Wallboard has a paper surface that tears easily. Although this will not affect the wallboard's integrity, it does look bad. The repair process is simple, but it can take a while because the torn paper might cause blisters to appear. A coat of oil-based primer over the torn area will remedy this by causing the paper shreds to adhere to the wallboard. After that, you must carefully examine the repair area after each coat of joint compound to make sure no more blisters develop.
Instructions
1. Use a utility knife to score the wallboard around the torn area. Pull away the paper very gently. Try not to remove more paper than necessary.
2. Paint the area with an oil-based primer. The exact type or brand is not important. For small repairs, use a brush to apply the primer. Use a roller for large areas.
3. Cover any deep cracks you see in the wallboard with a coat of ready-mixed joint compound. Then apply a piece of fiberglass-mesh drywall tape over the cracks. Use a 6-inch drywall knife to wipe the tape until it is smooth.
4. Use a drywall knife to apply a thick coat of joint compound over the torn area. For small repairs, a 6-inch drywall knife should be sufficient. For large repairs (over 3 square feet), use a 12-inch drywall knife. Allow the area to dry. When the joint compound turns bone-white, it is dry.
5. Hold a bright light up to the repair area. Look for blisters. If you see any, score around them with a utility knife and pry them away. Use a 6-inch drywall knife to fill the holes. Allow the joint compound to dry fully.
6. Sand the joint compound with 100-grit sandpaper until all lines and tool marks are gone.
7. Add a little water to the joint compound to make it a lighter consistency. Aim for a consistency that is a little thicker than yogurt.
8. Use a 12-inch drywall knife to apply another coat over the area. Try to make the coat smooth. The fewer lines and tool marks you leave, the easier the sanding process will be later.
9. Examine the repair area for blisters again. Use a bright light. Cut out any blisters you find as you did before, and fill the holes with joint compound. Allow your work to dry.
10. Use 150-grit sandpaper to give the repair area a smooth finish.
