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COLLEGE OF ARCHITECTURE AND PLANNING
Department of Architecture and Building Sciences
ARCH 436
Contemporary Building Construction Methods
10. LIGHT-GAUGE STEEL FRAMING
Dr. Mohammed Ghonim
Lecture Objectives
Upon completion of this lecture, the student will be able to:
1. Explain the concept of light-gauge frame construction.
2. Discuss the advantages and disadvantages of light-gauge frame construction.
3. List the types of light-gauge frame construction.
4. Describe the contraction process of light-gauge frame construction.
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Lecture Content
•
Introduction.
•
Historical Brief.
•
Applications of Light-gauge Steel Framing.
•
Cold Forming Process.
•
Steel Galvanization.
•
Advantages & Disadvantages of Lightgauge Framing.
•
Light-gauge Steel Members.
•
Light-gauge Steel Joist Floors.
•
Light-gauge Steel Stud Walls.
•
Light-gauge Steel Rafter Roofs.
•
Framing Process.
•
Finishes for Light-gauge Steel Framing.
•
Electrical & Plumbing Installations.
•
Tools
Used
Construction.
in
Light-gauge
Steel
Introduction
Light gauge steel construction is the noncombustible equivalent of wood light frame
construction. The external dimensions of the standard sizes of light gauge members
correspond closely to the dimensions of the standard sizes of nominal 2-inch (38-mm)
framing lumber.
These steel members are used in framing as closely spaced studs, joists, and rafters in
much the same way as wood light frame members are used, and a light gauge steel frame
building may be sheathed, insulated, wired, and finished inside and outside in the same
manner as a wood light frame building.
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Historical Background
The use of cold-formed steel members in building construction began in the 1850s in both
the United States and Great Britain. In the 1920s and 1930s, acceptance of cold-formed steel
as a construction material was still limited because there was no adequate design standard
and limited information on material use in building codes. One of the first documented uses
of cold-formed steel as a building material is the Virginia Baptist Hospital, constructed
around 1925 in Lynchburg, Virginia. The walls were load bearing masonry, but the floor
system was framed with double back-to-back cold-formed steel lipped channels. In the 1940s,
Lustron Homes Company, built and sold almost 2500 steel-framed homes in America, with
the framing, finishes, cabinets and furniture made from cold-formed steel.
Virginia Baptist Hospital
Lustron Homes
Applications of Light-gauge Steel Framing
Light-gauge (Cold-formed) steel framing refers specifically to members in light-frame
building construction that are made entirely of steel sheets, formed to various shapes at
ambient temperatures. The most common shape for light-gauge steel is a lipped channel,
although “Z”, “C”, tubular, “hat” and other shapes and variations have been used. The
building elements that are most often framed with cold-formed steel are floors, roofs, and
walls, although other building elements and both structural and decorative assemblies may
be steel framed.
In high-rise commercial and multi-family residential construction, light-gauge frames are
typically used for interior partitions and support of exterior walls and cladding. However, in
many mid-rise and low-rise applications, the entire structural system can be framed with
light-gauge steel members.
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Cold Forming Process
In building construction there are basically two types of structural steel: hot-rolled steel
shapes and cold-formed steel shapes. The hot rolled steel shapes are formed at elevated
temperatures while the cold-formed steel shapes are formed at room temperature. Coldformed steel structural members are shapes commonly manufactured from steel plate,
sheet metal or strip material. The manufacturing process involves forming the material by
either press-braking or cold roll forming to achieve the desired shape.
Cold Forming Process
Cold-formed steel (CFS) is the common term for products made by rolling or pressing thin
gauges of sheet steel into goods, cold-formed steel members are created by the working of
steel sheets using stamping, rolling, or presses to deform the sheet into a usable product.
Cold-formed steel products are commonly used in all areas of manufacturing of durable
goods like appliances or automobiles but the phrase cold form steel is most prevalently
used to described construction materials.
Cold-formed steel construction materials differ from other steel construction materials
known as hot-rolled steel. The manufacturing of cold-formed steel products occurs at room
temperature using rolling or pressing.
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Steel Galvanization
Galvanization is the process of applying a protective zinc coating to steel or iron, to
prevent rusting. The most common method is hot-dip galvanization, in which parts are
submerged in a bath of molten zinc.
Although galvanizing will prevent attack of the underlying steel, rusting will be expected,
especially if exposed to the natural acidity of rain. For example, corrugated iron sheet
roofing will start to degrade within a few years despite the protective action of the zinc
coating. Marine and salty environments also lower the lifetime of galvanized steel because
the high electrical conductivity of sea water increases the rate of corrosion primarily
through converting the solid zinc to soluble zinc chloride which simply washes away.
The Advantages & Disadvantages of Light-gauge Framing
Advantages
Disadvantages
Like wood light framing: flexible, simple to construct,
and accept the same interior and exterior finishes.
Readily conducts heat and requires extra attention to
eliminating thermal bridging effects.
Noncombustible.
Members require more frequent bracing.
Lighter weight, so it is an advantage in seismic zones
Although it is galvanized, it is subject to corrosion.
Less waste and recyclable.
More expensive, specially in the labor part.
Steel is not subject to fungal decay or termite attack.
Conducts electricity if not well isolated.
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Light-gauge Steel Members
For studs, joists, and rafters, the steel is formed into C-shaped sections. The webs of
cee members are punched at the factory to provide holes at 2-foot (600-mm) intervals; these
are designed to allow wiring, piping, and bracing to pass through studs and joists without the
necessity of drilling holes on the construction site. For top and bottom wall plates and for
joist headers, channel sections are used.
The strength and stiffness of a member depend on the shape and depth of the section and the
gauge (thickness) of the steel sheet from which it is made.
A standard range of depths and gauges is available from each manufacturer, but commonly
used metal thicknesses for loadbearing members range from 2.46 mm to 0.84 mm, and are as
thin as 0.45 mm for nonloadbearing members.
Light-gauge Steel Joist Floors
Light-gauge steel joists are
manufactured by cold-forming
sheet or strip steel. The
resulting steel joists are lighter,
more dimensionally stable, and
can span longer distances than
their wood counterparts, but
conduct more heat and require
more energy to process and
manufacture. The cold-formed
steel joists can be easily cut
and assembled with simple
tools into a floor structure that
is lightweight, noncombustible,
and damp proof.
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Light-gauge Steel Joist Floors
As in wood light frame construction,
the framing contains cavities for
utilities and thermal insulation and
accepts a wide range of finishes.
Light-gauge Steel Joist Floors
The web stiffener is an important piece in
light-gauge steel floors that is inserted
inside the joist and screwed to its vertical
web to help transmit wall loads vertically
through the joist.
Web Stiffener
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Light-gauge Steel Stud Walls
Light-gauge steel studs are manufactured by cold-forming sheet or strip steel. The coldformed steel studs can be easily cut and assembled with simple tools into a wall structure
that is lightweight, noncombustible, and damp proof. Metal stud walls may be used as
nonloadbearing partitions or as bearing walls supporting light-gauge steel joists. As in wood
light frame construction, the stud framing contains cavities for utilities and thermal insulation
and accepts a wide range of finishes.
Light-gauge Steel Stud Walls
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Light-gauge Steel Stud Walls
Typical detail of the anchorage of a cold-formed steel bottom track to the foundation.
Light-gauge Steel Stud Walls
Detailed view for a CFS stud wall
Hold-downs
Tilt-up construction is used for building stud walls
Horizontal bracing
Diagonal bracing
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Light-gauge Steel Rafter Roofs
Detail at ridge.
Because assemblies are prefabricated, roof framing is in the form of trusses. Being lighter
than corresponding wood trusses, cold-formed steel trusses can generally be hoisted into
position without special lifting and hoisting equipment.
Additionally, the joints between members of a cold-formed steel truss are more rigid, so that
the trusses are easier to handle and more forgiving during their placement.
Light-gauge Steel Rafter Roofs
Typical eave detail
The depth of light gauge steel roof trusses is
usually based on the desired roof pitch. A typical
depth is one quarter of the width (span) of the
building.
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Framing Process
The sequence of construction for a building that is
framed entirely with light gauge steel members is
essentially the same as for a building framed with
nominal 2-inch wood members.
Framing is usually constructed with the platform
method; the ground floor is framed with steel joists.
Mastic adhesive is applied to the upper edges of the
joists, and wood panel subflooring is laid down and
fastened to the upper flanges of the joists with
screws. Steel studs are laid flat on the subfloor and
joined to make wall frames.
The wall frames are sheathed either with wood panels
or, for noncombustible construction, with gypsum
sheathing panels, which are similar to gypsum
wallboard but with glass mat faces and a waterresistant core formulation. The wall frames are tilted
up, screwed down to the floor frame, and braced.
The upper-floor platform is framed, then the upper
floor walls. Finally, the ceiling and roof are framed in
much the same way as in a wood-framed house.
Prefabricated trusses of light gauge steel members
that are screwed or welded together are often used to
frame roofs.
Finishes for Light-gauge Steel Framing
Any exterior or interior finish material that is used in wood light frame construction may be
applied to light gauge steel frame construction.
Whereas finish materials are often fastened to a wood frame with nails, only screws may be
used with a steel frame. Wood trim components are applied with special finish screws,
analogous to finish nails, which have very small heads.
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Electrical & Plumbing Installations
The above pictures show the electric and plumbing installations for CFS buildings and the accessories used.
Tools Used in Light-gauge Steel Construction
Screw Gun
Power Saw
Torched Cutter
Power Shear
Tin Snips
Power Riveting tool
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Summary
•
•
•
•
•
Light gauge steel construction is the
noncombustible equivalent of wood
light frame construction.
Light-gauge (Cold-formed) steel framing
refers specifically to members in lightframe building construction that are
made entirely of steel sheets, formed to
various
shapes
at
ambient
temperatures.
CFS framing resembles wood light
framing in many aspects as; it is
flexible, simple to construct, and accept
the same interior and exterior finishes.
CFS framing is more advantageous than
wood light framing in many aspects as;
it is noncombustible, Lighter in weight, less in
waste, recyclable, and it is not subject to
fungal decay or termite attack.
The sequence of construction for a building
that is framed entirely with light gauge steel
members is essentially the same as for a
building framed with nominal 2-inch wood
members.
References

Allen, Edward & Lano, Joseph (2009) Fundamentals of Building Construction: Materials and
Methods, John Wiley & Sons.

Ching, Francis (2008) Building Construction Illustrated, John Wiley & Sons.

Mehta, Madan et. al. (2013) “Building Construction”, Pearson, USA.

http://en.wikipedia.org

http://youtube.com
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Lecture Activity
Each student is required to prepare a brief but informative internet-based research about one of the topics
related to this lecture (Light-gauge Steel Framing) Timber Construction); i.e., new developments, successive
and local case studies or important details. The research should be presented in only one A4 sheet.
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