You Cannot Clean It Out of Drywall The Material Has to Come Out
Mold that is visible on drywall has penetrated the paper face of the drywall. Drywall paper is cellulose the same material mold uses as a food source. Once mold has colonized the paper face of drywall, the material is contaminated at depth. Cleaning the visible surface with antimicrobials kills what it contacts on the surface while leaving the colony intact in the paper and the gypsum core. The colony re-establishes from the interior within weeks. There is no effective way to remediate mold in drywall without removing the material.
This is one of the points where homeowners most often get sold an inadequate fix. Companies that spray and encapsulate mold on drywall and declare the job complete are leaving an active colony in place covered by a coating. The IICRC S520 standard I co-authored is explicit on this: contaminated porous materials that cannot be cleaned to the standard require removal. Drywall with mold on its surface is in that category.
How Far Does It Extend
Visible mold on drywall is always accompanied by mold in the wall cavity behind it. The moisture that created the surface growth penetrated through the drywall. The back face of the drywall and the framing behind it were wet before the front face showed growth. In most cases, both the drywall and the insulation behind it require removal. Framing is assessed after removal and treated if affected.
A homeowner in Paradise had a company spray and paint over mold on two bathroom walls. Six months later the smell was back and discoloration was showing through the new paint. We opened the wall. The colony had continued growing behind the coating. The framing had additional deterioration that had developed during the intervening months. The correct scope the first time would have been less expensive than the second remediation plus the intervening property damage.
What We Do
We remove affected drywall and insulation, dry the framing to IICRC S500 target moisture content, treat with antimicrobials, and run air sampling before reconstruction to confirm clearance. We coordinate the reconstruction. Read more about our mold removal service. Call (702) 442-1126.