C S S B I
C S S B I
652 Bishop Street North, Unit 2A
Cambridge, Ontario N3H 4V6
Telephone: (519) 650-1285
Fax: (519) 650-8081
G E T T I N G I N TO
Light Gauge Galvanized Steel Framing
A S T E E L
E O F M I N
AN INTRODUCTION TO
RESIDENTIAL STEEL FRAMING
Why Use Steel Framing?....................................................2
This publication is intended as a guide for
home builders, developers, engineers and users
of light gauge steel framing (LSF) in residential
Manufacturing and Design................................................3
applications. LSF products are cold formed
structural members for applications such as
studs, purlins, rafters, joists and for use in such
Steel framing Components...............................................4
constructions as steel roof trusses and
panelized wall assemblies.
The CSSBI would like to acknowledge the
support and assistance provided by the
American Iron and Steel Institute in the
Stick Built Construction
creation of this document. The growth of
residential steel framing is spreading
throughout North America and the AISI is a very
Joining & Fastening...........................................................7
active supporter of this effort. The CSSBI and
the AISI cooperate on many issues of joint
concern to everyone's benefit.
Fire & Acoustic Performance............................................9
The material presented in this publication has
been prepared for the general information of
Residential Steel Framing Case Studies.........................11
the reader. While the material is believed to be
technically correct and in accordance with
recognized good practice at the time of
publication, it should not be used without first
securing competent advice with respect to its
suitability for any given application. Neither the
C S S B I
Canadian Sheet Steel Building Institute nor its
Copyright © December 1994
Members warrant or assume liability for the
suitability of the material for any general or
Canadian Sheet Steel Building Institute
All rights reserved. This publication, nor any part thereof,
may not be reproduced in any form without the written
permission of the publisher.
C S S B I
AN INTRODUCTION TO RESIDENTIAL STEEL FRAMING
Residential steel framing members were originally
For more than 150 years, steel has been used in the
designed as a substitute for wood framing. However,
North American construction market. Today it remains they are now being manufactured in systems which
one of the strongest, most durable and economically
reflect the superior strength and consistency of steel.
manufactured materials. While it has typically been
The variety of available steel shapes, strengths and sizes
associated with skyscrapers and bridges, steel is
has expanded beyond that of standard lumber, and this
emerging as the material of choice for residential
versatility offers the advantage of savings in both material
framing. Across Canada and the United States, builders, cost and time while delivering a consistently high quality
developers and homeowners are finding out about the
many benefits that steel has to offer in the residential
Environmental and economic concerns have prompted
the building industry to research alternative building
Although the name "steel" may conjure up images of a
materials and methods. This, in addition to its
heavy or cumbersome material, the coated steel
construction benefits and excellent recycling capabilities,
products used in residential framing are just the
is making steel framing a growing choice for residential
opposite. Cold formed sheet steel is a light weight, easy construction. This follows the long time use of steel
to handle, economical and high quality alternative to
framing in commercial construction where steel has
traditional wood framing materials. Among its other
proven quality and performance records.
advantages, steel offers the builder a strong,
dimensionally stable, easy to work with framing system.
was built in
steel wall studs
and floor joists in
construction site, at a central assembly point near the site
WHY USE STEEL FRAMING?
or can be assembled in panels at a factory. Steel gives a
The reasons why home builders are turning to steel framing
flexible response to nearly every home builder requirement.
members as replacements for wood are as varied as the homes • No heavy equipment is necessary when light gauge steel
they build. Here are some of the most significant benefits for
framing is used.
both user groups, the builder and the homeowner, that give
steel an edge over the competition.
“Steel framing was cheaper to install and featured
many labour saving components. This product is an
environmentally sound alternative to wood. It’s the
• Steel will not rot, shrink, swell, split, or warp and is
product that will lead the residential construction
industry into the next century.”
• Every steel stud is a good stud. There is no longer the
John Bruzzese, President
Armour Steel Framing Systems
need to sort through lifts of framing members to select
suitable pieces. Steel framing is of consistent quality.
"In working with steel framing the major differences
• Steel framing can be supplied to the exact lengths required
we found as a builder were the use of light weight
thus eliminating much of the on–site cutting and most of
materials, the various dimensional qualities, the use
of screw guns and cut off saws in lieu of hammers
and circular saws."
• Steel framing is a proven technology that is user friendly
Wayne Barry, President
allowing for a smooth transition from other materials.
Metallic Homes Inc.
St. Albert, Alberta
• Steel framing members are available in a variety of standard
shapes and sizes in varying steel thicknesses to
"As a builder of quality homes, it is important to us to
accommodate any structural requirements.
ensure that we are providing an excellent product at
a competitive price. Our experience with the
• Steel members weigh as much as 60% less than wood
Ancaster Homesteel project has shown us that steel
members; therefore, foundation and seismic loads can be
framing has a place in residential construction and
we plan to build more steel framed houses in the
• Steel framing members are manufactured with pre–punched
Robert Cooper, V.P. & G.M.
holes for running piping and electrical wiring, minimizing
Alterra Developments Ltd.
preparation work for other trades.
• Steel framing accommodates all types of commonly used
"I know this (steel framing) goes against the great
Canadian tradition of wood frame houses, but we
are convinced it's the house of the future."
• The inherent strength of steel can be utilized to reduce the
Joe Vella, V.P.
number of framing members required. It is not necessary to
Fifthshire Homes Ltd.
replace steel for wood stick–for–stick.
• Steel is competitively priced and consistent in quality. Steel
"Our commitment to LSF was brought about by the
vagaries of lumber quality, supply and pricing. The
prices are more stable than wood and steel supplies have
ability of the manufacturers to produce LSF
historically been more readily available.
members to required lengths, tolerances and
• Steel framing does not dry out and shrink over time, thus the structural quality, greatly reduces the waste factor in
the cost equation, in addition the decreased risk of
costly call backs to repair warped walls, nail–pops and
drywall problems due to the stability of LSF
squeaking floors are eliminated.
components further enhances the desirability of
• Building waste and pilferage from the construction site is
Peter J. Laughlin
Wessex Construction Management
• Steel members can easily be prefabricated at the
Shawnigan Lake, B.C.
• Workers can be easily trained to work with steel framing
• Steel framed walls are straight and remain that way. There
elements. Assembly details are easy for workers to quickly
is no shrinkage to cause nail–pops and squeaking floors.
• Steel framing has been used for decades in commercial and Environmental Benefits:
condominium construction. It is a tried and well proven
• All steel products are 100% recyclable. The overall
technology now available to home builders as an alternative
recycling rate of steel products in North America is 66%;
to wood framing.
the highest rate of any material.
• Job–site scrap has resale value.
• Steel products can be recycled repeatedly without
degradation or loss of properties.
• The steel industry is the single largest recycler in North
• Steel's inherent strength and non–combustible qualities
America because recycled steel is an integral ingredient in
enable a steel framed house to resist such devastating
events as fires, earthquakes, and hurricanes. Homes can be
designed to meet the highest seismic and wind load
specifications in any part of the country.
The NAHB Resource Conservation House in
Bowie, Maryland features steel framing.
• During the last decade, more than 1 trillion pounds of steel
Steel can accommodate distinctive
scrap have been recycled, keeping a valuable commodity
out of the country's landfill sites.
• Because of its strength, steel can span greater distances
• Magnetic separation makes steel the easiest and most
offering larger open spaces and increased design flexibility
economical material to remove from the solid waste
without requiring intermediate columns or loadbearing walls. stream.
• Remodeling can be easily accomplished. Non– loadbearing • The amount of energy needed to produce a ton of steel has
walls can easily be removed, altered and relocated.
been reduced by 34% since 1972 and continues to
• Steel framing does not need to be treated for termites. It is
free of resin adhesives and other chemicals used to treat
wood framing products.
• Steel framing can be used for every home style from
MANUFACTURING AND DESIGN
traditional to contemporary to ultra–modern and from low Steel framing members are manufactured by a cold forming
cost to luxury. Steel framed homes can be found in every process in which strips of coated sheet steel are put through a
series of roll forming dies which shape the sheet into the
desired profile, usually a "C" shape. The thickness of the
Standard CAN/CGSB–7.1 "Cold Formed Steel Framing
sheet can be varied to meet the structural requirements and
Components". This specifies minimum dimensions as well as
the length is cut precisely to order. The manufacturing
establishing material and structural requirements for
process automatically punches regularly spaced holes into the non–loadbearing, wind loadbearing and axial loadbearing
centre of the section to accommodate the installation of
members. For residential applications, the NBCC also
bridging and electrical or other services.
specifies other specific requirements that must be met.
The basis of cold formed steel design stems from the shape of
the cross–section. A flat sheet of thin steel is not very strong,
but when this sheet is formed into a "C" section, the bends act The coated sheet steel used in the manufacture of steel studs
as stiffeners and increases the strength of the sheet many
and joists must meet very specific material standards. Most
times over. Since most of the strength and stiffness of the
commonly, ASTM A653 standard specification for structural
section depends on the shape, not the thickness,
quality cold rolled sheet (replacing ASTM A446) is used to
strength–to–weight ratios are very favourable.
ensure the sheet steel is suitable for structural applications.
Steel is available in many different thicknesses and strength
levels. The common design thicknesses are 0.018, 0.033,
0.036, 0.044, 0.048, 0.060, 0.075, and 0.105 inches (exclusive of
any metallic coatings). It is important to specify sheet
thickness by the decimal thickness to guarantee a minimum
thickness of delivered product.
The sheet steel can be supplied in different strength levels to
meet the structural requirements of the project. In general,
for loadbearing product it is common to use material with a
yield strength of 33 ksi for thicknesses up to 0.048 inches. For
material in thicknesses 0.060 inches and greater, a 50 ksi yield
strength material is common.
The most common shape is the “C” section.
The material is also available with a number of different
The design of all cold formed steel structural products in
metallic coats needed for corrosion protection. A discussion
Canada is covered by the National Building Code of Canada
on corrosion resistance is presented in a later section.
(NBCC) where the CSA Standard S136 "Cold Formed Steel
Structural Members" is referenced. The design of these
The manufacturer of the steel framing products will specify in
structural members is well developed over many years of
their product literature the thicknesses and material strengths
research and development.
on which their load tables are based.
STEEL FRAMING COMPONENTS
Canadian manufacturers of light gauge steel framing follow a There is a cold formed steel framing component for virtually
number of standards to ensure the quality of the components any application. This variety allows for the simplification of
they produce meets the building code requirements. The
the framing system while providing maximum structural
standard used to specify these requirements is the CGSB
efficiency, design flexibility and ease of installation.
Construction elements of a framed house are divided into
joist spans. It is possible to increase the joist thickness to
three main assemblies: floors, walls and roofs. While these
span the long length of a room to open up the area between
assemblies are often consistent with wood framed
the joist to run the HVAC ducts. This can add to the head
construction, some steel assemblies may also involve new and room in basements without significant cost.
innovative framing systems.
The steel component known as the structural "C" is the
There are two basic types of steel studs: structural studs for
predominant shape. The greater strength of steel can offer
interior and exterior loadbearing walls, and drywall studs for
wider spacing between members and longer spans, a feature non– loadbearing interior partitions. The structural "C" studs
that makes for increased design flexibility as well as decreasing used in the wall construction range in size from 2–1/2 to 8
material and labour costs. Steel members can easily be spaced inches and in thicknesses from 0.033 to 0.071 inches. The
at 24 inches on centre.
drywall studs are available in sizes from 1–5/8 to 6 inches and
have thicknesses from 0.018 to 0.034 inches.
Generally, builders opt for joist depths ranging from 6 to 12
inches with a steel thickness from 0.034 to 0.101 inches.
Instead of using lapped joists on multiple span conditions, a
single length of joist can be used to span continuously.
However, a lap in the joist can be helpful in accommodating
the deviations in the concrete or masonry foundation walls
and for transportation.
Steel stud walls can be stick-built or panelized
Although 3–5/8 and 6 inch walls are common in stick–built
residential construction, wall thickness can be varied to meet
the structural and insulation requirements of the building.
Exterior rigid insulation is applied to the walls to minimize
thermal bridging and comply with building code
Steel floor joists are easily installed and can
span continuously across supports.
The broad range of available sizes and thicknesses allow steel
Floor joists can be supplied with knock–outs pre–punched
framing to be used in virtually any roof system, from the
into the webs at regular intervals. This will accommodate the simplest shed roof to the most complex hip and valley
installation of electrical and plumbing services.
construction. Trusses can be built on–site or off– site in truss
Another advantage of the range of steel joist thicknesses and plants, in complete or sectioned assemblies.
depths is in the flexibility it provides for the orientation of theCSSBI
• Sheet steel can be used as the sheathing material on
• Mouldings can be formed out of prefinished sheet steel
All of these systems have been used in Canada and illustrate
the innovations possible with steel while still complying with
current building code requirements.
There are three basic residential steel framing assembly
• Stick built construction
Roof framing can include steel
• Panelized systems
trusses or rafters.
• Pre–engineered systems
Stick Built Construction
It is easiest to consider the substitution of wood framing with Stick built construction is virtually the same in wood and steel.
steel framing because the two systems are essential
This framing method has actually gone through a
interchangeable. It is also possible to use steel in many of the transformation incorporating many of the techniques used in
other components of a house, for example:
panelized construction. The steel materials are delivered to
• The concrete foundation can be replaced with an insulated the job site in stock lengths or in some cases cut to length.
steel framed wall system.
The layout and assembly of steel framing is the same as for
• The asphalt shingles can be replaced with steel roof tiles or lumber, except components are screwed together rather than
steel roof cladding systems.
nailed. Steel joists can be ordered in long lengths to span the
• The traditional floor construction using joists and sheathing full width of the home. This expedites the framing process
can be replaced with a composite steel and concrete floor and eliminates lap joints. Sheathing and finish materials are
fastened with screws or pneumatic pins.
Basements can also be framed out of steel.
The Ancaster Homesteel Project utilized
stick-built construction methods.
materials. Engineered systems may space the primary load
carrying members more the 24 inches on centre, sometimes
Panelization consists of a system for prefabricating walls,
up to 8 feet. These systems use either secondary horizontal
floors and/or roof components into sections. This method of members to distribute wind loads to the columns or lighter
construction is most efficient where there is a repetition of
weight steel in–fill studs between the columns. Furring
panel types and dimensions. Panels can be made in the shop channels used to support sheathing materials also provide a
or in the field. Steel studs and joists are ordered cut to length break in the heat flow path to the exterior, which increases
for most panel work, placed into a jig and fastened by either
screws or welding. The exterior sheathing, or in some cases
the complete exterior finish, is applied to the panel prior to
Many of the pre–engineered systems provide framing
members which are pre–cut to length with pre–drilled holes
for bolts or screws. Most of the fabrication labour is done by
Shop panelization can offer several significant advantages to
the supplier, allowing a home to be framed in as little as one
the builder. The panel shop provides a controlled
environment where work can proceed regardless of the
weather conditions. Application of sheathing and finish
JOINING AND FASTENING
systems is easier and faster with the panels in a horizontal
Steel framing procedures are much the same as conventional
position. The panels are then transported from the panel
framing, using similar tools, but with different attachments.
shop to the job site.
The main tools used in steel framing are tin snips, a screw gun,
nibblers and a circular or chop saw. Construction workers
Amajor benefit of panelization is the speed of erection. A job who know how to use a power drill with a screwdriver
can usually be framed in about one quarter of the time
attachment will have no trouble with steel framing assembly.
required to stick–build. When you consider that the exterior Circular or chop saws are used for cutting steel by substituting
finish system may also be part of the panel, the overall time
abrasive wheels for wood cutting blades. It is as simple as that.
savings may be even greater.
Self drilling screws are the most common fastener used in
steel framing. These fasteners can be much more durable
This project in Ottawa was built up from
prefabricated panel assemblies.
With steel's high strength and design flexibility, innovative
Screwing is the most common means
systems are possible which are not possible using other
of connecting steel framing
than nails and can resist forces more effectively. It is
recommended that zinc plated or phosphate coated screws be
Everyone knows that steel left unprotected in the
used on exposed exterior surfaces. A wide variety of
environment will rust. This perceived drawback to steel has
self–drilling and self–tapping fasteners are available from local been addressed many years ago with the introduction of
construction material suppliers. Make sure that the proper
galvanizing. Galvanizing is the coating of the steel sheet with
screw is selected for the job.
alayer of zinc. More recently, another coating system that
uses an aluminum–zinc alloy coat (tradename Galvalume)
Aquestion often raised by trim carpenters is how to attach
has been introduced to the construction market.
interior trims and moulding to the steel frame. There are
many different methods to accomplish this easily. Around
The metallic coating (i.e. zinc, or aluminum–zinc alloy) has a
windows and doors, a wood trimmer piece can be framed into much lower corrosion rate than uncoated steel and protects
the rough opening. This trimmer simplifies the installation of the steel from the environment. The metallic coating will also
the window or door and provides a wooden member to fasten provide sacrificial protection to the steel.
trim pieces to. For baseboards, there are finishing screws
available that act the same as finishing nails. These screws
Metallic coated steel is designed not to rust while on the
have a small head that automatically countersink, ready to be construction site, during construction, or after construction.
Corrosion is inhibited first by the coating acting as a
protective barrier on the steel surface. This barrier
protection does not allow moisture to contact the steel:
without moisture there is no rusting.
Metallic coatings also protect the steel through sacrificial
action. If scratched or dented, the metallic coating will
continue to protect the exposed steel by sacrificial action.
The importance of the metallic coating to the service life of
the sheet steel is a key design criteria. Zinc or
aluminum–zinc alloy coatings are available in a range of
coating weights to suit different applications. The most
common coating specifications for residential steel studs are
Chop saws cut members to length.
G90 galvanized or AZ150 Galvalume.
Homeowners will also ask how they can hang a picture on a
steel stud. In the majority of cases, the desired location for a
picture never seems to line up with the location of a stud
In the colder climates of Canada and the northern United
(true in any type of construction). When this happens, the
States, providing the appropriate thermal resistance for a
picture is hung on the drywall using some type of common
building is an important design consideration. The following
toggle bolt or expansion anchor. When it is necessary to
points should be kept in mind.
fasten to a steel stud, it is simple to drill into the stud and
• Thermal bridging can be controlled by the addition of rigid
install a screw the same as in wood construction.
insulated sheathing on the cold side of the stud. This acts
as a thermal break which has been shown to provide
increased thermal resistance greater than just the added