introductory guide to steel building anatomysteel building anatomy | pg. 2 footprint the first thing...

STEEL BUILDING ANATOMYI N T R O D U C T O R Y G U I D E T O

STEEL BUILDING ANATOMY | PG. 2

FOOTPRINTThe first thing you will need to communicate is the layout (or

footprint) of your building. There are three important dimensions

you will need to convey to your building specialist:

• Width is the distance from the outside of the sidewall girt

on one sidewall to the outside of the sidewall girt on the

opposite sidewall.

• Length is the distance from the outside of the endwall girt

on one endwall to the outside of the endwall girt on the

other endwall.

• Eave Height is the distance from the bottom of the column

base plate to the top of the eave strut.


EXTERIOR WALL SURFACESMetal buildings have four exterior wall surfaces. Two of these walls

are called sidewalls and two of these walls are called endwalls.

• Sidewalls are characterized by a contact point between the

wall panels and the roof panels that aligns parallel with the

finished floor. The sidewall is where the gutters would attach.

It determines the length of the building.

• Endwalls are characterized by the roof slope which can be

observed where the wall panels meet the roof panels. On a

gabled building, this is the wall where the “A” line or peak of

the roof can be seen. On a single-slope building or a lean-to

building the endwall shows the wall sloping from a high to

low side. The endwall is the wall that determines the building

“width” dimension.


These four walls can further be identified as the:

• Front sidewall

• Left endwall

• Back sidewall

• Right endwall

This is how you would successfully communicate where you want

your walk doors, windows and large doors located.

Notice that these designations run clockwise around the

building perimeter.


PITCH OPTIONSThe point where the sidewalls meet the roof is called the eave.

Eave trim finishes the raw edges of the panels. One might choose

to add a gutter system to divert water from the roof and away

from the foundation. Eave height is determined by measuring the

distance from the bottom of the column base plate to the point

where the roof and sidewall intersect. (PLEASE NOTE: Eave height

and “clear height inside the building” are not the same. If you

require a specific clearance inside your building, please be sure

to let your sales representative know so that they can help you

to determine the necessary eave height that you will need). The

designations run counter-clockwise around the building perimeter.


The point where the two sloping halves of the roof meet is called

the peak. If you travel along the peak of the roof from endwall

to opposite endwall, this is known as the ridgeline. The roof

pitch or roof slope is usually shown as a ratio to 12 (i.e., ½:12, 1:12,

4:12, etc.).

When inches are used as a basic unit, a 2:12 roof pitch means that

the roof rises 2 inches in every 12 inches measured horizontally

across the width of the building from the sidewall to the peak of

the building.

If the building is 50’ wide and has a 14’ eave height, the height at

the peak of the roof would be 20’3” with 3.12 pitch.


FRAME TYPESA rigid frame is made of two upright I-beam columns and two

I-beam rafters. Our interior rigid frames can be designed as either

clear span or with interior columns. Typically building widths

greater than 80 feet are more economical with an interior column.

Endwall frames are typically a post and beam design for cost

effectiveness, but can be designed for future expansion whereby

a rigid frame expandable frame would be utilized. All frames are

finished with a red oxide primer.

Most rigid frame columns are tapered, but may be ordered

straight upon request. In most cases, a tapered column is

more economical.


Gabled (clear span)A double sloped building in which the ridge is in the center of

the building. Welded plate, tapered column “clear span” system,

available in 1:12 or steeper roof slope.

• Standard widths are 20′ to 120′

• Eave heights of 10′ to 25′

• Bay widths of 20′, 25′ or 30′

Greater widths and eave heights may be achieved upon request.


Gabled (with interior columns)A double sloped building in which the ridge is in the center of the

building. Available in:

• Widths of 80′ to 240′

• Eave heights of 12′ to 25′

• Standard bay lengths of 20′, 25′ or 30′

• Roof slope is 1:12 or steeper

Greater building widths may require more than one row of interior

columns to reduce building cost.


Single-slopeA roof that slopes in one direction with a high sidewall and

opposite low sidewall. Single-slope buildings are typically used for

strip malls, office complexes, or buildings along a road frontage.

Decorative façades or parapet walls are commonly used to hide

the roofline and provide an architectural appearance.

Single-slope buildings are also used when adding on to an

existing building that was not designed to carry the load of an

attaching building.


Lean-toA lean-to ties in at eave or below eave of another building.

Unlike the single-slope building, the lean-to does not have high

side columns, but instead the rafter attaches to the parent building

which is designed to take the forces of the lean-to.

Lean-to buildings provide a variety of uses from just a roof cover

area to a completely enclosed addition.

Width and height maximum dimensions will vary according to the

parent building dimensions.


SHEETING & TRIM DETAILSSearcy Building Systems builds come standard with sturdy 26

gauge PBR roof and wall panels. An industry favorite, the PBR

panel is extremely important on roofs because the bearing leg on

the panel protects against foot-traffic damage and helps prevent

the panel from “rolling” thus creating leaks. The PBR panel is one of

the most economical and durable covering systems available .

Our roof sheets are available in our standard PBR panel or one

of our optional standing seam panels. All of our roof panels are

available in 22, 24 or 26 gauge steel and come standard with a

Galvalume® finish. As an option, our roof sheets can be painted

with our 20 year baked on enamel paint system - this siliconized

polyester resin comes in 16 different colors from which to choose.

The Galvalume® substrate is a zinc and aluminum coating that is

applied over the bare steel panel to extend the life of the steel and

keep it from rusting.

Searcy Building Systems standard wall panels are available in a

PBR-panel or an optional architectural A-panel. Our wall panels

are available in 22, 24 or 26 gauge and are available in 16 different

siliconized polyester color choices. Trim is available in 26 ga.

matching or contrasting colors. SBS can also delete the wall panels

completely should you desire brick, block, stone or other exterior

finishes. Specialty panels like insulated sandwich panels or panels

that mimic a stucco finish are available upon request.


“PBR” roof & wall panelsThe Purlin Bearing Leg of this “R” profile panel rests on the purlin

to provide added strength and a better seal; thus reducing the

potential for leaks!


“R” roof & wall panelsPanel leg on overlap does not return all the way down the purlin.

This can compromise weather tightness!


BASE CONDITIONAt Searcy Buildings Systems, we are committed to saving you time

and money by detailing all of our building components to be as

efficient to install as possible. Our base condition detail (base angle

with flashing) is a strong example of this.

Our standard base condition is a 14 gauge base angle with 26

gauge counter-flashing. This eliminates the need for a concrete

sheeting notch, and allows your steel wall panels to rest upon a

matching steel trim piece instead of sitting inside of a corrosive

concrete notch condition.

Our base condition provides a barrier against rodents and vermin.

It is also quick and easy to install.

Others offer this only as an option, at an additional cost. SBS offers

this on every project - at no additional cost.


BRACING OPTIONSA steel building, though comprised of solid steel, is not as strong

as when all of its components are installed. Metal buildings face

constant stresses from wind, snow and large number of openings

that disrupt the continuous rigidity of the steel itself. Because of

these things, engineers must brace every metal building according

to the forces acting on that particular building. All steel buildings

are designed with flange bracing (the bracing found in the roof)

to keep the purlins from rolling under high stress conditions.

Likewise, the panels themselves provide a large degree of bracing.

This can be seen especially well when the wall sheets are being

installed. It is fascinating to watch as the wall girts firm up when

the sheets are being applied. For the most part; however, we

also utilize additional bracing types to further support your steel

building. As a rule, one bay per each wall must be braced. In order

of expense we use the following additional methods of bracing.


X-bracing/Rod-bracingX-bracing employs steel rods or cables to connect various

parts of the frame tightly. X bracing is typically used when there

are not many accessories added to the building package and it

is acceptable that we stretch rod or cable across one bay on

each wall.


Wind columnThere are instances when it is not acceptable to obstruct a bay at

any of the sidewalls. A wind column (or soldier column) is a vertical

member which stands beside and reinforces a rigid frame column.

These can only be used when seismic forces, wind loads or building

dimensions permit.


Portal frameWhen a wind column cannot be used, engineers will design the

wall using a portal frame. It is made of two portal columns and a

portal rafter placed between the two adjacent mainframe columns

in a bay.

It is important to be sure the opening within the braced bay is clear

of the portal rafter.


SUMMARY OF BUILDING ANATOMY & TERMINOLOGY

Phone: 844-573-2729 | Email: [email protected]

S E A R C Y B L D G S . C O M

introductory guide to steel building anatomysteel building anatomy | pg. 2 footprint the first thing...

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