Renovation 4th Edition

by Michael Litchfield

  tape. Sand the first coat of joint compound light-

  to countersink a hole 1⁄8 in. deep for each washer.

  ly, leaving it a little rough so the second coat

  Sunk below the surface of the plaster, the screw

  adheres better. Then apply the second coat, feath-

  heads and washers will be easy to cover with

  ering it out to blend in the patch’s edges.

  patching compound.

  When the patch dries, sand it lightly with fine,

  Place screws and washers every 8 in. to 10 in.

  220-grit sandpaper, wipe it clean, allow it to dry

  on both sides of the crack and anywhere else the

  thoroughly, and prime the patch with an oil-

  plaster seems springy and disconnected from the

  based primer.

  lath. Once you’ve stabilized the crack in this man-

  ner, scrape, tape, and fill it, as described earlier.

  Large cracks often accompany sections of

  bowed or sagging plaster, which have pulled

  Small holes, the size of an electrical outlet, are

  free from the lath. If the plaster is sound—not

  easy to fill if the lath is still in place. Remove any

  crumbling—you can reattach it to the lath using

  zzzzzz patching Cracked plaster

  zzzzzz patching Holes in plaster

  Plaster

  Lath

  Original

  wood lath

  missing

  Plaster

  1/8-in.

  washer

  recess

  Spade bit

  Metal lath

  Wire loop

  replacement

  Pencil

  holding lath

  in place

  If plaster lath has been cut out, replace it

  before patching the hole. Insert and secure

  a smal section of wire lath with a wire looped

  around a pencil, as shown. Twirl the pencil

  Cracked plaster often means that it has

  to draw the wire lath tight to the back of

  pulled free from its lath. Use screws and

  the plaster, then fill the hole with two coats

  plaster washers to reattach it, countersinking

  of patching plaster. Unwind the wire and

  them so they’ll be easier to patch.

  snip it when the first coat is hard.

  Finish Surfaces

  443

  loose plaster, brush out the debris, wet the lath

  and the surrounding plaster well, brush on a PVA

  bonder, and trowel in patching material. Leave

  zzzzzz Casting larger

  Replacement Molding

  the first coat a little rough, let it dry well, and

  apply bonder again before troweling in a second,

  RTV-rubber-and-

  Replacement

  smooth coat.

  cheesecloth mold

  casting

  If the hole has no lath behind it, you’ll need to

  add some. Scrape the loose plaster from the edge

  of the hole. As shown in “Patching Holes in

  Plaster” on p. 443, cut a piece of metal lath larger

  than the hole and loop a short piece of wire

  through the middle of the lath. Then, holding the

  ends of the wire, slide the lath into the hole. To

  pull the lath tight against the back of the hole,

  insert a pencil into the front of the loop and turn

  the pencil like an airplane propeller until the wire

  is taut. The pencil spanning the hole holds the

  lath in place.

  Sand bed to

  After wetting the lath and surrounding plaster,

  support mold

  Box

  spread a rough coat of compound into the hole.

  When the coat has set, unwind the wire, remove

  When a repetitive plaster pattern is

  the pencil, and push the wire into the wall cavity.

  damaged, replace damaged sections with

  The hardened plaster will hold the metal lath in

  castings made from sections that are intact.

  place. Trowel on the finish coat.

  Large holes with lath intact should be partially

  patched with a piece of drywall slightly smaller

  the lath—textured side out. The patching plaster

  than the hole. Because a hole with square cor-

  will ooze through the holes in the pegboard and

  ners is easier to patch than an irregular one,

  harden in the same manner that plaster keys into

  square up the edges of plaster using an oscillat-

  the spaces between lath strips.

  ing multitool or an oscillating multitool with an

  abrasive wheel. (Wear safety glasses.) Be careful

  RESTORiNg plASTERWORK

  not to cut through the lath. Use type W drywall

  Restoring damaged crown molding, medallions,

  screws to attach the drywall to the lath behind,

  or other plaster ceiling ornaments takes patience,

  stretch self-adhering fiberglass mesh tape around hard work, and a lot of skill. You may be better

  the perimeter of the patch, and apply joint com-

  served replacing the originals with plastic or

  pound or patching plaster as described earlier.

  composite reproductions. They are good looking,

  For best results, the drywall should be slightly

  lightweight, easy to install, and—once painted—

  thinner than the existing plaster so you have

  indistinguishable from plaster ornaments. Given

  some room to build up and feather out the patch.

  the hourly rates of a skilled plasterer, this strategy

  As an alternative, pegboard is a dandy sub-

  is usually far more cost-effective.

  strate for these patches because you can cut it

  However, if your plaster ornament has a repet-

  easily with a jigsaw to fit irregular holes. Hold a

  itive pattern with only a few damaged sections,

  sheet of 1⁄4-in. pegboard over the plaster, eyeball

  you can cast replacement sections by creating a

  and trace the shape of the patch through the

  mold from an original, undamaged section.

  holes in the pegboard, and screw the pegboard to Removing an ornamental section. If you want

  to make a casting, you need to remove an undam-

  aged ornamental section. First, support the sec-

  JUST

  tion that you will remove. To do this, position a

  Wiggle yOUR FinGeRS 2x4 tee, its head covered with rubberized floor

  to mix plaster, pour it into water as you wiggle your fingers in the bottom of the pan.

  padding, under the ornament to cushion and

  mixed that way, the plaster will set slowly and will be usable longer. if you pour water

  protect any delicate details. Then use a circular

  into plaster, on the other hand, it will start setting within 5 minutes.

  saw with a Carborundum blade or a recipro-

  plaster is easier to clean up if you mix it in a plastic tub. allow it to dry, then strike

  cating saw with an 18-teeth-per-inch (tpi), bimetal

  or twist the bottom of the tub to make the plaster fall out in chunks.

  demolition blade to cut around the section. The

  section should include a complete pattern repeat

  plus 2 in. on each end to allow for some damage

  444 Chapter 15

  when you remove the piece. This is dusty work

  Before cutting the new casting to length, min-

  and you’re sure to hit nails, so w
ear a respirator

  imize fragmentation by first scoring the cutting

  mask and goggles.

  line with a utility knife and then cutting with a

  Note: There may well be wires or pipes run-

  fine-toothed hacksaw.

  ning through the ceiling, so explore beforehand

  How you attach the replacement piece

  after turning off the electricity to the area. In

  depends on its composition. If your casting is

  many cases, ceiling joists will be exposed in the

  plaster, use Durabond 90 quick-setting com-

  attic above. Plan cuts so they miss wires and

  pound to adhere the plaster ornament to the lath.

  pipes. Replacing the section will be easier if you

  Dampen the replacement piece so it doesn’t leach

  don’t cut through the lath, but that’s sometimes

  moisture from the Durabond, and use the 2x4 tee

  impossible to avoid. After cutting around the sec-

  to support it until the compound sets—about

  tion, you can often slide a chisel behind it and try 90 minutes. For good measure, predrill holes at a

  to break off the plaster keyed into lath spaces.

  slight angle every 10 in. along the edge of the cast-

  ing to receive drywall screws with plaster wash-

  Casting replacement sections. To reproduce

  ers. If your replacement casting is a lightweight

  replacement sections, you must first create a

  polymer, you won’t need screws; a few beads of

  mold. Room temperature vulcanization (RTV)

  construction adhesive or white glue will do the

  silicon rubber, made by combining two compo-

  job. Before setting the replacement piece, dry-fit

  nents, is a good choice for molds: It can duplicate it to make sure it’s the same thickness as the old

  fine details and is available from most arts-and-

  plaster; you may need to build it up slightly. Last,

  crafts stores and online. After you’ve removed an

  fill the cracks or flaws where the new sections

  original section in good condition, use a tooth-

  join old before painting the restored ornaments.

  brush to remove flaking paint, then repair any

  small damage with plaster of paris. Shellac the

  section so its surface will be slick, and let it dry.

  Soundproofing

  To make the mold, paint on a coat of RTV sili-

  Soundproofing is serious science. Done correctly,

  cone rubber, and allow it to dry. Thereafter, alter-

  it’s much more complicated and expensive than

  nate strips of cheesecloth and rubber, allowing

  just adding fiberglass batts between studs or ceil-

  each RTV-and-cloth layer to dry before applying

  ing joists. Fortunately, there are commonsense

  the next coat. Three or four layers should give you solutions that won’t cost all that much and will

  a mold that’s sturdy enough. When the final coat

  go a long way toward mitigating sound. But first,

  is dry, peel the RTV mold off the original plaster

  a little science about how sound travels.

  section, and pour a new casting into the mold.

  Basically, sound travels through the air or

  Although plaster is a suitable casting material, through the structure of a building. Airborne

  it’s heavy. If the original object is large—for

  sounds travel in radiating waves through open-

  example, a ceiling medallion—consider casting

  ings of any size. Those sound waves continue

  with a lightweight polymer such as polyurethane

  until their energy is absorbed—and the more soft

  or polystyrene, which won’t shrink, paints well,

  or porous materials they encounter, the sooner

  and is available in different densities. Or you may that energy is spent. Structure-borne sounds are

  need to support the mold in a bed of sand so the

  transmitted through contact between solid mate-

  new casting material doesn’t distort the mold.

  rials, and those solids can be as small as a copper

  For larger casts, fill a large enough box with

  supply pipe in contact with a wall plate or a dry-

  sand, and—before peeling the mold from the

  wall screw sunk in a ceiling joist. To stop struc-

  original plaster section—press the mold into the

  tural sounds, you need to isolate them, say, by

  sand. Then lift out the mold, and peel the rubber

  putting a piece of foam or heavy vinyl between a

  carefully from the original plaster. Return the

  vibrating appliance and the floor it sits on.

  empty mold into the impression it made in the

  Point being, because noise—the sounds we

  sand. Pour the new plaster (or polymer), and

  don’t want to hear—can travel through tiny open-

  level it off to the top of the mold. When the cast-

  ings or be transmitted through structural ele-

  ing is completely dry, lift it and the mold out of

  ments as small as a screw, successful soundproof-

  the box, and peel off the mold.

  ing is all about paying attention to details. How

  installing new castings. Once you have cast

  many details you can attend to will depend on

  replacement sections, measure both the damaged the extent of your renovation. If you’re gutting

  and replacement sections carefully so the repeti-

  the interior, you can do a lot. But even a room

  tive pattern will match exactly when you install

  left intact can be improved.

  them. Then cut out the damaged ceiling sections,

  leaving the lath intact and being careful to cut

  the ends as cleanly and squarely as possible.

  Finish Surfaces

  445

  THREE SiMplE SOlUTiONS

  glass insulation. ABS or PVC waste pipes are

  inherently noisy, however, so if you want to

  It’s finally happened: You’re somebody’s parent

  silence flushing noises in waste pipes forever, bite

  and you’re telling your kid to TURN IT DOWN!

  the bullet and install cast-iron DWV pipes. Less

  So next birthday or holiday, get that sonic-busting expensive is making sure that DWV pipes are

  offspring or your hard-of-hearing mother a pair

  well secured with pipe straps, hangers, and

  of really nice headphones, ones so nice and cushy clamps (see the top right photo on p. 333) and

  that he or she will want to wear them. You will be supply pipes are immobilized by Acousto-Plumb

  spared exploding aliens or the evening news at

  clamps (see the top photo on p. 345) and other

  60 decibels (db.), and peace will reign. Second,

  plastic pipe-support flanges.

  if footfalls in a room overhead have you edgy, a

  Electrical cables and devices are pretty quiet

  carpet with a substantial pad can be a better

  as mechanical systems go, but their routing holes

  sound suppressor than installing insulation

  and cutouts for outlet boxes will transmit air-

  between floor joists. Third, heavy curtains, over-

  borne sounds—especially when outlet boxes are

  stuffed furniture, and rugs will all absorb sound,

  back to back in a shared wall. Fill holes in fram-

  whereas hard, reflective surfaces such as tile or
<
br />   ing with expanding foam, caulk around outlet

  laminate counters can make living spaces sound

  boxes, and, if you want to do an A1 job of stop-

  as homey as a hospital corridor.

  ping air leaks and hence sounds, wrap outlet

  Appliance science. Any appliance with a motor

  boxes in dense vinyl jackets. However, do not

  will vibrate and create noise. Washers, dryers,

  wrap recessed ceiling cans. IC-rated light fixtures

  and refrigerators are the biggest offenders

  (see pp. 393–394) can be covered with loose

  because they have the biggest motors. Your appli- insulation or insulation batts (but not vinyl

  ances aren’t noisy? Put your ear to the floor when jackets). However, non-IC-rated fixtures must

  they’re running. To mitigate appliance noises in

  not be covered with insulation—or anything else

  P R O T I P

  an upstairs in-law unit, master carpenter Alan

  that would cause these fixtures to overheat and

  Jencks of Berkeley, Calif., installed the type of

  cause a house fire.

  When using resilient channel

  thin foam pad typically used under floating

  for soundproofing, use screws of

  floors, covered that with 1⁄4-in. plywood under-

  SOUNDpROOFiNg BETWEEN FlOORS

  two different lengths. The longer

  screw, typically 11⁄4 in., will

  layment, and then installed resilient flooring atop Correctly soundproofing between floors may

  attach the channel to the fram-

  that in the apartment’s kitchen and laundry

  require gutting finished ceilings and exposing

  ing. The shorter screw, say, 1 in.,

  room. But Jencks wasn’t done. He mounted the

  joists. The soundproofed ceiling on the facing

  will attach the drywall to the

  washer and dryer on a plywood platform fas-

  page shows one approach, which requires access

  channel— but not to the framing.

  tened to the steel-and-neoprene vibration isola-

  from above and below to create a “sandwich”

  in other words, if the screws

  tors often used to mount commercial cooling

  of doubled 5⁄8-in. drywall panels filled with

  attaching the drywall reach the

  units to roofs. Granted, his solution took a few

  R-19 fiberglass batts. Two noteworthy details:

  framing, they will transmit sound

  Google searches, but it solved the problem with-

  The doubled drywall on the ceiling is not screwed

  through the structure.

  out tearing up the floorboards.

  to joists but to resilient channels, which allow