Walls and Ceilings

The thing to remember about walls is that something always lies behind them. Not just another room, but the entire infrastructure of your home: water pipes, drainpipes, live wires, gas lines, phone lines, and cable for the television or computer—to name a few items. So before you start messing with walls, know what's behind them. Three tools will help: A stud finder beeps every time you pass it over one of the studs that make up the inside of the wall. A no-contact voltage detector lights up when you pass it over an electrical line. Both are musts if you’re going to do so much as drive a nail.

The third tool is common sense. You know, for instance, that if there is a toilet upstairs, a drainpipe runs from it and a supply pipe runs to it. Plumbers like to run both of them straight up and down: If you're working on a wall below and behind the toilet, be surprised if you don't find them. Lines for faucets, bathtubs, and sinks probably run down through the wall behind them too, though in some cases they'll run through the floor for a short distance in order to reach the wall.

If a gas line runs to a stove or heater, trace its route back to the gas meter. The line most likely runs into the wall and then straight down, or through the floor and straight down. Once the line reaches the basement or crawlspace, it runs horizontally to the meter. If you have a hot-air register in the wall, you also have a heating duct there. Most of the horizontal travel occurs where the vents come out of the heater. From there the vents run inside the walls with as little branching as possible. The same is true of pipes for hot-water heat.

Be prepared to check and double-check thoroughly for electrical lines with the no-contact voltage detector. Turn off the water and power if there is a faucet, tub, toilet, electrical outlet, or switch anywhere in the vicinity. Look for phone lines, cable TV lines, and anything else you can imagine. If you’re doing major work on the wall, carefully remove part of it to get an idea of what's going on behind it. And if you're removing a wall, plan ahead. You need all the wires and pipes it conceals, and each will need a new home once the old wall is gone.

Wall and ceiling basics

In the vast majority of homes built since World War II, interior walls and ceilings are wood frame finished with drywall. The drywall is nailed or screwed to the studs, and the seams are covered with reinforcing tape and filled with plaster like joint compound. Repair is usually a matter of troweling on more compound, though repairing a hole may mean piecing a drywall patch into the wall.

In older houses, thin, closely spaced wood lath strips are nailed to the studs, then plaster is troweled over the lath. These walls tend to be thicker and may be more brittle because of age. Repair cracks with surfacing compound (which, unlike joint compound, is formulated specifically for plaster). Repairing holes usually involves removing the damaged plaster and troweling on a repair compound.

Paneled walls, wood wainscoting, and tile usually can be applied over existing drywall or plaster without repairing the existing wall. Suspended ceilings can cover up damaged plaster or basement joists. A new surface changes the look of the room, though, and is seldom less work than repairing the original. This doesn’t mean you shouldn’t panel the study. It just means that at the start of the job, you need to decide whether you’re repairing or remodeling. Once you know, choose the wall or ceiling treatment that meets your needs.

Product names vary from region to region, company to company, and even contractor to contractor. If you're unsure what something is called, take a sample or picture to the store when you go shopping.

USING PLYWOOD PANELING IS ONE OF THE QUICKEST WAYS TO COVER A WALL. Wainscoting is a tongue-and-groove solid-wood paneling that you piece together on the wall. You need to install it on a solid, flat surface. Installing drywall is a matter of screwing it in place. In bathrooms, use moisture-resistant "greenboard." Fill in seams between pieces of drywall with reinforcing tape and plaster like joint compound, and protect the corners with corner bead. (Use plastic corner bead in basements to prevent rust stains.) Applying tape and compound takes more patience, and often more time, than putting up the drywall itself. Ceramic tile is an extremely durable wall surface. Install it over cement backerboard, which comes in sheets. The mortar designed for use with backerboard comes ready to mix and is called thin set. Once the tile is in place, wipe grout over the surface to fill the gaps between the tiles.

Repairing drywall

MATERIALS: 1x3 scrap lumber or 3/4 inch plywood, 3-inch drywall screws, drywall scrap, self-adhesive fiberglass drywall tape, lightweight drywall compound, fine-grit sandpaper

TOOLS: Framing square, drywall saw, utility knife, electric drill with clutch and phillips-head bit or drywall screw gun, 9-inch and 12-inch putty knives

WALKAWAY - You'll get the best results from any drywall repair job by allowing the coats of joint compound to dry thoroughly before you proceed. Put up the mud and leave it for at least 24 hours. For a smoother finish, use water to thin the final coat of compound to the consistency of mayonnaise.

Traditional plastering was a messy, high-skilled job that required the house to dry out for weeks before painting. Then along came drywall, a thin manufactured sheet of gypsum sandwiched between two layers of paper. Although drywall sheets are notoriously vulnerable to breakage and crumbling, once you nail or screw them fast to studs and joists, they are largely out of harm’s way. However the chalky material will get dinged with exposure. Fill small dents with lightweight drywall compound, then sand before repainting. Repairing larger problem areas involves cutting and fitting a drywall patch.

Fixing nail pops - Nails pop out as the stud holding them dries out, revealing the head of the nail or appearing as if a small disk has been slipped under the drywall paper. If you can remove the nail without damage, do it. Drive a drywall screw an inch or so above and below the pop to secure the wall. If the nail won't come out, drive it back in place, finishing with a slight dent in the drywall that doesn’t tear the surface. Fill the dents or screw holes with joint compound. When dry, sand the patch, then prime and paint.

Lightweight surfacing compound is used for shallow dents and nail holes. It is easily sanded and dries in 15 to 30 minutes.

Spackling paste is for filling larger holes and dents and must be built up in layers \ inch thick. It dries in 10 to 40 minutes and can be sanded.

Wallboard joint compound is strictly for covering taped wallboard joints. It must be applied in thicknesses no greater than 1/4 inch. It comes in containers as large as 5 gallons and is easily sanded.

Paintable latex caulk is the only filler that can handle unstable gaps and cracks on surfaces. Caulk cannot be sanded, so smooth it immediately after application.

1 OUTLINE THE DAMAGED AREA WITH A CARPENTER’S SQUARE. The top and bottom of the rectangle should be an inch or so outside the damaged area. The sides should be centered over the studs on both sides of the hole. For small, persistent cracks try paintable latex caulk. Apply it and smooth with a wet finger.

2 CUT OUT THE SIDES. When the saw blade runs into the studs, make a mark and measure over the stud inch. This is the center of the stud, and the edge of the patch should be directly over it so both the existing drywall and the patch will have support. Cut along the line with a utility knife using several cuts, each one slightly deeper than the previous one.

3 CUT THE SUPPORTS, THEN THE PATCH. Cut 1x3 or 3/4-inch plywood scraps 2 to 4 inches larger than the patch is high. Screw these supports vertically behind the opening to keep the patch from cracking. Hold the support in place and secure it with drywall screws. Avoid driving the screws through the drywall. Cut the patch to size. Measure the opening and use the framing square to lay out the measurements on a scrap of drywall and cut out with a utility knife.

4 INSTALL THE PATCH WITH 1 1/4-INCH DRYWALL SCREWS. Position the screws as far as possible from the edges to avoid splitting or crumbling the drywall. Run strips of self-adhesive fiberglass drywall tape around the installed patch, centering the tape on the seam. Then use a 9-inch putty knife to spread drywall joint compound across the patch and tape to create a smooth, flat surface. Let the compound dry overnight, sand, and apply a second coat. For the smoothest patch, sand the surface to smooth out any irregularities; then spread a third coat with a 12-inch putty knife.

Drywall Crack Repair

1 WHEN YOU REPAIR DRYWALL, YOU HAVE TO MAKE THE SITUATION WORSE IN ORDER TO MAKE IT BETTER. To fill a narrow drywall crack, widen it slightly. Brush off any loose pieces.



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