Book Read Free

Renovation 4th Edition

Page 47

by Michael Litchfield


  ically come in 2-in. by 100-ft.

  girder. For this reason, short sections “scabbed

  Existing studs

  rolls or bundles of 50 precut

  on” don’t work and are usually prohibited by

  strips 36 in. or 45 in. long. Cut

  local building codes.

  strips with a utility knife, and

  New studs

  To insert the new joist, remove blocking or

  attach them to the studs with

  bridging between the affected joists, and bend

  hammer tackers, using 3⁄8-in.

  over or snip off flooring nails protruding from

  staples. (Fortifiber® is one

  the underside of the floor. Then eyeball the new

  manufacturer.)

  sister joist and note its crown: If its arc is exces-

  sive, power plane it down so that you don’t bow

  up the floor as you drive the joist into place.

  Beveling the leading top edge of the joist will also

  make sledging into place easier. Once the new

  joist is in position, use bar clamps to draw it tight

  to the old joist. Face-nail the two together, stag-

  gering 16d nails every 12 in. If there’s no room to

  New

  swing a hammer, use a pneumatic palm nailer to

  partition

  drive the nails most of the way.

  angled-end joist. Where joists will rest on a

  Existing studs

  foundation mudsill at one end and hang from a

  girder at the other (rather than sitting atop it),

  Finish

  cut away the top corner of the end that will rest

  surface

  on the mudsill so it will fit between the mudsill

  and subfloor. Cut the other end square to butt to

  Where a new partition abuts an existing wall,

  the girder. Place the angle-cut end of the joist on

  cut back finish surfaces to the centers of the

  edge over the mudsill, then lift the squared end

  nearest stud on either side, and add studs

  and slide it toward the girder until it butts

  to nail the partition to.

  against it. Angle-cut joists must be a few inches

  shorter than the original joist you’re sistering to.

  You may need a plumbed adjustable column

  the high spot and gradually tapering out.

  or a screw jack to raise the joist until it’s flush to

  Because knots are hard, they’ll take more passes.

  the underside of the subflooring. Once it is flush,

  Use your straightedge to check your progress,

  use a double-joist hanger to join the new joist

  and use taut strings to check the whole wall

  and its sister to the girder. Face-nail the two

  again after building up or planing down the

  joists, staggering 16d nails every 12 in. Remove

  studs. Caution: Wear eye protection when using a jacks and replace blocking between joists. Should

  power planer.

  the double-joist hanger overlap a hanger already

  Common sense and “feel” are a big part of this there, predrill the metal so that you can nail

  process: If all the studs in the wall have a slight

  through both hangers with case-hardened hanger A palm nailer is ideal in tight spaces

  bow inward or outward, the wall won’t be flat,

  nails. To learn more about jacking safely, see

  where you don’t have room to swing

  but drywall covering it may look flat. In that case, chapter 10.

  a hammer.

  leave the studs as they are.

  Flitch plates. Steel flitch plates are sometimes

  bOlSTering JOiSTS

  used to reinforce undersize beams or joists.

  Because they are typically 3⁄8 in. to 1⁄2 in. thick

  Widespread sagging or excessive springiness in

  and must be predrilled, they’re not well suited to

  a floor is probably caused by joists that are too

  casual installation by nonspecialists. There’s

  small for the span or by post, pad, and founda-

  more on flitch plates on p. 64–65.

  tion failure, as covered in chapter 10. Isolated

  joist failure is usually caused by insect or water

  meTal STudS

  damage, alterations to the joist, or a point load

  from a heavy piece of furniture or bathtub.

  Lightweight steel studs are still relatively rare in

  If there’s infestation or rot, correct that

  home construction, but they are appropriate for

  condition first.

  certain tasks. They’re dead straight—one big

  Structural Carpentry

  201

  surface to—especially 15⁄8-in.-wide studs, which

  won’t take up much room in space-starved base-

  ment remodels.

  Stud

  zzzzzz nailing Off Sole Plates

  Metal stud walls are also a snap to take out

  because they’re assembled with self-tapping

  Sole plate

  sheet-metal screws. That’s why they’re used so

  often on commercial or retail spaces. A green

  delight, they can also be recycled completely.

  leveling ceilings. Metal studs really shine when

  you need to level a ceiling whose slope would be

  especially noticeable against, say, cabinets with

  crown molding. Because metal studs are so light,

  they go up quickly, yet they are sturdy enough to

  support a new drywall ceiling. This procedure is

  called “furring down a ceiling,” and using metal

  studs is much easier than ripping tapered wooden

  SOLE PLATE OVER JOISTS

  strips to create a leveled ceiling, which is hugely

  time-consuming and often doesn’t look very good.

  1. Start by tearing out the existing drywall or

  plaster ceiling to expose the ceiling joists. (If ceil-

  ing joists are undersize or rotted, fix those condi-

  Sole plate

  tions first.)

  2. Using a laser level, establish a level line

  around the room, 1⁄4 in. below the lowest point of

  the ceiling joists.

  3. At this height, drive nails into the corners

  of the room. Stretch string perpendicular to

  the ceiling joists at both ends of the room and

  roughly every 3 ft. or 4 ft. in between.

  Blocking

  4. With the aid of a helper, lift the steel studs

  over the leveled strings, and lower each stud until

  Joist

  its bottom edge is 1⁄16 in. above the strings. (The

  1⁄16-in. gap is necessary to avoid moving the align-

  SOLE PLATE OVER BLOCKING

  ment strings.)

  5. Once each steel stud is correctly positioned,

  use 1-in. screws to attach it to a joist face; space

  When a partition runs parallel to the joists, try

  screws every 16 in. along the length of the stud.

  to position it over a joist so you’l have something

  Place screws back at least 1⁄2 in. from the lower

  to nail the sole plate to. If you can’t reposition

  edge of the joist. Use aviation snips or a metal-

  the wall, add blocking between the joists.

  cutting blade in a reciprocating saw to cut light-

  weight steed studs.

  TreaTing inSeCT inFeSTaTiOnS

  advantage over much of the wood framing that’s

  available today. If you work with them, eye
and

  If you see signs of an infestation, hire a pest-

  hearing protection are a must—as are rubberized control professional to assess and remedy it.

  cloth gloves to protect your hands.

  Pesticides are often toxic, and anyone unfamiliar

  Metal studs are sometimes specified in resi-

  with insect habits may not destroy all their nest-

  dential situations where fire is a concern, say, in

  ing sites or may apply pesticides inappropriately

  common walls between living spaces and a

  or unnecessarily. Moreover, local codes may

  garage. They are also good for framing kitchen

  require a professional.

  lighting soffits or for forming chases, essentially

  It’s often difficult to tell whether an infesta-

  long, shallow boxes in which to run mechanicals

  tion is active. For example, if a subterranean ter-

  such as pipes, ducts, or wiring. As shown on the

  mite infestation is inactive, a prophylactic treat-

  facing page, lightweight steel studs are also ideal

  ment may suffice. But if the infestation is active,

  for furring out a foundation wall to attach a finish the remedy may require eliminating the condi-

  202 Chapter 8

  zzzzzz leveling a Ceiling with Steel Studs

  Joist

  Steel studs

  Steel stud

  Taut string

  Low point

  of joists

  Nail

  Nail

  1/4 in.

  1/16 in.

  Taut string 1/4 in. lower

  than lowest joist

  Lowest joist

  This wall sheathing shows evidence of fungi and insect

  damage. After failed window flashing allowed water

  Level laser line

  Laser

  behind a stucco exterior, wood-destroying fungi grew

  around the room

  quickly. Then subterranean termites tunneled, consuming

  the moist, fungus-damaged wood. Cross-grain checking

  just above center is a typical sign of fungus damage. A

  beetle larva showed up, too.

  Steel studs let you establish a level plane of nailers for eventual drywall.

  tions that led to the infestation (such as excessive

  As detailed in the text, measure up from a level laser line, drive a nail at

  moisture and earth–wood contact) and an

  each room corner, and stretch a string perpendicular to the joists at each

  aggressive chemical treatment. Treatment usually

  end of the room.

  consists of applying a chemical barrier on the

  ground that repels the termites or a “treated

  zone” whose chemical doesn’t repel them initially wings of different sizes. Although they do tunnel

  but later kills or severely disrupts them.

  in wet or rotting wood, they do not eat it as food

  Termites, the most famous of insect pests,

  and are therefore less destructive than termites.

  include drywood, subterranean, and Formosan

  To locate their nests, look for borings rather like

  types. Because subterranean termites need access coarse sawdust. Professionals will often drill into

  to moisture in the soil, they build distinctive dirt

  nests and spray them with an insecticide safe

  tubes up along the surface of foundations. When

  enough for inside use; dusting with boric acid is

  they eat into the wood, they usually proceed with another common treatment.

  the grain. Termites swarm in spring or fall.

  Powder-post beetle holes look like tiny BB-gun

  Discourage the return of subterranean termites

  holes; their borings resemble coarse flour. Because

  by lowering soil levels around foundations, foot-

  these insects favor the sapwood, evidence of bor-

  ings, and the like.

  ings may be only superficial until you prod with

  Drywood termites hollow out chambers sepa-

  a pocketknife. Still, holes are not a sure sign of

  rated by thin tunnels and often travel cross-grain; an active infestation. One approach is to remove

  they eject fecal pellets through holes, with the

  the damaged wood, sweep up borings, paint the

  pellets forming pyramid-shaped piles. Fumigation area, and monitor it for a year. If holes reappear,

  is effective for drywood termites, but it’s ineffec-

  it’s an active infestation: A professional will need

  tive for treating subterranean termites because

  to fumigate the wood or apply a pesticide.

  their colonies are located in the ground and

  fumigation gas does not penetrate the soil.

  dealing wiTH rOT

  Formosan termites, whose colonies may

  If wood is spongy, contains wispy fibers that look

  exceed 1 million individuals, are wreaking havoc

  like cotton, or disintegrates without reference to

  along the Gulf Coast of the United States; they

  the grain, it is infested by a rot fungus. The white

  live in the ground or in buildings and build huge, strands are spores.

  hard nests.

  Carpenter ants are red or black, 1⁄4 in. to 1⁄2 in.

  long. Sometimes confused with termites, these

  ants have narrow waists and, when winged,

  Structural Carpentry

  203

  If the rot is limited to a few spots, suspect

  leakage and look for other clues above. Water

  may be entering from inadequate roof flashing,

  zzzzzz Sistering Joists

  blocked gutters, or—quite common in older

  SISTER JOIST SITS ATOP SILL AND HANGS OFF GIRDER

  houses—windows or doors that lack flashing

  altogether, in which case there will probably be

  Subfloor

  fungus damage to walls and ceilings inside. Also,

  look for structural damage beneath tubs, sinks,

  New joist

  Slide joist

  and water heaters; if you find any, make sure the

  cut 2 in. short;

  to girder.

  angle-cut this end.

  damage hasn’t progressed into subflooring and

  floor framing.

  Rotted wood, unsightly as it is, poses no

  2

  threat to healthy wood nearby, as long as you

  1

  control the moisture that encouraged the fungus

  in the first place. Cut out deteriorated sections,

  3

  but don’t bother to remove discolored wood that

  Attach hanger

  is solid; leave it in place, especially if flooring is

  when joist is

  Girder

  2x6 mudsill

  flush.

  water, insects, rot,

  Double

  joist hanger

  and mold

  whether structural damage is caused by insects or

  To a sister a new joist when one end will rest on a mudsill and the other will hang

  rot fungi, excess water is usually at the heart of the

  from a girde, angle-cut the mudsill end and slide it into place. Then raise the other

  end until it’s flush with the girder before attaching with a hanger.

  problem. before treating the specific agent causing

  the deterioration, reduce excess water by maintaining

  gutters, improving drainage, grading the soil away

  from the building, eliminating wood–soil contact, and

  improving ventilation.
/>   The fungi that rot wood reproduce by airborne

  SISTER JOIST SITS ATOP SILL AND GIRDER

  spores, so they’re virtually everywhere. but they can’t

  establish colonies on wood with a moisture content

  Beveled edge

  Subfloor

  (mC) less than 28%, and they go dormant if the mC

  drops below 20% or the air temperature drops below

  40°F. Household molds, also caused by fungi, thrive

  in a similar moisture and temperature range. So if

  New joist

  moisture-meter readings in your basement or crawl-

  space are too high, reducing excess moisture may

  solve both wood rot and mold problems.

  How you reduce moisture, however, is something

  experts can’t agree on (see 256–259 and chapter 14

  Girder

  or mudsill

  for more on mitigating moisture and mold). many

  building codes recommend covering dirt floors in

  crawlspaces or basements with sheet plastic and

  installing screened vents to circulate air and disperse

  moisture: 1 sq. ft. of vent per 100 sq. ft. of floor space

  Old joist

  is the standard formula. whereas another group of

  builders argues that it makes more sense—especially

  in the humid South—to close vents, insulate crawl-

  To “sister” a new joist to one that sits atop a mudsill

  on one end and a girder on the other, bevel the leading

  space or basement walls, seal air leaks, and install a

  top edge so it will “sledgehammer “ into place.

  dehumidifier. That, they argue, will stop mold from

  colonizing and migrating to living spaces. best bet:

  See which approach builders in your region favor.

  204 Chapter 8

  nailed to it. You can reinforce existing joists by

  sistering on new ones, but before doing so, allow

  Stair liNgo

  the old joists to dry thoroughly.

  The two-part epoxy repair discussed on p. 163,

  As shown below, stringers and carriages support steps. Stringers serve as the diagonal

  though interesting, is primarily a cosmetic fix.

  support frames on each side. And carriages carry by means of a sawtooth pattern cut

  Most epoxy fills are inappropriate for structural

  into them. Stringers and carriages are often fastened together. Another option is a

  elements. Some companies, such as ConServ

  housed stringer, in which a stringer has routed grooves that receive and support tread

  Epoxy, make products specifically for structural

  and riser ends.

  repairs.

  Stair Repairs

  Stairs are complicated to build, and problems

  can be tricky to diagnose. For example, it may

 

‹ Prev