The company I work for in southern Wisconsin specializes in
commercial construction. Many of our jobs see us partitioning
the interiors of office buildings, manufacturing facilities,
and other professional spaces. Fire codes require the use of
noncombustible materials in commercial spaces, so light-gauge
steel framing is the way to go. While steel currently
represents only a tiny percentage of residential framing, the
rising price of lumber may yet change that equation. In this
article, I’ll limit the discussion to nonbearing interior
partitions; structural steel framing typically requires
engineering and is a separate focus.
A Case for Steel
Most residential carpenters have little experience with steel
framing and may be leery of adopting an unfamiliar material.
However, if you’re thinking about testing the waters, the
good news is that little is required in the way of specialty
tools — you probably already own most of them. The
framing techniques are somewhat different, but with a little
training, production rates can be comparable to wood
Steel studs are rot- and termite-proof and are galvanized to
resist corrosion. They’re also about 60 percent lighter
than their wood counterparts, which reduces installer fatigue.
The studs are uniformly straight and dimensionally consistent,
making plumbing and lining walls a snap. Walls framed with
steel are flat and true and they stay that way. And since the
studs don’t shrink, twist, or hold moisture, drywall
screw pops are unlikely. The studs come with prefabricated
knockouts, which simplifies horizontal wiring and plumbing
runs. Finally, steel is an endlessly recyclable material; steel
studs typically contain at least 25 percent recycled
Studs and Track
Metal studs are available in sizes to match wood framing and
in a range of gauges for various applications. The basic
nonstructural C-channel stud is made from 25-gauge steel and is
suitable for nonbearing partition work (see Figure
1). For a stiffer wall or one taller than 10 feet, a
heavier 20-gauge stud can be substituted. (You can find wall
height tables for nonbearing walls at the Steel Stud
Manufacturers Association Web site, ssma.com, and more
extensive information in Section R603 of the IRC).
Figure 1. Getting the hang of framing with
light-gauge steel studs just takes a little experience. Steel
and lumber have different structural properties, but stud sizes
and layout are the same (above). Deep-leg U-channel can
compensate for out-of-level conditions — allowing all
studs to be cut to a common length — or contain
square-cut studs on raking walls (left).
Studs are specified by size and minimum thickness. The web and
flange dimensions are expressed in hundredths of an inch,
followed by a “STUF” letter describing the
component section (“S” for stud, “T”
for track, “U” for U-channel, “F” for
furring) and then the metal thickness, expressed in thousandths
of an inch. Thus, a 3 5/8-inch 25-gauge stud with a 1 1/4-inch
flange may be designated “362S125-18.”
Note that gauge numbers don’t match thickness numbers,
as in this example, where 18 is used to designate a 25-gauge
stud. Furthermore, the thickness within a gauge designation is
allowed to vary within a certain range, and thicknesses can
vary considerably from one manufacturer to the next. Specifiers
typically refer to thickness, not gauge, when selecting steel
Standard U-channel — which we call “track”
on the job — has 1 1/4-inch flanges and serves in place
of the top and bottom plates used in wood framing. Studs fit
inside the track, which is nailed or screwed directly to the
floor and the ceiling. Deep-leg track gives a little more
coverage for special applications.
Ordering steel. Calculating quantities is really no
different from doing a wood framing takeoff. There are distinct
wall types, some extending to the roof deck, some to the bottom
of the bar joists, and others only to the existing suspended
ceiling grid (Figure 2). Specifications should
provide the appropriate size, gauge, and stud spacing —
typically 16 inches on-center — for any given job. Most
supply houses stock 8-, 9-, 10-, 12- and 16-footers, with
special-order lengths taking only a few extra days to obtain.
If you need custom lengths, or if you need 100 studs of a
particular length, you can order them precut, saving time and
labor on site. I once ordered precut 26-foot-tall 20-gauge
studs to partition a factory interior; we were dividing a
painting area from open office space.
Figure 2. In commercial framing, nonbearing
partitions may extend to the underside of the roof deck (left)
or only to the bottom of the bar joists (right), each of which
calls for a different fastening method.
Tools for Steel Framing
When it comes to cutting studs heavier than 25-gauge, a
dedicated metal-cutting chop saw is a must (Figure
3). A decent 14-inch model will set you back only
about $200. (It’s not safe to use a wood-cutting miter
saw to cut steel, because of its high rpm.) There are two types
of blades used to cut steel: abrasive blades and the newer
carbide-tooth blades specifically made for cutting ferrous
metal. Abrasive blades throw more sparks than toothed blades
do, but at $9 apiece versus $130 for a carbide blade, we use
them exclusively. With a 14-inch chop saw, you can cut a full
bundle of studs to length before cutting the banding — a
considerable time saver. When an abrasive blade is worn to the
point where it can no longer cut completely through a bundle,
we toss it.
Figure 3. A 14-inch metal-cutting chop saw is handy
for gang-cutting bundled studs and mandatory for cutting
heavier 20-gauge steel members.
Gloves. We always wear them. Cut channel edges can be
razor sharp. Lightweight cloth gloves with a rubberized coating
on the palms are best (Figure 4).
Figure 4. Inexpensive rubberized cloth gloves keep
hands from getting sliced on razor-sharp cut edges. Here, a
short slit in the end of one track prepares it for mating with
Snips. A good pair of straight-cutting sheet-metal
snips sees routine use on our jobs, trimming studs and cutting
flanges to make tab-style header and blocking connections (more
on this later). The going gets rough in steel heavier than
20-gauge; in fact, 20-gauge steel will wear out a pair of snips
pretty quickly. I like the yellow-handled pro-series Wiss snips
Also, while you don’t really need them,
it’s still nice to have right- and left-cutting pairs
handy in your toolbox for the rare occasion.
Clamps. Vise-type locking C-clamps, commonly used in
metal fabrication, are indispensable in steel framing.
They’re used to temporarily hold a stud or section of
track in place during leveling and can prevent materials from
shifting while you install a screw. Irwin locking C-clamps
are smooth-acting and reliable and are sold in various throat
depths, including a long-throat model that sometimes comes in
very handy (Figure 5).
Figure 5. A fundamental tool collection
covers most steel framing tasks.
Screw gun. One tool most steel-framing experts recommend
is a 2,500-rpm clutch-drive VSR screw gun. It’s used both
to connect framing members and to fasten the drywall. Using
drywall guns — which run at 4,000 rpm and higher —
is generally not advisable, since they spin too fast and will
strip a screw before it fully penetrates the steel.
If you don’t like dragging a cord around, cordless screw
guns run at a suitably low rpm and can do the job. For 25- to
20-gauge framing, any 14-volt or higher tool is adequate, but
an impact driver provides a slight advantage in helping the
screw to penetrate the steel.
Laser. For laying out, plumbing, and straightening
walls, a self-leveling rotating laser is essential. The
self-leveling feature ensures that if the laser is jostled, the
line will recover its accuracy rather than provide a false
Usually, the stud supplier will also supply the screws used to
connect steel framing members (Figure 6).
These are self-tapping 1/2-inch pan-head sheet-metal screws,
the type with an integral drill tip that can penetrate 20-gauge
steel. We use self-piercing coarse-thread drywall screws to
connect 25-gauge steel studs to existing walls, screwing them
right into the drywall. Once drywall is hung on the new
framing, there’s no danger of lateral movement and so no
need to connect to the existing framing. Of course, we also use
drywall screws to attach the drywall to the studs. As a rule,
you want to use a screw long enough to leave a minimum of three
threads protruding through the steel.
Figure 6. Various fasteners are needed to connect
steel to itself and to building surfaces. Clockwise from left:
Self-drilling screws are the standard for framing-to-framing
connections. Self-piercing screws are effective in light,
25-gauge materials. Powder-actuated pins — typically
1„2-inch and 3„4-inch sizes —
connect framing to hard concrete decks and structural steel
beams. Tapcon concrete screws anchor steel door frames to
concrete floors, and mushroom anchors serve in applications
where pins may not hold as well.
Hard-surface nailers. We do a lot of fastening to
steel beams, masonry walls, and concrete decks. On big jobs,
our primary tool for this is a TrakFast TF1100 (800/241-5640,
ramset.com), basically a
high-powered cordless nail gun capable of shooting 1/2-inch to
1 1/2-inch pins into steel and concrete (Figure
7). The TrakFast is much faster than a powder-actuated
tool (PAT) and holds 42 pins in the magazine, four times that
of most PATs. It costs about $475, including a battery and
charger; pins come in boxes of 1,000 along with a fuel cell for
about $60. If we need to drive longer pins or need more power
to penetrate hard concrete or thick steel beams, we use a Hilti
Figure 7. A TrakFast gas-powered nailer can outshoot
a PAT in many applications, and it handles pins up to 1
1„2 inches long. The author’s crew relies
heavily on this tool when fastening bottom tracks to the
Mushroom-head anchors. In hard, brittle concrete, a
mushroom anchor provides better holding power than a 1/2-inch
pin. The anchors come in nylon and lead versions; lead
definitely holds better in concrete. On smaller jobs,
hammer-drilling the necessary holes is fast enough, so we skip
Stud crimper. This tool isn’t mandatory, but it
can come in handy for fastening studs where a screw gun
can’t go. Malco’s model PL1 (800/328-3530,
is the best one we’ve tried. It’s rated for
22-gauge steel and runs about $60.
Crimping can’t completely replace screwing, however,
since the connection isn’t as secure. When the drywall is
hung, the screws briefly deflect the stud flange and can force
the crimp apart. And with heavier-gauge studs, the crimper
simply isn’t capable of penetrating the steel.
It’s a good idea to check local building codes, too.
Some inspectors require 100 percent screwed connections.
The first step in framing walls is to snap the layout on the
floor. Spraying it with clear lacquer preserves the chalk
lines. To avoid walking or driving over the bottom plate while
fastening the top plate, we install all of the top plates
first. (The technique of framing a wall on the deck before
standing it up is rarely used with steel. Unless you weld the
studs to the track, you can’t attach both sides of the
studs while they’re lying down. Even if you could, metal
studs are not rigid like wood studs, so the assembly would
still be twisty and likely to collapse on itself when
Because the ceilings are typically complicated by ductwork,
beams, and bar joists, we don’t lay out stud locations on
the tracks before installing them.
To place the ceiling track, one worker moves a vertical laser
along the floor lines while another fastens the track. If
we’re fastening to corrugated-metal roof decking, we use
self-tapping stud screws (Figure 8). If the
deck is poured with concrete (as in multiple-story buildings),
we shoot pins. If the walls are over 12 feet tall and
we’re working from a scissor lift, we put all of the
track, fasteners, and other supplies right in the basket.
Figure 8. Self-tapping screws provide a fast, secure
connection to steel roof decking. If the decking is capped with
concrete, the author shoots pins instead.
At corners, it isn’t necessary to cut the track to exact
length. Just run the first piece a little long, then snip the
inside flange at the return point and hammer the excess flat.
The return track can then overlap the first and complete the
corner (Figure 9).
Figure 9. Outside corners are simply snipped and
overlapped. Corner studs are connected only to the track
flanges — not to each other.
Slip track. Snow loads on large commercial roofs can
cause the ceiling to deflect within its design tolerance.
Nonbearing partitions must be designed to accommodate this
movement. A slip track is a deep-leg track that allows the
studs to be cut shorter than full height to accommodate
periodic ceiling deflection. Since the studs can’t be
screwed to the track, they are crimped. The crimp will fail
before the wall buckles. (You can use screws to temporarily
hold the stud in place until the drywall is installed and
secures the studs.) You also have to leave about a 1-inch
clearance gap between the drywall and the underside of the
ceiling. The gap can be concealed by a piece of trim attached
to the ceiling only.
Hollow Metal Door Frames
In our work we install more hollow metal Ceco (888/264-7474,
cecodoor.com) door frames
than any other type. These frames are installed before the
bottom track and the studs. Once the frames are anchored in
place, you run the bottom track and attach the steel studs
directly to the door frame (Figure 10). Welded
frames ship with temporary tack-welded steel angle spreaders
that keep the jambs aligned during installation. After the
drywall’s installed, you chop them out with a cold
Figure 10. The author drills holes for mushroom
anchors to secure a hollow metal door frame. Note the magnetic
level at the head jamb (left). Plastic shims under the side
jambs are used to level the head (middle). Integral tabs in the
frame’s side jambs provide connection points for the
trimmer studs (right).
First, we stand the frame on layout and level the head,
inserting plastic shims under either leg as needed. The side
jambs have welded anchor tabs at the base for securing the
frame to the floor with Tapcon concrete screws (877/489-2726,
mushroom-head anchors. Coarse-thread wood screws work on
plywood decks. A frame will stand on its own once it’s
anchored to the floor, so we don’t add temporary bracing.
Later, when the drywall’s installed, we plumb the frames.
I’ll explain this later.
Once the top track and the door frames are set, we cut and
fasten the bottom track to the floor (Figure
11). I typically use mushroom anchors placed 4 inches
in at either end and on 4-foot centers. If we’re shooting
3/4-inch pins, we space them at 2 feet on-center, since they
don’t have the holding power of the anchors. We make sure
the track is fastened down securely at door openings and
corners. Then we add the layout marks for stud spacing
(typically 16 inches on-center), window openings, and cabinet
locations where blocking is required. For marking on steel,
which can be oily, a black Sharpie works best.
Figure 11. The bottom track is installed after all
door frames are set. If shooting pins, the author uses a closer
on-center schedule than when using mushroom anchors, which have
better holding power in brittle concrete.
Steel studs are rotated into position in the installed track
and plumbed, one at a time. Always keep the open side of the
studs facing the origin of your layout; this ensures that at
vertical joints, the drywaller screws the first panel to the
more flexible open leg of the stud (Figure
12). This is important because drywall screws push the
flange away before piercing it and pulling it back snug. If a
panel has already been attached to the stiffer web edge of the
stud, the screws driven into the floppier open end may not
fully retrieve the flange, leaving a misaligned surface and
Figure 12. Always face the open side of steel studs
toward the origin of the layout. This ensures that at butt
joints screws driven into the first panel will pull the
flexible stud flange tight to the board, resulting in a flat
wall finish (top). In the field, place screws closer to the
stiffer web face of the stud (bottom).
When cutting door and window cripples, remember to cut all
studs from the same orientation so the prepunched holes will
match up. We save offcuts for bracing and patching; at the end
of the job, all of the scrap goes to a sorting company for
The track flanges provide a little play, so it isn’t
necessary to cut every stud to exact length. If the floor or
the ceiling is slightly out of level, you can cut all the studs
to the shortest dimension. If there’s a large discrepancy
in level, a deep-leg top track can cover the difference.
With the top and bottom track installed, we stand all the full
studs in the track, skipping over door and window locations and
anywhere there’s an obstruction, like an overhead beam or
hvac duct. These places require a header and cripple
Headers. Nonstructural headers are sections of track
cut to the desired length plus 4 inches for an attachment tab.
We snip across the flanges 2 inches in from both ends, fold the
web back at a 90-degree angle, and slip the flanges over the
stud (Figure 13). Then we level the header and
hold it in place with locking clamps while we screw the flanges
to the stud.
Figure 13. Nonstructural headers are made quickly by
snipping channel flanges at the desired distance and folding
the ends down (left). The channel tabs are then screwed to the
trimmer studs (right).
Plumbing door frames. At door locations, we screw the
trimmer studs directly to welded tabs on the hollow metal
frame, centering the frame in the wall plane and making sure
that the drywall can slip between it and the stud on both sides
of the wall (Figure 14). On walls 12 feet or
taller, we install double trimmer studs. This stiffens the wall
at these locations and keeps it from rattling when the door is
slammed. When we hang the drywall, it slips past the stud about
3/8 inch behind the hollow frame. We then plumb the frame and
screw the drywall to the trimmer studs. The drywall holds the
door frame plumb.
Figure 14. Trimmer studs are connected directly to
the hollow door frames with self-tapping screws. The drywall
slips between the stud and the frame and holds the door frame
Interior finish work often requires plywood blocking to
provide a nail base for trim or extra holding power for hanging
cabinets and heavy-duty shelving (Figure 15).
If the job calls for prehung wood doors, we frame rough
openings and line them with framing lumber to catch the
Wood backers provide holding power for
hanging cabinets and heavy-duty shelving (top). For prehung
wood doors, rough openings are formed conventionally and lined
with framing lumber to supply a nailing surface (bottom).
For applications like coat hooks or small shelving units that
don’t need extra holding power, it’s okay to screw
directly into the studs. When running narrow wood base trim, we
use light nailing in combination with construction adhesive.
You can shoot 16-gauge finish nails straight into
single-thickness 20-gauge steel, but steel won’t hold
nails like wood does. For wide baseboard profiles, we install
plywood backers and rely on nails alone.
Brad Caspari is a project superintendent for Hunzinger
Construction in Brookfield, Wis.