Why Mold Grows Behind Drywall

Mold needs moisture, a food source, and time. Drywall provides the food in the form of paper backing and organic compounds in the gypsum core. Moisture comes from roof leaks, plumbing failures, or condensation inside walls. Portland's wet climate makes the problem worse. Once moisture gets trapped inside a wall cavity, it stays there because there's no ventilation. The drywall stays damp long enough for mold to colonize, and by the time you smell it, the infestation may cover several square feet of hidden surface.

Signs of Hidden Mold

Look for musty odors that worsen in certain rooms, discolored or warped drywall, peeling paint, or water stains on ceilings and walls. If you've had a roof leak or plumbing issue in the past six months, assume mold is growing in any wall that got wet. Mold does not need visible water to grow. High humidity and dampness inside a wall cavity are enough. Thermal imaging cameras can detect temperature differences that indicate moisture, and moisture meters can confirm elevated levels inside walls without cutting them open.

Professional Hidden Mold Remediation

We start by locating moisture sources using thermal cameras and moisture meters. Then we open walls in affected areas, remove contaminated drywall, and bag it for disposal. If insulation is wet or moldy, it comes out too. We HEPA-vacuum all framing to remove loose spores, then treat structural wood with antimicrobial solutions. Air scrubbers run continuously to capture airborne spores during the process. Once the cavity is clean and dry, we verify moisture levels are below 15 percent before closing the wall. New drywall only goes in after we confirm the space is mold-free and dry.

Insurance Coverage for Hidden Mold

Mold is covered if it resulted from a sudden covered event like a burst pipe or roof leak. Mold from long-term humidity or maintenance neglect is usually excluded. We document the timeline, photograph hidden damage, and provide a detailed scope that explains how the mold developed. If your policy includes mold coverage, we handle the claim and ensure you get the remediation and restoration you need.

If your home smells like mold and you can't find the source, call for a free inspection. We'll locate hidden mold, remove contaminated materials, and restore your walls to safe, dry condition.