Can Mold Grow Behind Drywall?

Why this question keeps coming up

Finished basements are sold as living space, so people do not want to hear that the wall is a sandwich of wet paper.

What it looks like in York County

East York and Spring Garden have a lot of these finishes. Downtown cellars are less often drywalled and more often simply damp stone. The hidden-paper problem is a finished-basement problem.

What to do

• Meter the wall.
• Open a small area if the smell and the meter agree.
• Remove wet insulation you find.
• Leave masonry exposed until it is dry.

What makes it worse

• Install new drywall over the old stained board.
• Screw cement board over a wet stud and call it resistant.
• Rely on an air sample to map which bay is wet.

Guide: behind drywall.

Questions people also ask

These pages are homeowner education from Radon Mitigation of York, written by Dave Kessler. They are not a medical diagnosis, a species identification, or an insurance determination. Color does not tell you which mold you have. If someone in the house is sick, talk to a physician. EPA's homeowner guidance treats roughly 10 square feet as the line where many people stop DIY cleanup and call a remediation crew — sooner if sewage, HVAC, or anyone immunocompromised is involved. We are a radon and basement crew. When we are already under a York house we will tell you what we see and what we would do in our own place. We do not pretend a radon fan is a mold remedy.