Renovation 4th Edition

by Michael Litchfield

  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