By Mike MorrisMore in Windows Walls and Doors
Unlike plaster, drywall has a seamless paper covering that rarely cracks or splits. When a crack appears, it is usually on a seam where two drywall sheets meet, and it is easily fixed.
If the crack is on a vertical or horizontal seam, carefully widen the crack with the corner of a paint scraper, utility knife or chisel to determine if the crack extends completely through the paper that is covering the seam (image 2); and if the tape has pulled loose from the wall surface. If the tape is intact and well-adhered, the crack was probably caused by the old drywall compound drying and shrinking. Simply fill the crack with new compound. When applying the compound, hold the knife at a 70-degree angle and swipe across the crack. Make sure the knife is clean by scraping both sides of it over the edge of the pan. Allow the joint compound to dry completely then lightly sand the area (image 3). Wipe away the dust then paint over it.
If the crack extends through the seam’s paper tape, or if the tape has pulled loose from the wall, use a razor knife to cut the tape about 6 to 12 inches from both ends of the damage (image 1 and 2). Remove the tape but be careful not to tear away the drywall’s paper covering. Scrape away any loose compound, and use a razor knife or drywall saw to expand the crack through the wall surface into the stud cavity (image 3). Avoid removing solid, well-adhered compound beyond the crack itself.
Fill the crack with new drywall compound, and apply a thin coat of compound to the wall surface where the old tape was removed. While the compound is still wet, place a strip of fiberglass tape over the seam, bridging the gap between the ends of the existing tape (image 4). Use a putty knife to gently flatten wrinkles and to bed the tape into the compound.
After the compound dries, add a second thin coat of compound over the taped area. Cover the tape and taper or “feather” the edges of the new compound onto the surrounding wall surface (image 5). Drywall compound needs to be applied in multiple thin layers because thicker layers are too difficult to smooth out and will eventually cause cracking.
When the second coat is thoroughly dry, sand lightly to smooth out any bumps. Next, use a wide (8- to 12-inch) joint-compound taping knife to completely cover the patch with a third and final coat. Try to blend this coat as seamlessly as possible onto the wall surface. After it dries, sand lightly, wipe away dust and repaint the entire area.
A common drywall problem, especially in newer homes, is “nail pops,” or nail heads that pull away from the wood studs and protrude through the drywall tape or paint. This is usually caused by warped wood that was inadequately dry when installed. Although the drywall is rarely in danger of falling off the wall, the bumps are visible and unsightly.
Use a utility knife to scrap away the drywall until the screw is exposed.
Then there are two ways to fix nail pops: use a screwdriver or hammer to drive the nail back into the studs (image 1), then bracket each nail head with closely spaced drywall screws (image 2); or, remove the nail and drive a screw in its place, along with a second screw nearby, to re-secure the drywall to the stud.
When using drywall screws, be sure to recess the heads slightly, creating a dimple in the drywall surface that can be covered with joint compound, but be careful not to tear through the paper surface. Where several screws are placed in a row, spot-patch each with compound and cover them with a strip of fiberglass tape as described in the stpes above (image 3).