A torn area in a room's drywall facing looks hideous, but it's easy to fix when you know the right procedure. Just filling the area with joint compound will not correct the problem. The visible area of gypsum that lies under the drywall facing needs to be sealed to protect the gypsum and prevent the paper around the torn area from bubbling up when you repair the tear. Using the right method, you can make your wall look like new again.
Score the drywall approximately 1 inch from the tear, all the way around it. Remove the scored paper to create an even, crisp edge around the torn area to prevent any paper nubs from sticking out.
Seal the area -- the paper edges and the exposed gypsum -- with a coat of fast-drying oil-based sealer. Allow the sealer to dry completely before continuing. The sealer creates a protective surface between the exposed gypsum and the new layer of joint compound. It keeps water from penetrating into the gypsum. Other effective sealers include clear or white shellac, oil-based paint or spray sealers.
Load the edge of the 4-inch drywall knife with joint compound. Tilt the drywall knife at a 45-degree angle and place it on one edge of the torn facing. Pull the drywall knife over the torn area and spread the joint compound over the area. Let the compound dry before adding another coat, if needed, and repeat the process until the area is filled. The top of the joint compound should be flush with your wall. If the area still feels lower than the surrounding wall after it's dry, apply another thin layer of drywall compound. Allow it to dry completely.
Check the area to see if it is smooth. Rub your hand over the surface of the dried joint compound. If you feel rough areas, sand it with 220-grit sandpaper until smooth. The area is now ready for paint or another wall covering.