Renovation 4th Edition

by Michael Litchfield

departments require that plans

  and bathroom walls—especially those that will

  Basically, wood-frame walls are an array of

  be reviewed and stamped by a

  get cabinets or be tiled—and for corners, top wall

  licensed engineer before any sig-

  vertical studs nailed to horizontal top plates and

  plates, and jack studs along rough openings.

  nificant structural work is done.

  sole (bottom) plates. Depending on whether walls Pieces with slight bows (1⁄4 in. in 8 ft.) can be

  are bearing or nonbearing, plates may be dou-

  used as studs and joists, but draw an arrow on

  bled. Although 2x4 walls are by far the most com- the face of the lumber to indicate which way the

  monly framed, 2x6 walls allow thicker insulation

  lumber bows so you remember to place slightly

  and make routing pipes easier.

  bowed joists crown (bow) up, so they’ll be less

  likely to sag under weight. Set aside stock that

  Structural Carpentry

  183

  a ton of time. If possible, cut lumber or plywood

  right atop the stack that the lumberyard truck

  Work Safely

  delivered.

  Put first-aid kits and fire

  extinguishers in a central loca-

  nailing iT

  tion where you can find them

  On bigger projects, pneumatic nailers do most of

  quickly. Likewise, spend a lit-

  the work, but it’s worth knowing how to use a

  tle extra for safety equipment

  hammer correctly. Then you’ll create fewer bent

  that’s comfortable—safety

  nails, splits, and dings (dented wood when the

  glasses that won’t fog up, res-

  hammer misses the nail), and perhaps avoid a

  pirator masks that fit tight to

  smashed thumb, tendonitis, and joint pain.

  the face, hard hats that are

  The perfect swing. If you’re driving large nails

  strong yet lightweight, and

  such as 16d commons, start the nail with a tap.

  disposable work gloves flexible

  Then, with a relaxed but firm grip on the end of

  enough to grip small items. If

  the hammer handle, raise the hammerhead high

  safety equipment is not com-

  and swing smoothly from your shoulder. If you’re

  fortable, you won’t wear it. And

  assembling a stud wall, spread the pieces out on

  a deck, put one foot on the lumber to keep it in

  if you don’t wear it, it can’t

  place, bend forward slightly, and let the falling

  protect you.

  hammerhead’s weight do some of the work. Just

  before striking the nail, snap your wrist slightly

  to accelerate the swing.

  bows more than 1⁄4 in. in 8 ft., which you’ll cut

  However, if you’re driving smaller nails (6d or

  shorter and use as headers, cripple studs, and

  8d), you won’t need as much force to sink them.

  blocking. Return corkscrew (twisted) studs to the So choke up on the handle and swing from the

  lumberyard for credit.

  elbow. Choking up is particularly appropriate if

  you’re driving finish nails because you’ll need less

  Be methodical. Snap chalklines onto floors to

  force and be less likely to miss the nail and mar

  mark wall plates. Cut top and bottom plates,

  the casing. It’s also helpful to choke up when

  then mark stud locations and ROs for doors and

  there’s not enough room to swing a hammer freely.

  windows onto the plates. Make a cutting list: By

  cutting same-length lumber all at once you’ll save

  To nail in a hard-to-reach spot, start

  A blunted nail point is less likely to split wood because it

  A wood block under your hammerhead makes nail

  the nail by holding it against the side

  will crush the wood fiber in its path rather than wedge it

  pulling easier.

  of the hammer and smacking it into

  apart, as a sharp nail point does.

  the wood. Once the nail is started, you

  can finish hammering with one hand.

  184 Chapter 8

  zzzzzz loads and Structure

  Dead load (framing)

  Bearing wall

  Live load

  Point load

  Foundation

  Girder

  Soil and

  seismic loads

  Post

  Pad

  The right nail. The nailing schedule given in

  “Recommended Nailing Schedule” on p. 186

  NailiNg Plywood SheaThiNg

  suggests the size and number of nails you need

  for various framing tasks, but local building

  To nail plywood panels 1⁄2 in. thick or less, most codes specify 6d common nails

  codes will have the final say. When joining two

  spaced every 6 in. along the panel edges and every 12 in. in the field. Panels thicker

  pieces of framing lumber, nails should be long

  than 1⁄2 in. require 8d common nails spaced in the same pattern. (Structural shear

  enough to penetrate the second piece of wood,

  walls are typically nailed with 10d nails 4 in. to 6 in. on center along the edges and

  without sticking out the other side. Properly

  12 in. on center in the field, but an engineer should do an exact calculation.)

  sized nails also are less likely to split board ends.

  Don’t overdrive nails. Ideally, nail heads should depress but not crush the face ply

  As the table indicates, use two 16d nails to end-

  of the plywood. Panel strength isn’t affected if nail heads are overdriven by 1⁄16 in. or

  nail a stud through a plate, and four 8d nails,

  less, but if more than 20% of the nail heads are 1⁄

  which are shorter and skinnier than 16d nails, to

  8 in. or deeper, the Engineered Wood

  toenail stud ends to sole plates. To reduce split-

  Association (APA) recommends adding one extra nail for each two overdriven ones.

  ting, hammer nail points to blunt them before

  Pneumatic-nailer pressure that’s too high is the most common cause of overdriven

  driving them in.

  nails. It’s far better to set the nailer pressure so the heads are flush, and then use a

  single hammer blow to sink each nail just a little deeper.

  Assembling a wall on the ground is no guarantee that

  lumber edges will line up. Here, a builder uses his hammer

  to raise the top plate flush to the header before nailing.

  Wear safety glasses when using a pneumatic nailer.

  Structural Carpentry

  185

  removing nails. Everybody bends nails now

  and then, especially when nailing at an odd angle

  or in a tight space or nailing into a hard wood

  like southern pine. To remove a bent nail, slip a

  block under a claw hammer head to increase the

  leverage as you pull out the nail; if the nail

  head is buried too deep to grasp with a claw

  hammer, use a cat’s paw, which has pointed

  claws, to dig it out.

  recommended nailing Schedule*

  APPLIcATIon

  SchEDuLE

  Use a Speed Square to mark stud locations on a pressure-

  treated mudsill (sole plate) and a top plate. An X usually

  Joist to sill or girder
(toenail)

   3-8d

  indicates regular studs 16 in. on center; a J, jack studs; a

  K, king studs; and a C, cripple studs. The sole plate has

  ledger strip

   3-16d at each joist or rafter

  been predrilled so it will fit over the anchor bolts when the

  wall is assembled and lifted into place.

  16 subfloor or less to each joist (face-nail)

   2-8d (or 2-13⁄4 staples)

  wider than 16 subfloor to each joist (face-nail)

   3-8d

  laYing OuT wallS

  2-in. subfloor to joist or girder (blind-nail and face-nail)  2-16d

  Wall layout varies, depending on whether you’re

  erecting walls in open space (say, framing an

  Sole plate to joist or blocking (face-nail)

   16d at 16 in. o.c.

  addition) or within existing space (adding a par-

  tition). In both cases, use house plans to position

  Top or sole plate to stud (end-nail)

   2-16d

  walls. Snap chalklines onto subfloors (or floors)

  Stud to sole plate (toenail)

   3-8d or 2-16d

  to indicate the location of sole plates. If you’re

  building a partition, next measure from existing

  Sole plate to joists or blocking

   3-16d at 16 in. o.c.

  framing to determine the height and length of the

  new wall, as described in “Reinforcing and

  doubled studs (face-nail)

   10d at 24 in. o.c.

  Repairing the Structure” on p. 199. Finally, mark

  doubled top plates (face-nail)

   10d at 24 in. o.c.

  the locations of ROs, wall backers (blocking you

  nail drywall corners to), and studs onto plates.

  doubled top plates, lap-spliced (face-nail)

   8-16d

  The easiest way to frame a wall is to construct

  it on a flat surface and tilt it up into place. Once

  Continuous header, two pieces

   16d at 16 in. o.c. along each edge

  the wall is lifted, align the sole plate to a chalk-

  rim joist to top plate (toenail)

   8d at 6 in. o.c.

  line on the floor. This construction method is

  arguably stronger because you can end-nail the

  Ceiling joists to plate (toenail)

   3-8d

  studs to plates rather than toenailing them. End-

  nailing uses larger nails (16d) driven into the cen-

  Continuous header to stud (toenail)

   4-8d

  ter of each stud, which will better resist lateral

  Ceiling joists, laps over partitions (face-nail)

   3-10d

  forces on a wall. Toenailing better resists uplift,

  but the four smaller nails (8d) angled through the

  Ceiling joists not attached to parallel rafters (face-nail)  3-10d

  corners of stud ends are more inclined to split

  rafter to plate (toenail)

  the wood. These distinctions may be splitting

   2-16d

  hairs, however, because both methods are time-

  built-up corner studs

   10d at 24 in. o.c.

  proven. In any case, in renovation, there’s often

  not enough room to tilt up walls—which will be

  built-up girders and beams, 2-in. lumber layers

   10d at 32 in. o.c. at top and

  addressed later in this chapter.

  bottom and staggered; two

  nails at ends and each splice

  Mark rough openings. Place the sole plate, face

  up, next to a chalkline, then place a top plate next

  * From the international residential Code, 2009. (International Code Council [ICC], Washington, D.C.) to it so that edges butt together and the ends

  Reproduced with permission of the International Code Council. All rights reserved.

  align. Use a square to mark the top plate and the

  sole plate at the same time. (If the top plate is

  186 Chapter 8

  doubled, there’s no need to mark the upper top

  plate.) Using a tape measure, mark the ROs for

  doors and windows. Rough openings are so

  Doubled

  named because they are roughly 1 in. taller and

  zzzzzz Stud-wall elements

  top plate

  wider than prehung doors or windows (so frame

  jambs can be shimmed snug), and thus 2 in.

  Cripple studs

  taller and wider than unframed units.

  (“dragon’s teeth”)

  As you mark the width of the RO on the

  plates, keep in mind that there will be a king stud

  P R O T I P

  (full length) and a shortened jack stud (also called

  a trimmer stud) to support the header on each

  when partitions run perpen-

  side of the opening. After marking the ROs, mark

  dicular to the joists, center the

  the corner backers (also called wall backers)—

  studs over the joists whenever

  Doubled

  extra blocking for drywall where partitions

  2x6 header

  possible. aligning studs and

  intersect with the wall you’re framing. “Corner-

  joists creates straight, open

  Stud Layouts” on p. 188 shows several backer

  channels from floor to floor, so

  configurations.

  plumbers and electricians can

  Jack stud

  easily drill through plates and

  Mark studs on the plates. After marking the

  or trimmer

  run wires and pipes. Partitions

  first stud, which is flush to the end of the plates,

  that ran parallel to and directly

  mark the subsequent studs 3⁄4 in. back from the

  over the joists would be a big

  red 16-in.-interval highlights on your measuring

  King stud

  problem if you needed to run

  tape. (In other words, mark stud edges at 151⁄4 in.,

  wires or pipes. instead, consider

  311⁄4 in., 471⁄4 in., and so on.) By marking stud

  moving the partition 1 in. to 2 in.

  edges 3⁄4 in. back, you ensure that stud centers

  to avoid the joist.

  will coincide with the edges of drywall or sheath-

  ing panels, which are usually some multiple of

  Sole

  16 in., for example, 48 in. by 96 in.

  (bottom) plate

  Mark studs every 16 in. on center on plates—

  through the ROs as well—so that drywall or

  If you use doubled 2x6s for your header in a

  sheathing panels running above or below open-

  rough opening in standard 8-ft. wall framing,

  ings can be nailed to cripple studs at regular

  you need cripple studs to support the doubled

  intervals. At window openings, you’ll mark crip-

  top plate. If you use a 4x12 instead, it will

  ple studs on both the top and the bottom plates.

  support the top plates. Although code may al ow

  But on door openings, you’ll mark cripple studs

  a single top plate for nonbearing walls, a single

  on the top plates only. Note: For door openings,

  plate offers little to nail drywal to if the ceilin g

  where 16-in. on-center studs occur within 2 in. of

  is finished before the wall.

  a king stud, omitting the 16-in. on-center stud

  will not weaken the structure.

  Head
erS

  Every opening in a bearing wall must have a

  Standard

  header over it, and it’s common practice to put

  FraMiNg

  headers in all openings in exterior walls, whether

  For standard 8-ft. wall framing, cut studs

  bearing or not. Headers for 2x4 walls are usually

  921⁄

  constructed by sandwiching a piece of 1⁄

  2 in. long—or you can buy them as “pre-

  2-in.

  CDX plywood between two pieces of 2x lumber;

  cuts.” one bottom plate and two top plates will

  as 2x lumber is actually 11⁄

  be roughly 41⁄2 in. thick, creating a wall height

  2 in. thick, the header

  package is thus 31⁄

  of 97 in. This height accommodates one drywall

  2 in. thick—the same as the

  width of a nominal 2x4 on edge. Headers must be

  panel (1⁄2 in. to 5⁄8 in. thick) on the ceiling and

  able to carry a cumulative load and transfer it

  two 4-ft.-wide drywall panels run horizontally

  downward without flexing or pulling away from

  on the wall. If you install a 4x12 header directly

  the sides of the opening. Thus headers must be

  under the top plates of a standard wall, the

  sized according to the loads they carry and the

  rough opening height will be 821⁄2 in. This is just

  distances they span.

  right for a 6-ft. 8-in. door, and door head

  That noted, many builders use this rule of

  heights will match that of the windows.

  thumb when sizing headers for single-story build-

  ings with 2x4 walls and a 30-lb. live load on the

  Structural Carpentry

  187

  roof: The nominal depth a 4x header in inches

  equals the span in feet of the opening.

  oversizing headers. Span tables establish mini-

  zzzzzz Stud layouts

  mum requirements. In the field, however, many

  STUD-AND-PLATE LAYOUT

  builders often oversize headers—using 4x12s,

  say, to span all exterior openings—because it’s

  Mark stud edges on plates so that stud centers

  quicker than building header “sandwiches” from

  will be spaced 16 in. on center (o.c.).

  two pieces of lumber and plywood between.

  Distances (o.c.)

  48 in.

  Plus, you don’t need to cut dragon’s teeth, the

  short cripple studs between a header and the top

  16 in.

  16 in.

  16 in.

  plate. Quicker it may be, but it’s an extravagant

  use of wood and it increases thermal bridging

  (see p. 192). That noted, oversize headers have

  some advantages: