Water – How much drywall should I remove around a moldy area

basementdrywallmoldwaterproofing

The previous owner told me that during the last winter when snow melted, water got in the basement through the drywall and he had to wipe dry the floor. Last year we had one of the worst winters on record (New York City).

I have a closet where a piece of the drywall (2×3 ft) has some black spots on it and water marks, but the rest of the drywall seems fine. The basement has regular drywall (not the blue one).

The basement doesn't smell musty or bad at all and I have not seen water coming in since then. I am planning on pouring concrete on the outside to take care of water that might be seeping through to the foundation.

If I just remove that small piece of drywall that has some black spots (mold?) on it, should I continue ripping off the rest of the drywall to look underneath? It would mean I would have to destroy the walls etc. what is the best route especially since the basement doesn't smell and I haven't had any issues since and the rest of the walls seem fine.

When I replace the drywall should I spray some stuff inside to kill the mold?

Best Answer

The industry standards, the ANSI/IICRC S520 Standard of Care for professional mold remediation, generally stipulates removal of 24" around the visibly moldy area. We would also generally remove any other wet drywall. If you see visible mold on the room facing side of the drywall, the likelihood of the problem being worse inside the walls is high.