How Do You Know If Mold Is Behind Drywall?

Stacy CookMold Issues

How to Spot and Address Mold Behind Drywall

Mold can cause serious problems in any home, including health issues. Because it thrives in moist environments, mold often hides behind walls for long periods without detection. Drywall, a common building material, makes spotting hidden mold even more difficult. If you suspect mold behind your drywall, watch for the following warning signs.


Signs of Mold Behind Drywall

1. Visible Mold on Walls

Mold loves damp, warm environments. The most obvious sign is visible mold on the wall’s surface. It can appear in different colors and textures, sometimes fuzzy or slimy. If you see mold on the surface, there’s a strong chance it’s also growing behind the drywall.

2. Persistent Moisture Problems

Water stains or frequent condensation point to a moisture problem inside your walls. Stains mean water is seeping into the wall cavity—an ideal breeding ground for mold. Solve the moisture issue first to stop further growth.

3. Musty or Unpleasant Odors

Mold produces a distinctive musty, earthy smell. If you notice this odor indoors, especially in one area, mold could be hiding behind the drywall.

4. High Indoor Humidity

Consistently high humidity creates perfect mold-growing conditions. If your home feels damp or humid, mold could be forming where you can’t see it.

5. Wall Discoloration or Surface Damage

Peeling paint, bubbling wallpaper, or unusual stains can indicate water damage and possible mold growth behind the surface.

6. Allergy Symptoms Indoors

If you or someone in your home has sneezing, itchy eyes, runny nose, or coughing that worsens indoors, mold might be the culprit.

7. Warped or Bowing Walls

Water damage can warp or bow drywall, often signaling mold activity behind the wall.


How to Detect Mold Behind Drywall

Visual Inspection

Look for visible signs of mold, water stains, or damage, especially near sinks, showers, and other moisture sources.

Use a Moisture Meter

A moisture meter measures water content in building materials. High readings may indicate hidden mold.

Air Sampling

Air tests can detect mold spores in the environment, pointing to hidden growth inside walls.

Infrared Imaging

Infrared cameras reveal temperature differences that indicate hidden moisture.

Removing the Drywall

Cutting into the drywall provides the most conclusive answer. If mold is present, bring in a professional for safe removal and cleanup.


Mold Remediation Steps

1. Eliminate the Moisture Source

Stop leaks, improve ventilation, and reduce humidity before tackling the mold itself.

2. Remove Contaminated Materials

Discard moldy drywall or other affected materials to stop the spread.

3. Clean and Disinfect Remaining Surfaces

Scrub and disinfect all exposed areas to remove lingering spores.

4. Restore the Area

Replace drywall, repaint, and ensure the space is well-ventilated to prevent mold from returning.


Final Thoughts

Mold behind drywall can stay hidden for a long time, but the warning signs are often there if you know what to look for. Detect it early using inspection and moisture detection tools, then bring in professionals for proper remediation. Acting quickly protects both your health and your home’s structure.