the protective film is not reinforced, and fissures when the first hairline crack appears in the cement surface, so it is much more effective to use a prefabricated membrane reinforced with a polyester non-woven fabric that can offer superior elasticity, uniform thickness, and resistance to punching and crazing. The coating should then be protected to ensure it is not pierced during the backfill phase, and adequate vertical drainage should be provided, connecting to the perimeter drainage system laid at the foot of the building to avoid standing rain water next to the waterproofing. The use of a specialised prefabricated layer to provide waterproofing, drainage and protection may be advantageous when there is not enough draining filler.

CELLARS, BASEMENTS AND WALLS AGAINST THE GROUND ON DRAINING SOILSB

SITUATION

After the primer has dried, ARMODILLOPOLIESTERE, a special multifunctional water-proofing membrane, a protective and draining reinforced elastoplastomer bitumen polymer, reinforced with high resistance non-woven polyester fabric will be applied by torch to full adherence. ARMODILLO is the multifunctional waterproof-

ing membrane that performs all the functions listed above on its own.Using additives in the concrete mix, as indicat-ed in the subsequent cases only the perimeter foundation slab, which constitutes the deepest

part of the work and the part most exposed to water, is a useful precaution in areas with heavy rainfall.The upper surface of the membrane will be reinforced with 6 mm thick rhomboid plaques of bitumen polymer mix at a density of 1,567 plaques/m2. The thickness of the membrane, in flat parts, must be 2.5 mm, and it must resist dynamic punching by a 1 kg hammer falling from a height of 50 cm onto a two blade punch compliant with UNI8202.The membrane must adhere to the concrete with a force of over 100 Kpa. The reinforced

membrane should be bonded in total adher-ence by torch to the wall to be coated, with the studded side outermost. The sheets are overlapped and sealed laterally along the over-lap line marked in the membrane, while the top edges of the sheets will be sealed by bonding the top of the membrane to a 14 cm wide strip of polyester reinforced membrane DPC previ-ously bonded to the wall. The more difficult connections and details will be made using TESTUDO smooth surface membrane rein-forced with non-woven polyester fabric.The waterproof membrane will extend above ground for at least 20 – 30 cm. To avoid blocking the drainage space by finer soil elements, a filter layer of FILTRO non-woven polyester fabric of 200 g/m2 will be attached to the gently torched thermoadhesive studs of the membrane. The filter will then be lapped on the drainage pipe at the foot of the underground wall.

EXAMPLES OF FOUNDATIONS WATERPROOFED WITH “ARMODILLO” REINFORCED MEMBRANE

1. ARMODILLO POLYESTER

Floor2. Polyester TNT filter

3. Drainage pipe

PRIMER1


The surface of the wall against the ground will first be treated with a coat of INDEVER bitumi-

nous primer: this is a bituminous solution based on bitumen oxidate, additives and solvents, with

a dry residue of 40% and viscosity (UNI EN-ISO 2431) of 12 - 17 s

Plaques on thereinforced surface of ARMODILLO


Buriedworksindrainingsoilsprotectedwithself-adhesivemembrane.The proposed technical solution concerns the underground part of buildings constructed on soil that drains sufficiently, in the absence of an unconfined aquifer, and so the impermeable coating only involves the masonry against the ground, not the flooring of the basement spaces, since it is believed that rainwater will be dispersed by gravity from the drainage belt.To avoid using a torch or hot spreading techniques, bituminous paints or emul-sions that can be applied cold are used, applied at 2- 3 kg/m2.The thickness of the layer was no more than 2 mm after drying, and often it was not hard to apply a uniform thickness. In addition, the unreinforced bituminous film crazed when the first hairline crack appears in the cement surface So it is much easier to use a self-adhesive prefabricated membrane reinforced with polyester non-woven fabric that can offer superior elasticity, uniform thickness, resistance to punching and crazing, and can be applied cold. The coating should then be protected to ensure it is not pierced during the backfill phase, and adequate vertical drainage should be provided, connecting to the pe-rimeter drainage system laid at the foot of the building to avoid standing rain water next to the waterproofing. The use of a specialised prefabricated layer to provide drainage and protection may be advantageous when there is not enough draining filler.

CELLARS, BASEMENTS AND WALLS AGAINST THE GROUND ON DRAINING SOILSC

SITUATION

3. Drainage pipe

Floor

2. PROTEFON•TEX

1. SELFTENE BASE POLYESTER membrane

From the top of the wall to a level of at least 20÷30 cm above ground, a waterproof mem-brane in elastomer bitumen polymer with com-posite reinforcement in non-woven polyester fabric stabilised with glass fibre, and its lower surface spread with a 2 mm thick layer (EN 1849-1) of SELFTENE BASE POLIESTERE, a self-adhesive mix is bonded in total adherence by pressure at ambient temperature. The membrane has L/T tensile strength (EN12311-1) of 400/300 N/50 mm, elongation at rupture (EN 12311-1) of 40/40%, nail tear strength (EN12310-1) of

130/130 N, cold bend (EN1109) of -25°C, and adhesion (Tack Adhesion Test) of 400 N/cm2 at 20°C and 350 N/cm2 at 5°C.The membrane sheets are cut to size and arranged vertically on the wall to be coated, removing the silicone film covering the underside and pressing them by hand to adhere to the treatment surface.The sheets are overlapped 8 cm longitudinally along the special overlap area; after removing the double-sided silicon protective band they are carefully pressed together, using a roller. For

transverse overlaps, or to overlap parts of sheets without silicon banding, they will be overlapped at least 12 cm and bonded in the same way. The adhesion of the top of the sheets, above ground, will be finished by torch or hot air and the tops of the sheets fixed mechanically with 3 nails per linear metre, with washers of at least 20 mm.


The vertical protection and drainage layer will be created with a studded sheet in HDPE com-bined with a polypropylene non-woven filter-ing fabric resistant to chemical agents, bacteria and the mould present in the ground, such as PROTEFON•TEX, with surface mass of 775 g/m2.The sheet must cover all the waterproof cover-ing, and the stud studs will be 8 mm thick. The

sheet will have compression resistance of 19,000 kg/m2 and draining capacity 16.6 m3/h·m. The sheet is applied with the face covered with the non-woven fabric against the earth fill, with over-laps of approximately 10 cm, joined by interlock-ing the studs of the studded sheet.The tops of the sheets will cover the part of the waterproof membrane protruding above ground,

and will be attached mechanically and protected using the special plastic profile.At the foot of the wall against the ground, the non-woven fabric will be separated from a 40-50 cm high strip of studded sheet and turned onto the perimeter drainage pipe to avoid blockage caused by the finer parts of the fill soil.

DRAINING AND FILTERING PROTECTIVE LAYER3

PRIMER1

The surface to be treated must be clean and dry, with no release agents present that might interfere with the adhesion of the primer and the membrane. All the metal spacers must be cut and nipped from the shuttering, and any

blobs of cement protruding from the wall that might pierce the waterproof membrane must be removed. A coat of INDEVERPRIMERE is applied to the whole of the surface to be treated, at 300-500 g/

m2 depending on the porosity of the surface. The primer has a dry residue (UNI 8911) of50% and a viscosity in a DIN viscosity cup (UNI EN ISO 2431) of 20 – 25 s.

The concrete for waterproof foundations must be made of low hydration heat cement with a ce-ment content of 350 kg/m3 or more, and at least 5% of the total weight consisting of fine grain (0.2 mm granule) aggregate with perfect granu-lometry (UNI 7163). The water/cement ratio must be no more than 0.45. Waterproof concrete will be obtained by adding 1.5% by weight of cement of FLUXAN superfluidising additive and 1% by weight of cement of SATURFIX waterproofing additive. Appropriate amounts of the additives

will be added during mixing, and the concrete mixture must be mixed for a further three min-utes. Excessive vibration times during pouring must be avoided, and the concrete must be ma-tured properly. FLUXAN additive must have the following characteristics and properties: product density 1.15±0.01 kg/l, dry residue to UNI 7111-72 standard 32%; surface tension of the prod-uct in aqueous solution in a 0.5 ratio of water to cement according to the UNI 7117-72 standard: 0.078 N/m; chlorine free content according to

UNI 7117-72; quantity of water required to obtain a normal mix (according to DM 3/8/86 Chapter II, section I, article 7): 120 cc; reduction of wa-ter in mix with FLUXAN additive content 1.5% of cement mass: 15%. SATURFIX additive must have the following characteristics and properties: product density at 20°C, 1.03±0.01 kg/litre; pH 9.

PREPARATION OF CONCRETE FOR POURING FOUNDATIONS AND WATERPROOF SLABS4


UndergroundspacesinclaysoilsThis is a situation with a high risk of damp penetration. Clay soils are able to draw water from an aquifer from 3 to 8 m deep, and during rain they retain rainwater for long periods of time.The proposed solution involves coating the walls against the ground and the horizontal masonry under the floors with a 4 mm thick membrane rein-forced with non-woven polyester fabric, plus fluidising and waterproofging additives in the poured foundations. Particular attention must be paid in the design stage to the level that a sudden rise in the unconfined aquifer might reach, since, if the layers laid on top of the waterproof membrane on the horizontal part is not able to counterbalance the thrust this could cause shear failure in the floor and the membrane. If the level of the aquifer is vari-able, the next solution should be adopted.

CELLARS, BASEMENTS AND WALLS AGAINST THE GROUND ON DRAINING SOILSD

SITUATION

3. Drainage pipe

FloorMembrane

2. PROTEFON TEX

1. FLEXTER TESTUDO membrane

After the primer has dried, a 4 mm thick bitu-men polymer elastoplastomer waterproof mem-brane, based on distilled bitumen, plastom-ers and elastomers, reinforced with Spunbond “non-woven” single-strand polyesters stabi-lised with glass fibre, FLEXTER TESTUDOSPUNBOND POLIESTERE 4, certified by Agreement with ITC-CNR (ex ICITE) will be bonded in full adhesion by torching. The mem-brane will have L/T tensile strength (EN12311-1) of 850/700 N/50 mm, elongation at rupture

(EN 12311-1) of 50/50%, nail tear strength (EN12310-1) of 150/150 N, dimensional stability when hot (EN1107-1) ±0.3/±0.2%, cold bend (EN1109) of -20°C and flow resistance (EN1110) of 140°C. The considerations made in the pre-ceding chapters apply to the issue of thermal insulation.The sheets are spread dry on a weak mix, and overlapped approximately 10 cm. The overlap-ping sheets will be carefully torched and the overlap turned and torch bonded to the vertical

parts for at least 10 cm above floor level.


The vertical protection and drainage layer will be created with a studded sheet in HDPE combined with a polypropylene non-woven filtering fabric re-sistant to chemical agents, bacteria and the mould present in the ground, such as PROTEFON•TEX, with surface mass of 775 g/m2.The sheet must cover all the waterproof cov-ering, and the stud studs will be 8 mm thick. The sheet will have compression resistance of

19,000 kg/m2 and draining capacity 16.6 m3/h·m. The sheet is applied with the face covered with the non-woven fabric against the earth fill, with overlaps of approximately 10 cm, joined by interlocking the studs of the studded sheet.The tops of the sheets will cover the part of the waterproof membrane protruding above ground, and will be attached mechanically and protected using the special plastic profile.

At the foot of the wall against the ground, the non-woven fabric will be separated from a 40-50 cm high strip of studded sheet and turned onto the perimeter drainage pipe to avoid blockage caused by the finer parts of the fill soil.

DRAINING AND FILTERING PROTECTIVE LAYER3

The concrete for waterproof foundations must be made of low hydration heat cement with a cement content of 350 kg/m3 or more, and at least 5% of the total weight consisting of fine grain (0.2 mm granule) aggregate with perfect granulometry (UNI 7163). The water/cement ra-tio must be no more than 0.45. Waterproof con-crete will be obtained by adding 1.5% by weight of cement of FLUXAN superfluidising additive and 1% by weight of cement of SATURFIX wa-terproofing additive. Appropriate amounts of the additives will be added during mixing, and

the concrete mixture must be mixed for a fur-ther three minutes. Excessive vibration times during pouring must be avoided, and the con-crete must be matured properly. FLUXAN addi-tive must have the following characteristics and properties: product density 1.15±0.01 kg/l, dry residue to UNI 7111-72 standard 32%; surface tension of the product in aqueous solution in a 0.5 ratio of water to cement according to the UNI 7117-72 standard: 0.078 N/m; chlorine free content according to UNI 7117-72; quantity of water required to obtain a normal mix (accord-

ing to DM 3/8/86 Chapter II, section I, article 7): 120 cc; reduction of water in mix with FLUXAN additive content 1.5% of cement mass: 15%. SATURFIX additive must have the following characteristics and properties: product density at 20°C, 1.03±0.01 kg/litre; pH 9.

PREPARATION OF CONCRETE FOR POURING FOUNDATIONS AND WATERPROOF SLABS4

PRIMER1The surface of the wall against the ground will first be treated with a coat of INDEVER bitumi-

nous primer: this is a bituminous solution based on bitumen oxidate, additives and solvents, with

a dry residue of 40% and viscosity (UNI EN-ISO 2431) of 12 - 17 s


UNDERGROUND SPACES CONSTANTLY UNDER UNCONFINED AQUIFER OR NEAR THE AQUIFERE

UndergroundspacesconstantlyorperiodicallyunderunconfinedaquifersCoordination of the various phases and opera-tors on a site is essential for successful works and also because a defect in the primary water-proofing system can make the underground spaces unusable. In the presence of an aquifer, waterproofing should be supplemented by add-ing additives to pouring concrete and inserting cords in expanded polyethylene in the interface of the construction joints. This waterproofing system is much more challenging than the previ-ous ones, and particular care must be taken in selecting the materials, laying the foundation and designing the accessory works. The next few sections contain some suggestions. The material proposed, HELASTA POLIESTERE 4, is a bitumen-elastomer membrane reinforced with a polyester non-woven fabric; given the

very high elasticity of the compound coating the non-woven, it can absorb hairline cracking of the surfaces to which it is applied, and any shifts that occur between the weak mix and the foundation without breaking, remaining waterproof even under strain. The entire load-bearing and water pressure resistant foundation is contained by the waterproof membrane. To execute the works, the level of the unconfined aquifer surrounding the area to be excavated for the foundations must first be lowered: well point pumping systems are used, working continuously, and fitted with backup circuits that cut in if there is a breakdown in the main system or a power cut.It is very important to ensure that pumping is continuous, because if the pumps stop the aquifer will rise and move or damage the works that have not yet reached the necessary weight and resistance to counterbalance the thrust of

the water. To level the base of the excavation, a trowelled smooth concrete bed is created that will constitute the base on which the waterproof membrane, and then the main foundation will be laid. So the coating, consisting of two HELASTAPOLIESTERE membranes is applied on top of this bed. Subsequently, after the foundation has been poured and the perimeter walls erected, this will be joined to the horizontal waterproofing and the same coating will continue vertically up to 30-50 cm above ground.

SITUATION

E1

to the pumping station

Probe

Aquifer

3. Protefon

2. HELASTA POLYESTER membrane


1. Concrete

E2

to the pumping station

Probe

Aquifer

4.PROTEFON



2. EXPAN BENTONITICO

1. Concrete with additives

1

2

3

1

2

3

reinforcement

HELASTA

shuttering

weak mix

sheet

hood

hood

polyester weak mix

shutteringremovable protective skim

Detail of pumping phase to lower the aquifer Installing waterproof membrane directly on the weak mix bed and subsequent protection with hood

Poured concrete and smoothing of the base to receive waterproofing Detail of waterproofing of wall in elevation


In the excavation area, the level of the uncon-fined aquifer will be lowered and maintained at a level at least 50 cm below the base of the excavation.The base of the pit will be levelled with a carefully trowelled bed in weak concrete, and the foundation shuttering will be laid on this. The internal part of the base of the shuttering will include a triangular-section wooden angle piece of 5 cm per side, to round off the join between the horizontal and vertical planes. Two coating layers will be applied to the weak concrete, each composed of a 4 mm thick bitumen polymer elastoplastomer waterproof membrane, based on radial styrene-butadiene thermoplastic rubber and distilled bitumen, with elongation at rupture of 2000% and elastic recovery of 300%, reinforced with HELASTAPOLIESTERE 4 Spunbond “non-woven” sin-gle-strand polyesters, certified by Agreement with ITC-CNR (ex ICITE).The membrane will have L/T tensile strength (EN12311-1) of 900/700 N/50 mm, elongation at rupture (EN 12311-1) of 50/50%, nail tear strength (EN12310-1) of 200/200 N, fatigue resistance at -20°C (UEAtc) of over 1000 cycles on new material and over 500 cycles on arti-ficially aged material, cold bend (EN1109) of -25°C and heat stability (EN1110) of 100°C.The first layer is laid dry on the weak mix concrete, with 10 cm overlaps bonded with a propane gas torch and turned onto the founda-tion shuttering; the second layer, laid covering the joins in the previous sheet, will be fully torch bonded to the first layer to cover the foundation shuttering, again with 10 cm overlaps. To avoid tears in the waterproof membrane while the foundation reinforcement iron is being

laid, it will be covered with a 3-4 cm thick skim of concrete, and sheets of wood will be placed to protect the vertical part covering the shut-tering. After the reinforcement has been laid and the foundation slab poured, the protective wood panels will be removed before the slab has set, and the protruding edges between the base of the foundation and the wall in elevation will be rounded with a trowel.The foundation shuttering will be left in place until the walls have been erected. The walls will be treated with a coat of INDEVER bituminous primer: this is a bituminous solution based on bitumen oxidate, additives and solvents, with a dry residue of 40% and viscosity (UNI EN-ISO 2431) of 12 - 17 sThe shuttering will then be removed and the band of protruding membrane will be turned in and bonded to the base of the foundation.The vertical coating will consist of two mem-branes of the same joined by torch to the hori-zontal coating with an overlap of at least 20 cm.The first layer will be bonded by torch to the wall up to a height of 30-50 cm above ground, including a 10 cm overlap, and the second layer will be laid to cover the joins in the first one, and fully bonded by torching in the same way.The only difference between solution “E” and method ”D” is the different system used to connect the horizontal and vertical water-proofing. The membrane spread over the weak mix foundation bed is left flat and the part that will not be covered by the resist-ant foundation will be protected by a loose-laid 500 g/m2 non-woven polyester fabric. A 2-3 cm thick layer of cement mortar will be spread over this to provide further mechani-cal protection. The cement mortar applied

to the non-woven fabric does not adhere to the waterproofing and this protection may therefore be removed easily before jointing the horizontal and vertical coatings.

WATERPROOF MEMBRANE

The concrete for waterproof foundations must be made of low hydration heat cement with a cement content of 350 kg/m3 or more, and at least 5% of the total weight consisting of fine grain (0.2 mm granule) aggregate with perfect granulometry (UNI 7163). The water/cement ratio must be no more than 0.45. Waterproof concrete will be obtained by adding 1.5% by weight of cement of FLUXANsuperfluidising additive and 1% by weight of cement of SATURFIX waterproofing additive. Appropriate amounts of the additives will be added during mixing, and the concrete mixture must be missed for a further three minutes.

Excessive vibration times during pouring must be avoided, and the concrete must be matured properly.FLUXAN additive must have the following characteristics and properties: product den-sity 1.15±0.01 kg/l, dry residue to UNI 7111-72 standard 32%; surface tension of the product in aqueous solution in a 0.5 ratio of water to cement according to the UNI 7117-72 stand-ard: 0.078 N/m; chlorine free content according to UNI 7117-72; quantity of water required to obtain a normal mix (according to DM 3/8/86 Chapter II, section I, article 7): 120 cc; reduction of water in mix with FLUXAN additive content

1.5% of cement mass: 15%.SATURFIX additive must have the following characteristics and properties: product density at 20°C, 1.03±0.01 kg/litre; pH 9.

PREPARATION OF CONCRETE FOR POURING FOUNDATIONS AND WATERPROOF SLABS

In the interface of the construction joints of the foundation works, water tightness will be obtained with a waterstop consisting of an EXPAN BENTONITICO water-activated expanding rubber cord with 100% expan-

sion after 7 days’ immersion. The cord will be attached at 20-30 cm intervals with steel nails, although a POLIBOND PUR polyurethane adhesive should be used if the surface is irregular. The EXPANBENTONITICO should be

applied immediately before pouring, attached 7-8m from the edge, joined by laterally over-lapping the two ends of the cord to be joined 10 – 15 cm.

WATERSTOP

The membrane protection layer applied to the walls against the ground will be created with PROTEFON, a studded drainage sheet in HDPE, resistant to chemical agents, bac-teria and soil moulds. The sheet will have 8

mm thick stud and compression resistance of 19,000 kg/m2. The sheet is applied with the face covered with the non-woven fabric against the soil, with overlaps of approximately 10 cm, joined by interlocking the studs of the studded

sheet. The sheets will be attached mechanical-ly, using the special profile, at 10-15 cm above the ground, and will entirely cover the water-proof membrane to the foot of the foundation.

PROTECTION LAYER

1

2

3

4


Waterproofing with bituminous membrane has been carried out for heads of water of up to 25 m. It is generally considered that water-proofing with bituminous membrane can resist vertical pressure of 0.8 N/mm2, which can be increased to 1.2 N/mm2 if deformation is prevented.The foundation waterproof membrane may be subject to notable strain by the concrete structures covering it, and cracks can appear on the walls. An 8 mm double layer system as proposed in the preceding pages is considered able to sustain cracks up to 20 mm wide.

The materials

The system of covering the vertical wall of the foundation by bond-ing the waterproof membrane to it is the safest, since the membrane adheres fully to the works it is protecting. But this requires a lot of space. Often the breadth of the excavation does not permit work on the outside of the vertical foundation wall, and hence it is not possible to cover it using the procedure indicated in the preceding chapters. In this case a liner must be installed along the perimeter of the founda-tion, to which the waterproofing will be bonded.

On some soils it may also be necessary to reinforce the weak mix concrete and any liner installed.

On the piling, the weak mix concrete must be thicker on the head of the piles to distribute the load better, and the weak mix must be suitably shaped in the presence of irregular foundation slabs. When foundations are built on non-load bearing soils, it is common practice to consolidate them with a piling; but if adequate precautions are not taken the weak mix concrete can break in the area between the soil and the piles, threatening the integrity of the coating. To avoid this problem the remaining concrete must also be reinforced, connecting it to the piling.

In certain situations, when the thrust of the aquifer is expected to raise the resistant foundation, it may be necessary to connect the foundation reinforcement to a reinforcement sunk into the piles, and so the iron must pass through the waterproofing. These points can constitute weak points in the membrane, and so the problem must be resolved with special metal elements with a broad bed to connect to the coating and possibly also a flange and counterflange system. The membrane that will subsequently be gripped by the flange will be torched to the joining bed, which has been previously coated in primer. If poorly executed, this solution can cause major problems and so should only be used in situations that cannot be resolved in any other way.

The foundation

Liner

Reinforced weak mix concrete

Foundation

Foundation

Thickening

FoundationPile

Reinforced weak mix concrete

Weak mix concrete breakage point

Reinforcement

Foundation

Reinforcement

joining plate

Existing foundation

weak mix

All the surfaces destined to receive the waterproof membrane must be trowelled smooth, all the angles and joints between layers must be rounded with a radius of curvature of at least 5 cm.

Preparation of the surface to be covered

DETAILS OF INSTALLATION


To avoid penetration of damp due to rain water bouncing off pave-ments, two damp proof courses should be installed, linking them with a vertical coating.

Damp Proof Course

Joints between constructed parts that might settle in different ways must be avoided as far as possible. If unavoidable, the possible solu-tions are:

In the case of large joins, the vertical waterproofing will rest on a liner.Joints

Protective plate

HELASTA POLYESTER

rubber strip/band

elastic joint

high pump

compressible cord

The number of points at which the walls against the ground are breached must be reduced to the indispensable minimum. The device to connect to the waterproof membrane may consist of a metal sleeve with a large flange and welded bolts to be sunk into the concrete.The flange will be coated with primer and a piece of membrane 15 cm wider bonded to it. This will serve as joint with the waterproof covering.The sleeve will be fitted with a metal ring for a gasket.The internal part of the sleeve will also be fitted with a flange and bolts to tighten the gasket against the pipe.

Throughpipes

Membrane

Counterflange Flange Pipe

Gasket

stop ring for gasket welded to pipe

This device may also be used when the continuity of the membrane under the pillars of a framework must be guaranteed without having to attach the membrane with a flange. To resist damp due to capillary action only, it is sufficient for the membrane to be well bonded to the joining bed.

Connection devices

Iron bars

Iron bars

Plate

Membrane

joining plate

joining plate

weld


Waterproofing masonry against the ground with cement-based materials, rectification of damp walls and waterproofing of underground rooms from the inside are dealt with in the division 4 publications.• Technical Specifications 01 – rectifying damp walls with dehumidifying plasters• Technical Specifications 02 – Waterproofing with osmotic cements

If the soil permits, it is always preferable to construct a shaft that is not attached to the wall without a reinforced concrete base, with the bottom full of gravel connected to the vertical and perimeter drainage.

This will ensure that the body of the shaft does not detach from the wall due to settling of the building, breaking the continuity of the waterproof membrane. If the shaft needs to be attached to the con-struction, the side walls as well as the bottom need to be connected: the side walls must be tied into the walls of the construction. The membrane will cover it completely, and the adequately waterproofed bottom will be built with a slope towards the rain guttering connected to the perimeter drainage system.

Basement windows

grating

Membranedrainage

drainage

A well-designed drainage system may in many cases constitute a true security system, avoiding the passage of water inside the construction also in the presence of waterproof covering. It is important to include effective drainage to reduce hydrostatic pressure close to the mem-brane, so that even in the presence of faults in the covering the amount of water passing through will be reduced considerably.The drainage network generally consists of:• horizontal drainage (subfloor)• perimeter drainage system (at the foot of the foundation)• vertical drainage (close to the walls against the ground).The horizontal drainage will be joined to the perimeter drainage through perforated pipes, and will be maintained at a higher level. The perimeter drainage system with perforated pipes, will be connected at a constant slope of 1% to a discharge manifold.The vertical drainage, connected to the perimeter system, will also act as a layer protecting the waterproofing during backfilling. It will consist of porous cement blocks loose laid against the vertical wall and draining polystyrene panels or sheets of PROTEFON•TEX.It may also consist of gravel; in this case the waterproof membrane needs first to be protected with a non-woven polyester fabric of 300±500 gr/m2 or with PROTEFON.In clay soils, to avoid blocking the drainage system, all three of the elements of which it is composed should be protected with a filtering layer of Filter non-woven polyester of 200 gr/m2 with a 10 cm overlap of the sheets.

Drainage and protection of the waterproof membrane

perimeter drainage system

vertical drainage

horizontal drainage

Steps must be built after the wall against the ground has been water-proofed, and will be separated from the wall by a gap of at least 2 cm. The bottom will be fitted with a drainage grating linked to the perimeter drainage system.

External cellar steps


Technical Specifications

03/2011in

g

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