How to Fix Moldy Drywall

Fixing moldy drywall should be a priority.

Once you find mold in your home, it is important to remove it as soon as possible. While mold should be removed for health reasons, it should also be removed to mitigate the damage to your home. Mold grows in moist areas and moisture is damaging to many building materials. If mold has damaged drywall, it should be replaced and not just cleaned. And because mold is a sign of moisture, it is important to find and fix the source of the moisture before completing the project.

Things You'll Need

• Drywall saw
• Box cutter or razor knife
• Antimicrobial spray or bleach and water solution
• Putty knife
• Drywall screws (1 1/2-inch)
• Drywall joint compound
• Drywall finishing knife
• 150-grit sandpaper
• Paint and paintbrush

Instructions

1. Cut out moldy drywall with a drywall saw or razor knife, removing all drywall that contains any moisture. This will help prevent mold spores from spreading.

2. Mist the mold lightly with a bleach and water mixture or antimicrobial spray. This prevents mold spores from becoming airborne.

3. Remove all mold inside the wall cavity by scraping with a putty knife and wiping clean with a rag and antimicrobial solution. Allow the wall cavity time to completely dry, then re-spray with your antimicrobial solution.

4. Measure the area in which the moldy drywall was removed and cut a new piece of drywall to fit.

5. Fasten your drywall patch to the wall studs with drywall screws. Use coarse-thread screws for wood studs or fine-thread screws for metal framing. Normally, a 1 1/2-inch drywall screw works best.

6. Apply a thin layer of drywall joint compound with a 4-inch drywall finishing knife on all of the joints and apply drywall tape.

7. Embed the drywall tape into the joint compound along all joints, using a drywall finishing knife.

8. Apply a cover coat of joint compound on all tape joints. This puts a second coat on top of the drywall tape, concealing the joint. Allow the joint compound to dry.

9. Sand with 150-grit sandpaper.

10. Repaint surfaces as necessary with a paintbrush, using a paint with a fungicide additive to minimize the risk of further mold problems.

Tips & Warnings

• Depending upon the size and location of the repair, it may be best to cut it back to expose 1/2 of a stud to the left and right for purposes of securing the drywall patch.

• Always wear a breathing mask and wear disposable gloves when handling mold.

• The health effects of living with mold are in debate, but it is agreed that mold, at the very least, can be an irritant.

References

• InspectAPedia: Mold on Walls, Drywall, or "Sheetrock"--How to Find & Test for Mold on Walls