Installing drywall yourself can be a good DIY project for a number of reasons. Drywall installers are often in short supply. And if you do get a good installer to come to your house, the cost of labor may shock you. Drywall work is a job that you can do yourself. But keep in mind some mistakes that do-it-yourselfers often make.
Drywall Is Not on a Stud
All edges of all sheets of drywall must land on a solid surface such as a stud. A hanging drywall edge may work in the short-term, but in the long-term it can result in cracks and other serious wall issues. Sometimes, the drywall does not horizontally reach a stud. Less often, drywall does not vertically reach a solid attachment point.
When drywall extends a few inches beyond a stud, it should be cut vertically so that it hits the center point of the stud.
If the drywall is an inch too short to reach a stud, a second stud can be sistered (or nailed alongside) the first stud to provide an attachment point for the drywall.
If the drywall does not vertically reach a solid section, a short piece of two-by-four can be cut to the width of the stud bay. It can then be nailed horizontally on each side to fit within the bay.
Drywall Paper Is Over-Sanded
In the effort to achieve a smooth surface, many do-it-yourself drywallers vigorously sand the dried mud compound and joints.
But when you sand too far, you risk the chance of sanding into the paper or fiberglass tape covering the seams, or even into the surface of the surrounding drywall, compromising the integrity of the installation. Many homeowners end up retaping seams because they've been too aggressive in their sanding.
Check the sanding progress by installing a light at a low angle to the wall. This will highlight any rises or bumps.
Drywall Screws Are Driven Too Far
The screws or nails are driven too deep so that they break the surface of the paper face of the wallboard. This is a bigger problem than you think because once the paper face is broken, much of the holding power of the screw or nail is lost.
Drive the screw head exactly to the surface of the paper cover. Give it just a quarter-turn or half-turn extra to push it just a bit below the surface.
Special drill attachments are available, and these regulate the depth of the screw. If you're using a screwgun, the tool has a clutch that allows you to set the depth of the drive. If you do puncture the paper, don't bother with removing it; just drive another screw near the failed one.
Misaligned Holes for Electrical Boxes
It's exceedingly difficult to cut a hole in a sheet of drywall and expect for it to perfectly line up with an electrical receptacle that has already been nailed onto the stud. Professionals are good at making the correct measurements; they do this every day. What about for the do-it-yourselfer?
There are many ways around this, but here are three. One easy solution is to apply lipstick on the edge of the receptacle, pressing the sheet of drywall against it, and cutting along the lipstick impression. This is not the best solution, but it will work if you have no other options available.
A second way is to run the electrical cables first and twist the ends together, but don't install the receptacle yet. Mark the location of the receptacle with a square of painter's tape on the floor. Then, install the drywall. Only after it has been installed do you cut a hole. Doing it this way requires that you use retrofit (old work) electrical boxes, rather than the kind that attaches directly to studs.
The third method is best, but it does involve purchasing a special tool called a Blindmark. A magnetic insert goes into the receptacle, and then drywall is installed. With another magnetic piece—which happens to be the same size as a receptacle face—you locate the insert. Draw an outline around the second magnetic piece with a pencil and cut around the outline. Perfect holes usually result.
Drywall Joints Are Too Tight
Close drywall joints are desirable, but not too close as to cause problems.
If you have two adjoining sheets of drywall that fit snugly side-by-side, you risk breaking off the drywall in ways that you didn't imagine. Not only that, but you have to allow for the expansion and contraction of the underlying framing members. Natural seasonal expansion of the wood framing can crack drywall joints that are too tight.
Unfortunately, there is no retroactive fix. However, during installation, be diligent about keeping that 1/8 inch space between sheets by using a guide. The blade of a drywall square is about 1/8-inch-thick and does the trick. Thin strips of wood can also be used as spacing guides.
Failed Drywall Joints
Ideally, all joints between drywall panels would fall over framing members, where both edges can be screwed down securely—top, bottom, and on both sides. This isn't always possible, though, and in situations where a seam between panels falls over the air—known as a hanging joint—failure of the joint is likely.
The temptation is to just lay down the tape and mud it over and hope for the best. But this ad hoc fix rarely works. In a matter of months, such joints will fail and create visible cracks.
Avoid hanging joints wherever you can. Also, the longer the hanging joint, is, the more likely it is to fail.
So for situations such as very tall walls, cover the wall with long panels installed horizontally, so that the hanging joints are supported by studs every 16 inches. Any hanging joint more than 16 inches in span is likely to fail though, so another alternative is to nail in an extra stud or sleeper blocking to provide a surface to nail the joint.