Renovation 4th Edition

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Renovation 4th Edition Page 100

by Michael Litchfield

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

 

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