regular drywall.
durable and cost-effective. Mortar is the premier
Access to work areas. Using sheets longer
substrate for tiling, but it takes a skilled hand to
than the basic 8 ft. reduces the number of end
do it right.
joints that need taping. But these jumbo 14-ft.
Paperless drywall was developed in response to
and 16-ft. panels are practical only if your doors
concerns about mold. Organic matter such as
and stairwells are large enough to admit them.
paper or lumber is a food source for mold, so by
Regular drywall comes in four thickness (1⁄4 in.,
replacing paper facing with fiberglass mats,
3⁄8 in., 1⁄2 in., and 5⁄8 in.) and in sheets 8 ft. to 16 ft. paperless drywall resists the growth of mold,
long in 2-ft. increments. There also are 4-ft. by
even in basements, kitchens, bathrooms, and
9-ft. sheets. To minimize wall joints when install-
other areas of high humidity. Although paperless
ing drywall horizontally, regular drywall comes
drywall can be installed with basically the same
in 48-in. and 54-in. widths.
tools and techniques used to install regular dry-
The most commonly used thickness is 1⁄2 in.,
wall, paperless panels are somewhat more fragile
typically installed over wood or metal framing. A
and the dust more irritating. Taping, cutting, and
sheet that size weighs about 60 lb., still manage-
sanding these panels is slightly different, as
able for a strong installer working solo.
described on p. 439.
To increase fire resistance and deaden sound,
Fire-resistant drywall (type X or type C) is spec-
you can double up 1⁄2-in. panels, but that may be
ified for furnace rooms, garages, common walls
overkill. More often, a single layer of 5⁄8-in. dry-
between garages and living spaces, and shared
wall is used for that purpose. Being stiffer, 5⁄8-in.
walls in multifamily buildings. To make type X
panels are harder to damage, so they’re also a
drywall panels stronger under fire conditions,
smart idea in hallways if you’ve got kids. And
manufacturers add glass fibers to the gypsum
they’re less likely to sag between ceiling joists or
core. Type X drywall is available in a thickness of
bow between studs.
5⁄8 in., widths of 48 in. and 54 in., and lengths up
Renovators commonly use 1⁄4-in. and 3⁄8-in.
to 16 ft.
sheets to cover damaged surfaces and thereby
Type C has greater heat-resistive qualities
avoid the huge mess of demolishing and remov-
because, in addition to glass fibers in its core, it
ing old plaster. For best results with this thin dry-
also contains vermiculite, a noncombustible
wall, use both construction adhesive and screws
material. Type C is available in 1⁄2-in. and 5⁄8-in.
422 Chapter 15
thicknesses and in the same widths and lengths
as type X drywall. Both types of fire-resistant dry-
wall are installed like regular drywall. To achieve
a one-hour fire rating for single-family residences,
most codes specify 5⁄8-in. fire-resistant drywall.
USG Sheetrock UltraLight Panels weigh
roughly 40 lb. for a 1⁄2-in.-thick 4x8 panel, as
opposed to the 60 lb. for regular drywall panels
of the same size. Less weight also means less sag,
so you can confidently hang a 1⁄2-in. UltraLight
panel on ceiling joists or rafters spaced 24 in.
on center—instead of the 5⁄8-in.-thick drywall
usually specified for ceilings. Scoring, cutting,
attaching, and finishing these panels is the same
as installing regular drywall except, of course,
they’re easier to lift. For non-fire-rated uses,
1⁄2-in. panels are available in standard widths
and lengths to 16 ft. Fire-rated 5⁄8-in. panels also
are available.
Basic drywall tools. Top: drywall
Cutting and shaping tools may be simple, but
hammer, utility saw, and rasp.
Other specialty panels are available. Foil-backed they must be sharp. Drywall can be cut with one Bottom, from left: 6-in. taping knife, drywall is sometimes specified in the Frost Belt
spackling knife, utility knife, multibit
pass of a sharp utility knife, a quick snap of the
to radiate heat back into living spaces and prevent
screwdriver, chalk, and chalkline box.
panel, and a second cut to sever the paper back-
moisture from migrating to unheated areas.
ing, as shown in the top center photo on p. 434.
Abuse-resistant drywall, sound-mitigating drywall Buy a lot of utility-knife blades and change them
(see p. 448), and vinyl- and fabric-covered panels
often; dull blades create ragged edges. Use a
with prefinished edges are also manufactured.
Surform® rasp to clean up cut drywall edges. The
Blueboard is a base for single- or two-coat
sharp point of a drywall saw enables you to
veneer plastering and is now widely used instead
plunge-cut in the middle of a panel without drill-
of metal, wood, or gypsum lath. It is available in
ing, although the edges of the cut will be rough.
standard 4-ft.-wide panels.
A drywall router or a laminate router with a
Gypsum lath is specified as a substrate for tra-
drywall bit is the pro’s tool of choice for quick,
ditional full-thickness, three-coat plastering. Its
clean cuts around electrical outlet boxes, ducts,
panels are typically 16 in. by 48 in.
and the like. With a light touch and a little prac-
Cementitious backer board has a core of
tice, you can use this tool to cut out boxes
cement rather than gypsum. Used as a tile sub-
already covered by drywall panels, as shown in
strate, it is installed much like drywall (see chap-
the bottom photo on p. 434. Typically, a standard
ter 16 for details).
1⁄8-in.-dia. drywall bit is used on boxes and ducts,
whereas a 1⁄4-in. drywall bit is used to trim excess
TOOlS
drywall around windows and doors. Note: The
You can install drywall with common carpentry
larger bit creates an exponentially greater
tools—framing square, hammer, tape measure,
amount of dust.
and utility knife. Still, a few specialized, moder-
ately priced tools will make the job go faster
and look better. If you’ve got high ceilings, rent
scaffolding.
Stilted PeRFORMAnCeS
Layout tools include a 25-ft. tape measure,
for taping and sanding, some pros swear by
which will extend 8 ft. to 10 ft. without buckling;
stilts, but they’re awkward and ill advised for
a 4-ft. aluminum T-square for marking and cut-
ting panels; a chalkline for marking cutlines lon-
amateurs. already off-balance from working over
ger than 4 ft.; a compass or a scriber to transfer
your head, you could easily fall backward and
out-of-plu
mb wall readings to intersecting pan-
injure yourself. for that reason, stilts are
els; and a 2-ft. framing square to transfer the
banned by many state regulatory agencies and
locations of outlet boxes, ducts, and such onto
excluded from workers’ insurance coverage.
the panels.
Finish Surfaces
423
For 8-ft. to 9-ft.
ceilings, benches
can support
platform planks
and enable
workers to raise
and attach
The VAniShinG Nail
panels easily.
drywall screws can be installed faster than dry-
wall nails. they also hold better and are less
likely to damage a panel’s paper facing. ring-
shank nails are often used to tack up panels, but
screws take over from there. besides, screws are
quiet and nonconcussive, so installers are less
likely to disturb finish surfaces, tottering vases,
or feisty next-door neighbors.
Adjustable drywall benches should enable you
to reach 8-ft. or 9-ft. ceilings easily. Alternately,
you can lay planks across sturdy wooden
sawhorses.
Ultimately, renting a drywall lift and/or scaf-
Alternately, you can use a utility saw to cut out folding is the safest way to go, especially if ceil-
the waste portion of a drywall panel that you’ve
ings are higher than 10 ft. If there’s no danger of
run long into a doorway or window opening.
falling off your work platform, you can focus on
attaching drywall. Scaffolding is also indispens-
Lifting tools will help get drywall panels up into able during the taping and sanding stages.
place so they can be attached. Two lifting tools
can be handmade: A panel lifter inserted under
Attachment tools are typically a corded screw
the bottom of a panel will raise it an inch or so,
gun or a drill with a Phillips screw bit to drive
leaving your hands free to attach the drywall.
drywall screws. A cordless drill is fine for dry-
Metal panel lifters are not expensive, but 1x2
walling a single room, but pros who have thou-
scraps work almost as well.
sands of screws to drive prefer corded screw
The second homemade tool, a T-support, tem-
guns, which have clutches and depth settings
porarily holds a panel against ceiling joists while
that set the screw heads perfectly—just below the
you attach it. Cut a 2x4 T-support about 1⁄2 in.
surface. That may change, however, as cordless
longer than the finished ceiling height so you can drivers continue to improve battery life and add
wedge it firmly against the panel. Or you can rent useful features. The Senco® DuraSpin® shown on
an adjustable stiff arm, a metal version of a 2x4
the facing page uses collated fastener strips that
T-support.
contain enough screws to install a panel.
A panel lifter leaves your hands free
to attach the drywall panel.
Drywall router (bottom) and screw gun.
424 Chapter 15
A mud pan holds enough joint
compound to cover hundreds
of screw holes or several long
panel joints.
This Senco DuraSpin 14.4v driver employs a clutch to
prevent overdriving screws, as well as a collated strip of
fasteners that frees up one hand to hold a drywall panel
in place.
Pros also use a drywall hammer for incidental blades 10 in. to 24 in. wide; a 12-in.-wide knife
P R O T I P
nailing. A standard carpenter’s hammer will do
will suffice for most jobs. Trowels have a handle
almost as well, but the convex head of a drywall
roughly parallel to the blade and a slightly curved
New taping knives and trowels
hammer is less likely to damage the paper facing
blade that “crowns” the compound slightly.
may have burrs or sharp corners
of a panel.
Trowel blades run 8 in. to 14 in. long.
that can tear the drywall’s paper
A caulking gun also is an essential tool. More
Applying “mud” (joint compound) takes
facing. Before you use a new
and more, drywall installers are using construc-
finesse, so most pros use a mud pan or a hawk to
tool, sand the edges and corners
tion adhesive to attach drywall panels—whether
hold enough mud to tape several joints. As they
lightly with very fine emery
to decrease the number of screws they need, to
work, drywallers are constantly in motion: scoop-
paper. Rinse these tools repeat-
improve sound attenuation, or anytime it’s neces-
ing mud, centering it on the knife blade, scraping
edly with warm water as you
sary to install a double layer of drywall.
off the excess, and returning it to the pan or onto
work, dry them when you’re
the hawk.
done, and store them apart from
Taping and finishing tools are used to apply
Corner knives enable you to apply mud to both
heavy tools so their blades won’t
joint compound to the seams between panels.
sides of an inside corner simultaneously. To fin-
get nicked.
The workhorse of taping is the 6-in. taping knife,
ish outside corners (those that project into a
perfect for filling screw holes, spreading a first
room) consider making your own tool. Boil a
layer of joint compound, and bedding tape.
plastic flat knife, and once it’s soft, bend it into
To apply the successively wider and thinner
the shape you need, as shown in the photo below.
second and third coats of joint compound, you’ll
For high-volume jobs, you can rent taping
need wider taping knives or curved trowels.
tools that dispense tape and compound simulta-
Taping knives typically have straight handles and neously. See “Mechanical Taping Tools” on p. 439
for more information.
Wet
Left: a home-
-SAnDinG
bent knife for
shaping outside
using a large sponge to wet-sand drywall joints
corners. Right:
an inside-corner
will definitely reduce dust, but wet-sanding
knife.
isn’t feasible for a project of any size because
you must rinse the sponge and change the water
continually. also wet-sanding soaks the paper
facing, sometimes dislodges the tape, and tends
to round joint compound edges rather than taper
them. that said, if you’re drywalling a small
room and don’t like moving the furniture out of
the room, wet-sanding is a cleaner way to go.
Finish Surfaces
425
A dust-free sander attached to a shop
vacuum cuts dust dramatically, but in
unskilled hands it will oversand soft
topping coats.
Sponges and a pail of water will keep tools
A shop vacuum with a fine dust filter is a must;
clea
n as you go. Even tiny chunks of dried com-
vacuum at each break so you don’t track dust all
pound will drag and ruin freshly applied layers,
over the house. Dust-free sanding attachments
so rinse tools and change water often. A perfectly are available for shop vacuums (as shown in the
P R O T I P
clean 5-gal. joint compound container is a great
photo above). Although they virtually eliminate
rinse bucket. Use a second one to store and trans- dust, they’ll sand through soft topping coats and
Tape dispensers hold paper or
port delicate trowels and knives.
expose the joint tape in a flash if you’re not care-
mesh tape and clip to your belt,
ful. For best results, run them at low speed set-
so your tape is always ready to
Sanding equipment starts with special black
tings and use 220-grit sandpaper.
roll. Bigger dispensers hold a
carbide-grit sandpaper, which resists clogging; it
Finally, tape up sheet plastic in doorways to
500-ft. roll.
comes precut to fit the rubber-faced pads
isolate the rooms you’re sanding, especially if
attached to poles and hand sanders. Sandpaper
people are living in the house. Painter’s tape will
grit ranges from 80 (coarse) to 220 (fine); 120-grit do the least damage to trim finishes and paint.
paper is good to start sanding with. Finish-sand
with 220 grit or a rigid dry-sanding sponge (a spe-
cial sponge that is never wetted).
A sanding pole with a pivoting head enables
you to sand higher—8-ft. ceilings are a snap—
and with less fatigue because you use your whole
upper body.
Sanding joint compound generates a prodi-
gious amount of dust, so buy a package of good-
quality paper dust masks that fit your face tightly;
they’re inexpensive enough to throw out after
each sanding session. If you’re sanding over your
head, lightweight goggles and a cheap painter’s
hat will minimize dust in your eyes and hair. If
you’re working with paperless drywall, which has
fiberglass mats instead of paper facing, a dust
mask is essential, as are a long-sleeved shirt, gog-
Adjust your screw gun so that it dimples the surface of the
gles, and work gloves—fiberglass dust itches.
drywall but does not tear the paper facing.
426 Chapter 15
Drywall Fasteners
drywall
minimum fastener
attaching to...
Renovation 4th Edition Page 99