fastener used
thickness (in.)
length (in.)
wood studs,
Type W drywall screws
3⁄8, 1⁄2, 5⁄8
1, 11⁄8, 13⁄8
ceiling joists, rafters
(coarse thread)
(penetrate framing 5⁄8 in.)
wood studs only
Ring-shank drywall nails
3⁄8, 1⁄2, 5⁄8
1, 11⁄8, 11⁄4
light-gauge metal framing
Type S drywall screws
3⁄8, 1⁄2, 5⁄8
3⁄4, 7⁄8, 1
(fine thread)
MATERiAlS
drywall adhesive but, in truth, any adhesive that
meets ASTM C-557 standards will do just fine.
This chapter began with sizes and types of dry-
Joint tape is used to reinforce drywall seams and
wall. Now let’s look at screws, joint tape, corner
is available as 2-in.-wide paper tape and 11⁄2-in.-
beads, and joint compound before planning and
or 2-in.-wide fiberglass mesh tape. Self-adhesive
estimating supplies.
mesh tape is popular because it’s quicker. You
Drywall screws have all but replaced nails. Here can apply it directly to drywall seams and then
are the three principal types:
cover it with joint compound in one pass. With
Type W screws have a coarse thread that
paper tape, however, you must first apply a layer
grips wood well. They should be long enough
of joint compound, press the paper tape into it,
to penetrate framing at least 5⁄8 in. In double-
and apply a coat of compound over that. If there’s
layer installations (two panels thick), use
not enough compound under paper tape, it may
type W screws at least 1⁄2 in. long.
bubble or pull loose.
Type S screws have fine threads and are
Still, some professionals swear by paper tape
designed to attach drywall panels to light-steel
because it’s less expensive and stronger than
framing and steel-resilient channels. At least
fiberglass mesh, and it’s less likely to be sliced by
3⁄8 in. of the screw should pass through metal
a taping knife. It won’t stretch, and it is lightly
studs, so 1-in. type S screws are commonly
creased up the middle, making it easier to install
used for single-ply 1⁄2-in. or 5⁄8-in. drywall
and align in an inside corner. Consequently,
installations. If you’re attaching drywall to
many pros use mesh tape only with setting-type
heavy-gauge (structural) steel, use self-
compounds, which cure harder and stronger
Fiberglass-mesh joint tape isn’t as
tapping screws.
than drying-type compounds, described
strong as paper tape, but it sticks
directly to the drywall—without a bed
Type G screws are sometimes specified to
on p. 428.
of joint compound—so it’s faster to
attach the second panel of a fire-rated, double-
However, self-adhesive mesh is perfect for
apply. Use mesh tape only with
layer installation. That is, the first panel is the
drywall repair. If you press the mesh over a crack setting-type compound.
substrate to which the second panel is screwed
or small hole, you may be able to hide the prob-
and glued with construction adhesive. Ideally,
lem with a single layer of joint compound.
screws also should penetrate framing, so ask
Corner beads and trim beads finish off and
building inspectors about installation
protect drywall edges. They’re available in metal,
requirements if your local code specifies
PVC, and paper-covered variations. Most attach
type G screws.
with nails or screws.
nails are still used to attach corner bead and to
Corner beads are used on all outside corners to
tack panels in place. Ring-shank drywall nails
provide a clean finish and protect otherwise vul-
hold the best in wood; don’t bother with other
nerable drywall corners from knocks and bumps.
nail types. Nails should sink 3⁄4 in. into the wood. (As noted earlier, inside corners are formed with
just tape and compound.) Corner beads come in
Construction adhesive enables you to use fewer a number of different radii; larger bullnose vari-
screws and provides peace of mind for those
eties give you a dramatic curve. Whatever type
screws that miss the mark—ones that catch only
part of a stud or that are overdriven. You can buy
Finish Surfaces
427
drying-type compound. And, once opened, it will
keep for a month if you seal the bucket tightly.
Setting-type joint compounds, which contain
zzzzzz Corner and Edge Treatments
METAL CORNER BEAD
FLEXIBLE VINYL BULLNOSE
plaster of paris, are mixed from powders. They
Flexes to accommodate
set quickly, allowing you to apply subsequent
out-of-square corners.
coats before the compound is completely dry. In
Width varies; 11/8 in. is
general, they bond better, shrink less, and dry
common for use with
1/2-in. drywall.
harder than drying types. They harden via a
chemical reaction, hence their nickname, “hot
mud.” Depending on additives, they’ll set in
30 minutes to six hours. However, setting-type
compound sets up so quickly and so hard that it
can be a monster to sand. Once it’s mixed, you’ve
got to use it up. It won’t store.
Unless you’re a drywalling whiz, use a pre-
mixed, all-purpose, drying-type joint compound.
A 5-gal. bucket will cover 400 sq. ft., roughly, a
J-BEAD
L-BEAD
12-ft. by 12-ft. room with 8-ft. ceilings. The com-
pound is ready to use right out of the bucket. It’s
reasonably strong, and each application should
Thickness of
dry in a day.
drywall
One further distinction: Drying-type and
setting-type joint compounds are further formu-
Front flanges
lated as either taping compounds—used for the
will be taped
first coat, in which you embed the tape—or top-
and coated.
ping compounds, used for the second and third
coats because it feathers out (thins) better and
dries faster. Again, all-purpose compound can be
used for all three coats, but you might want to
experiment with the two types once you’ve had
you choose, though, install it in one piece—that
some practice. Some pros use setting-type joint
is, as a continuous strip from top to bottom.
compound for the first and second coats and dry-
J-beads keep exposed ends of drywall from
ing type for the third (and last) coat.
abrading. These beads are typically used where
panels abut tile or brick walls, shower stalls, or
P R O T I P
plANNiNg THE jOB
&
nbsp; openings that won’t be finished off with trim—
Before estimating materials, walk each room and
in other words, where the edge of the drywall is
Store premixed joint com-
imagine how best to orient and install panels.
pound at room temperature
the finished edge. L-beads are similar; they’re
These five rules, known to drywall pros, will save
(60°F to 70°F) so it’s ready to
used where panels abut windows, suspended
you a lot of pain.
apply. At lower temperatures, it
ceilings, paneling, and so on. In general, L-beads
doesn’t spread as easily. Never
are easier to install on panels already in place.
Rule 1: Use the longest panels possible. This
allow it to freeze; throw it out if
J- and L-beads are sized to drywall panel thick-
minimizes the number of joints. A 4-ft. by 14-ft.
it does because it won’t bond
ness; some types require joint compound but
or 4-ft. by 16-ft. panel is heavier and more
well after freezing. Added tip:
some don’t.
unwieldy than a 4-ft. by 8-ft. panel. But hanging
Store self-adhering mesh tape in
Flexible arch beads often come in rolls that are larger panels is relatively fast compared with the
a plastic bag so its adhesive
presnipped, so as you unroll them, they assume
time it takes to tape, coat, and sand the joints of
won’t dry out.
the shape of the arch you’re nailing or stapling
the smaller panels.
them to. Apply joint compound and finish them
Rule 2: Think spatially. Running panels hori-
as you would any drywall seam.
zontally—perpendicular to studs and ceiling
Joint compounds can be broadly divided into
joists—can reduce the number of joints and pro-
drying types and setting types. They differ in ease mote stronger attachments. For example, two
of use, setting (hardening) time, and strength.
4-ft. by 12-ft. wall panels run horizontally will
Drying-type joint compounds are vinyl based
reach an 8-ft. ceiling and create only one hori-
and dry as water evaporates from them. They
zontal seam to be filled. Two 54-in.-wide (41⁄2-ft.)
usually come premixed and are easy to apply and panels run horizontally will reach a 9-ft. ceiling.
sand. Typically, you can apply a second coat
However, if ceilings are higher than 9 ft., you
24 hours after the first, if you maintain a room
may be able to reduce the number of joints by
temperature of 65ºF. There’s little waste with
installing wall panels vertically (parallel to studs).
428 Chapter 15
Rule 3: Minimize butt joints. Long edges of
panels are beveled to receive tape joints, but the
short edges (butt edges) are not. Consequently,
19 ft.
butt joints are difficult to feather out, and they
zzzzzz Minimizing Drywall joints
are likely to crack. So try to minimize the num-
ber of butt edges. Where you can’t avoid them,
16-ft. panel
3-ft.
position them away from the center of a wall or
panel
ceiling. Last, always stagger (offset) butt joints in
8 ft.
adjacent panels; never align them. Otherwise,
you may need to feather joint compound out 3 ft.
to get a barely acceptable joint.
Butt joint
Butt joint
Rule 4: install drywall that’s thick enough.
Panels that are too thin may sag between ceiling
joists and bow between studs. For example, if
Joints = 27 lin. ft.
you’re running panels parallel to ceiling joists
spaced 24 in. on center, 5⁄8-in. drywall is much
19 ft.
stronger and less likely to sag than 1⁄2-in. panels.
Alternately, you can use lightweight drywall pan-
els (see p. 423), which sag less because they
weigh less: a 1⁄2-in. UltraLight Panel, for example,
can span ceiling joists spaced 24 in. on center
without sagging.
8 ft.
Rule 5: Don’t scrimp when ordering. Expect a
certain amount of waste, especially if you’re
installing around stairs or sloping ceilings. It’s a
mistake to try to piece together remnants
because that creates a lot of butt joints and looks
Joints = 32 lin. ft.
awful. Likewise, scrimping on screws or joint
Panel ripped to 3 ft. wide
compound results in weak joints and screw pops.
ESTiMATiNg MATERiAlS
Hanging wal panels horizontal y often reduces the number and length
of the joints. With studs a standard 16 in. o.c., you could reduce the
Start by consulting local building codes. They’ll
total lineal feet of taping by running panels horizontally instead of
specify the type, thickness, and number of
vertically. For the room dimensions shown, however, the upper layout
drywall layers you must install throughout
also creates two butt joints, which can be tedious to feather out.
the house.
It’s possible to estimate drywall materials
from a set of blueprints, but even the pros prefer
to walk the job, measuring walls and ceilings and
Calculating Drywall Square Footage
noting where using longer panels will minimize
square
joints. By using this technique, you get exactly
panel
feet
the panel lengths you need.
length
per
number
total
As you walk through the rooms, record your
(ft.)
panel*
of panels
square feet
findings on graph paper with 1⁄4-in. squares. Use
one sheet of paper per room, letting each square
8
32
40
=
1,280
equal 1 ft. Then, when your materials arrive,
you’ll know which room gets what.
9
36
35
=
1,260
1. Measure the width and length of each room.
10
40
30
=
1,200
In general, think in 2-ft. increments. That is, if a
wall is 10 ft. 6 in. long, plan to buy 12-ft. panels
12
48
25
=
1,200
and run them horizontally to get the fewest
14
56
20
=
1,120
joints. If studs aren’t spaced a standard 16 in. on
center, note that on your graph paper. (If you’re
16
64
20
=
1,280
not sure of stud and joist spacing, use a stud
total
finder.) Calculate the number of panels of each
7,340
dimension you’ll need for each room.
* Calculations assume that all panels are 4 ft. wide.
Finish Surfaces
429
2. Note door and window locations and
4. Note the direction and spacing of ceiling
dimensions, but don’t deduct their square footage joists. Panels run perpendicular to ceiling joists
from the room total. Portions of panels cut out
(or rafters, if a cathedral ceiling) are less likely
for windows and doors will yield a high percent-
to sag.
age of non-factory edges, so it’s easiest to discard
5. Consider special rooms. Install paperless or
this scrap or piece it together in out-of-way places, moisture-resistant drywall in laundry rooms,
such as closets.
behind kitchen sinks, and in bathrooms other
3. Note the ceiling height. If the ceiling is 8 ft., than in tub/shower areas. Cover tub/shower areas
two standard 4-ft. by 8-ft. wall panels run hori-
with cementitious board if they’ll be tiled. Install
5
zontally will reach it; if they’re 9 ft. high, use two
⁄8-in. type X or type C drywall on shared walls
horizontal 54-in.-wide panels. If ceilings are
between the garage and living space. If existing
higher than 9 ft., you may want to rent scaffold-
plaster is in bad shape and you don’t want to tear
ing and a drywall lift.
it out, cover it with 1⁄4-in. or 3⁄8-in. drywall.
6. Take into account special features, which
include arches, curved stairwells, barrel ceilings,
odd nooks, built-in bookcases or cabinets, and
the like. For curves, you need flexible 1⁄4-in. dry-
zzzzzz Estimating Drywall Needs
CEILING
wall. Expect a lot of waste around complex areas,
Joist direction
such as stairways.
Four 12-ft. panels
7. Think about maneuverability. In older
homes, especially those with narrow stairs, there
may not be room to maneuver extralong panels.
WALLS
If you’re replacing windows, you may be able to
have a boom truck deliver panels through win-
Four 16-ft. panels
Three 12-ft. panels
dow openings, but only if the truck can get close
One 10-ft. panel
to the house. In short, anticipate how you’ll bring
11 ft. 6 in.
drywall into the house. In extreme cases, you
Window
may need to use shorter panels for some rooms.
Two 16-ft. panels
Inquire about options with your drywall supplier.
Door
8. Once you’ve figured out how much drywall
12-ft. panel
you need for each room, figure out where you’ll
store it. If possible, distribute drywall throughout
Renovation 4th Edition Page 100