10-ft. panel
the house, stacking panels on the floor rather
8 ft.
than leaning them against walls, which can dam-
age their edges. In each room, anticipate the
sequence of installation—ceilings first!—so the
panels you need first will be accessible.
15 ft. 8 in.
9. Make a master list of all the drywall you
Two 12-ft. panels
need for the complete renovation.
Two 16-ft. panels
gETTiNg READy TO HANg DRyWAll
Here’s a final checklist before installing drywall:
The building should be dry and relatively
warm (between 60°F and 70°F). Keep
Same room, drawn flat,
temperatures constant. If a room becomes too
on graph paper
hot (80°F or higher), joint compound may dry
too quickly and crack. If the heating system is
inoperable, rent a portable heater. Ventilation
11 ft. 6 in.
also is important for drying: Drying-type joint
compound contains a lot of water.
Framing lumber must be dry: 15% to 19%
moisture content is optimal (see p. 59). Green
8 ft.
or wet lumber will shrink as it dries, causing
cracks and nail pops in a new drywall job;
don’t use it.
15 ft. 8 in.
430 Chapter 15
guesstimating Materials
Measuring each room is the only accurate way to develop an estimate of how
much drywall you’ll need. But a rough estimate of square footage can help you figure
about how much joint tape, joint compound, and fasteners you’ll need.
Add up the square footage of all rooms to be drywalled. For rooms with 8-ft. ceil-
ings, use a factor of 3.5 multiplied by the room length and room width. For example:
3.5 20 ft. 30 ft. = 2,100 sq. ft. of drywall. For rooms with 9-ft. ceilings, use a
factor of 3.85.
For each 1,000 sq. ft. of drywall, you’ll need approximately:
1,000 screws or nails (using construction adhesive reduces this total)
375 ft. of joint tape
11 gal. of premixed, all-purpose, drying-type joint compound
Note: if you use construction adhesive to reduce the number of fasteners, a standard
Metal drywall clips can help secure drywall edges in
10.5-oz. tube of adhesive will yield 15 lin. ft. of 3⁄8-in.-wide bead.
corners where there’s insufficient blocking.
Sight along studs and ceiling joists to see
around a work site is a two-person job. Both of
if they are aligned in a plane. To be more
you should be on the same side of the panel,
precise, stretch a taut string or hold a
same hand supporting the bottom edge, same
straightedge across the framing members.
hand balancing the top. (Imagine ballet dancers
Running drywall panels perpendicular to
in a line.) As you walk, lean the upper part of the
framing will help conceal minor
panel against your shoulder.
misalignments, as will textured finish
Hanging ceilings is definitely a two-person
surfaces. But it’s better to adjust misaligned
job, especially if you’re hanging long panels to
framing, especially if the drywall surface will
minimize joints. Once the two (or three) of you
be brightly lit or otherwise prominent. If a
tack up a ceiling panel, one of you can finish
stud is misaligned more than 1⁄4 in., your
attaching it, while another measures or cuts the
options include hammering it into line, power-
next piece.
P R O T I P
planing it down, and shimming up low spots,
Measuring isn’t difficult, but you need to be
as described in chapter 8.
aware of framing quirks. For example, if the
The square factory edge of a
Use a framing square to determine if
walls aren’t plumb where they meet in the cor-
drywall panel will not fit correctly
corners are square, and make sure there’s
ners, take at least two measurements so you’ll
when it abuts an out-of-plumb
blocking in the corners so you’ll have
know what angle to cut in the end of the panel
corner. Rough-cut the panel
something to attach the panel edges to. Or you
you’re installing. If the two readings vary only
about 1 in. long, position it
can use drywall clips to “float” the corners—
against the out-of-plumb wall,
slightly—say, 1⁄4 in.—there’s no need to trim the
and save lumber in the process.
and use a scriber (a student’s
end of the panel because taping and filling the
compass is fine) to transfer that
Install steel nail guards to protect
joint will take care of the gap. But if readings
angle to the face of the panel.
plumbing pipes and electrical cables within
vary more than 3⁄4 in., trim the panel end at an
Cut along the scribed line, and
11⁄4 in. of joist or stud edges. Few things are as
angle so there’s no gap where it abuts the out-of-
the panel should fit correctly.
frustrating as discovering a leak or an
plumb wall.
electrical short after the drywall is up. Then
Second, if you’re running panels perpendicu-
make a final check of the electrical outlet
lar to the framing, butt ends must meet over joist
boxes. They should be securely attached to the
or stud centers. If framing members aren’t evenly
framing with their edges flush with the drywall
spaced, you may occasionally need to trim a butt
face (see chapter 11).
end to make it coincide with a joist center.
Last, and most important, cut panels about
1
HANDliNg, MEASURiNg,
⁄4 in. short so you never need to force a panel
into place. Forcing will crush an end that you’ll
AND CUTTiNg DRyWAll
need to repair later. If it’s a ceiling panel, the gap
Handling drywall is a bit like waltzing: You can
will eventually be covered by wall panels that fit
do it by yourself, but it’s not all that much fun.
against it.
For starters, carrying a cumbersome 60-lb. panel
Finish Surfaces
431
Drywall over plaster
Drywalling over plaster is a cost-effective way to deal with plaster that’s too
dingy and deteriorated to patch or too much trouble to tear out. But this requires
1/4-in. drywall
some important prep work.
zzzzzz Trim Considerations
if you see discoloration or water damage, repair the leak or find a way to con-
1/4-in. drywall
trol excessive indoor moisture before attaching drywall.
Old plaster
locate ceiling joists or studs behind the plaster. Typically, framing is spaced
16 in. or 24 in. on center, but you never know with older houses. if ceiling joists are
Old plaster
exposed in the attic above, your task is simple. Otherwise, use a stud finder or drill
Cap molding
exploratory holes. Once you’ve located the joists or studs, snap chalklines on the
Cap molding
panels to indicate the centerlines you’ll use when driving screws.
Lath
Use screws and plaster washers to reattach loose or sagging plaster sections
before you install drywall. To minimize the number of fasteners, apply adhesive to
Lath
the back face of the drywall, and be sure the screws grab framing—not just lath.
Baseboard trim
plaster washers are shown on p. 443.
Baseboard trim
For ceilings, use 2-in. type W drywall screws, which should be long enough to
penetrate 3⁄8-in. drywall, 1 in. of plaster and lath, and 5⁄8 in. into joists. On walls,
1⁄4-in. drywall is a better choice because drywall shouldn’t sag, and thin drywall
doesn’t reduce the visible profile of existing trim as much. Otherwise, you may either
New drywall over old plaster can reduce the visible
need to build up existing trim or remove the trim and reinstall it over the drywall.
profile of existing molding it abuts so much that
New drywall over old plaster can reduce the visible
the molding looks undersize. In this case, you have
if there’s living space above the plaster ceiling, attaching resilient channel
profile of existing molding it abuts so much that
two alternatives: Use molding to build up (increase
may be a good move. These channels bridge surface irregularities and deaden sound.
the molding looks undersize. In this case, you have
the thickness of) trim where drywall abuts it. Or
Screw the channels perpendicular to the joists (see the top photo on p. 448). Then
two alternatives: Use molding to build up (increas
remove the trim and reinstall it over the drywall. e
screw drywall panels perpendicular to the channels.
the thickness of) trim where drywall abuts it. Or
remove the trim and reinstall it over the drywall.
Once you’ve cut a panel, snap parallel
chalklines across the face, indicating stud or joist
centers behind the drywall once it’s in place.
Guided by these lines, your screws or nails will
always bed into framing.
Cutting drywall is literally a snap if the blades in
your utility knife are sharp. Run the blade along
a drywall T-square or a framing square, if that’s
all you have. In one pass, score the paper cover-
ing. Grasp the smaller section and snap it sharply
away from the cut, breaking the gypsum core
along the scored line. Then cut through the paper
on the back side.
Cutting is usually easiest if you lean the panel
against a wall so you don’t need to bend over.
But if you’ve already stacked panels on the floor,
you can use them like a workbench, cutting them
in place.
Start by tearing off the end papers that join
pairs of panels face to face, allowing you to move
panels individually. In this manner, you’ll cut
every other panel from the back.
Most professionals would rather score the
Before hanging drywall, check that studs are plumb, corners are square, and (as shown) that studs
front face first, but it doesn’t truly matter which
align in a plane. If not, they must be built up with shims or planed down.
side you cut first, as long as your blade is sharp,
432 Chapter 15
your snap is clean, and you don’t rip or snag the
paper on the front face. If the gypsum edge is a
A Ripping GOOD TiMe
bit rough or the panel is a little long, clean up the
edge with a drywall rasp. But be careful not to
cutting along the length of a drywall panel—
fray the face paper.
ripping a panel—is fast and easy if you know
Making outlet box, switch, and duct cutouts
how. extend a tape measure the amount you want
can be done before or after you hang the drywall.
to cut from the panel. if you’re right-handed,
To make cuts before, measure from a fixed point
lightly pinch the tape between the index finger
nearby—from the floor or a stud, for example—
and thumb of your left hand to keep the tape
and transfer those height and width measure-
from retracting. your right hand holds the utility-
ments to the panel. A framing square resting on
knife blade against the tape’s hook. using your
the floor is perfect for marking electrical recepta-
left index finger as a guide along the edge of the
cles. That done, use a drywall saw to punch
panel, pull both hands toward you evenly as you
through the face of the panel and cut out the
walk backward along the panel. remember, the
opening, being careful not to rip the paper facing
blade needs only to score the paper, not pene-
as you near the end of the cut.
trate the core, so relax and keep moving.
That’s one way to do it. Problem is, the cutout
rarely lines up exactly to the box.
Using a drywall router is quicker and more
accurate. First, make sure the power is off, and
push any electrical wires well down into the box
so the router bit can’t nick them. The 1⁄8-in. dry-
wall bit should extend only 1⁄4 in. beyond the back
of the drywall.
Next, measure from a nearby stud or the
floor to the (approximate) center of the box, and
transfer that mark to the drywall. Then tack up
the panel with just a few nails or screws—well
away from the stud or joist the box is attached
to. Gently push the spinning bit through the
drywall, and move it slowly to one side until you
hit an edge of the box. Pull out the bit, lift it over
The screw (or nail) head should sink just
the edge of the box, and guide the bit around the
below the surface of the panel, without crushing
outside of the box in a counterclockwise direc-
the gypsum core or breaking face paper. You will
tion. This method takes a light touch—plastic
later fill the dimple around the head of the fas-
boxes gouge easily—but it’s fast and the opening
tener with joint compound.
will fit the box like a glove.
Screw spacing will depend on the framing inter-
Production drywallers often run panels over
val and whether you also use construction adhe-
door and window rough openings, then use a
P R O T I P
sive. Using adhesive reduces the number of
drywall saw or a drywall router with a 1⁄4-in.-dia.
screws or nails required. As shown in “Fastener
bit to cut the panels flush to the edges of the
When sizing screws or nails,
Spacing” on p. 434, if studs are spaced 16 in. on
opening (a 1⁄4-in. bit is less likely to break than a
see “Drywall Fasteners” on
center, a drywall screw every 16 in. will suffice,
standard 1⁄
p. 427. Fasteners that are too
8-in. bit). Wear safety glasses and a
whereas if you als
o use construction adhesive to
dust mask whenever you use a router.
short won’t support the panel
affix panels, space screws only every 24 in.
adequately. On the other hand,
Drywall edges are a bit fragile, so place screws
ATTACHiNg DRyWAll
fasteners that are too long
back at least 3⁄8 in. from panel edges. For best
are more likely to drive in
Most professionals use drywall screws exclusively, gripping, screw heads should be sunk just below
cockeyed or pop the drywall
although some use a few nails along the edges to
the surface of the panel, creating a dimple.
if the framing shrinks.
tack up a panel temporarily. Corner bead is often Screws driven deeper will tear the facing paper
nailed up, too.
and not hold as well. You can adjust a screw
When attaching drywall, push the panel firmly gun’s clutch to sink screws at a dimpling depth,
against the framing before driving in the screw.
but variations in the density of wood will prevent
Fasteners must securely lodge into a framing
you from doing so uniformly. Consequently, some
member. If a screw misses the joist or stud,
pros adjust guns to leave screw heads a bit proud,
remove the screw, dimple (indent) the surface
then drive each to a perfect dimple depth using
around the hole, and fill it later.
the cordless driver at a slower speed.
Finish Surfaces
433
CUTTIng DRywALL
2. Snap the panel sharply away from the face cut (here
hidden) to break the gypsum core along the scored line.
Then cut through the paper backing along the break.
3. If the cut is rough, clean it up with a drywall rasp.
nails follow the spacing guidelines in “Fastener
Spacing” except that you should double-nail in
1. In one pass, score the paper face
the field. Paired nails are 11⁄2 in. to 2 in. apart, so
of the panel using a utility knife
the center of each pair of nails is spaced every
guided by a drywall T-square.
16 in. on wall panels. Along panel edges, do not
double-nail. Instead, space single nails every 8 in.
Use ring-shank nails.
Using adhesives and screws has been likened
to wearing a belt and suspenders, but adhesives
do provide insurance if panels are problematic in
any way. When installing paperless drywall, for
example, it’s easy to overdrive screws—so adhe-
A drywall router quickly cuts out
Renovation 4th Edition Page 101