ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Sunday, March 17, 1996 TAG: 9603190002
SECTION: HOMES PAGE: D-1 EDITION: METRO
COLUMN: Hints for Homeowners
SOURCE: STEVE ELDER
Drywall finishing and repair is something that any reasonably handy homeowner can do adequately. The professionals usually can do it faster and better because of their experience and knowledge of tools and materials, but arranging for and scheduling a small repair can take more time than the job itself. Here are a few tips that may enable you to tackle the job yourself:
It always makes things easier to have the proper equipment on hand. Ideally you should have three joint knives in widths of 4, 6 and 10 inches; a tray to hold the joint compound; a screwgun; drywall screws; a keyhole saw; and a utility knife. If you don't have a screwgun, you can make do on small repair jobs by chucking a Phillips bit into an electric drill. Materials needed are usually joint compound, drywall, joint tape and some lumber scraps.
Most residential construction uses half-inch drywall, which normally comes in sizes of 4 feet by 8 feet or 4 feet by12 feet. A 4-by-8 sheet costs under $5.
Basically there are two kinds of joint compound, one which hardens chemically - purchased normally in powder form - and one which hardens by evaporation, the so-called ``ready-mix.'' For finish work, novices should steer clear of the powdered kind. Getting the right mix proportions can be tricky, and it requires more experience to work. Most importantly, it cannot be sanded. Its best application is for deep gouges or holes and large gaps between poorly fitted drywall panels. The pro's also use it when a repair has to be done under a short deadline.
The most commonly available dry mix is Durabond 90, which will set in under 90 minutes. For those who need a faster setting time, Durabond also makes a 45-minute and a 20-minute version. Ready-mix comes in one-gallon and five-gallon buckets, and I recommend the lightweight version for repair jobs because it dries faster. (Tip: Even though ready-mix can be used right out of the bucket, the pro's always add a little water and stir. It makes the compound spread more easily and smoothly.)
To fix a hole, prepare the damaged area by taking a keyhole saw and cutting out a square or rectangular section of drywall around the damaged area. If the damage is over a foot across, cut the damaged area out from wall stud to wall stud. Then take a couple of scrap pieces of 2 x 4 and screw them to the wall stud to provide backing for the new piece of drywall you are going to cut to fit your opening.
I always recommend using screws on any repair work because there is less risk of additional damage caused by the vibration of hammering or by missing with the hammer. If the damaged area is smaller, just square it off. Then take a piece of 3/4 inch wood scrap that is 4 to 6 inches longer than the hole, loop a piece of twine or wire around it to hold it firmly against the backside of the hole, slide it in so that both ends are behind the drywall and screw through the drywall to secure both ends. You can now screw your repair piece onto this backing.
Another method is to cut out the damaged area by holding the keyhole saw at a 45-degree angle. Then cut a drywall plug with the same bevel as your opening and bed it in with joint compound.
Now take a 4-inch joint knife and butter one seam of your repair with enough joint compound to provide a bedding of about 1/8 inch for the tape. Press the tape into the joint compound with enough pressure to squeeze the excess from the sides. Then skim-coat the top of the tape with some more compound. Do this with the remaining three sides and let it dry.
To master this art takes some practice: too little compound will make the tape blister and too much will make it lumpy. After the tape coat has dried, take your 6-inch knife and knock off any ridges or high points you may have left. Then skim the taped seams with another coat.
In applying joint compound, neatness counts. Your tools must be clean, and any joint compound remaining in your tray from the previous application should be thrown away, not put back in the bucket. Otherwise, a hardened bit of compound could get into the fresh mix and plow a furrow in your work. Warning: If you've gotten this coat almost perfect, stop messing with it! After it dries, put the final coat on with the 10-inch knife to feather the final coat out evenly. If joint compound is properly applied it should need very little sanding before painting.
A good professional can apply joint compound so smoothly that hardly any sanding is necessary. (Tip: If your repair area is small, you can sand it with a heavy, flat, slightly damp sponge and raise almost no dust.)
The other common drywall repair is for cracks. To fix cracks, proceed just as described above for the seam between two pieces of drywall. Important: the crack must be taped. It will reappear if it is spackled without being taped.
Cracks in a plaster wall can be repaired in like manner. Holes in plaster on gypsum board can also be repaired like holes in drywall; but repair of plaster laid on wood lath frequently requires different techniques. It is a subject for another day.
Steve Elder is a Roanoke home inspector. Questions and comments may be sent to him in care of The Roanoke Times, P.O. Box 2491, Roanoke, Va. 24010-2491.
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