Case Study: Hidden Black Mold Behind a Stamford Drywall Cavity, CT

The Stamford family had been chasing a musty smell for months. They tried air fresheners, dehumidifiers, even ripped out a section of carpet — nothing worked. When the youngest child started experiencing chronic congestion, they called us.

Our same-day inspection used non-invasive thermal imaging to find a band of elevated moisture along the back basement wall. We pulled an air sample (chain-of-custody to a third-party lab) and a surface sample. Lab results 48 hours later confirmed Stachybotrys chartarum — true black mold — at spore counts more than 10× the outdoor baseline.

The cause was a slow exterior foundation leak combined with a finished basement built without a vapor barrier. Mold had colonized the back of the drywall over months, completely invisible from inside the home.

We set up full IICRC S520 containment: 6-mil poly sheeting with zippered access, two HEPA air scrubbers maintaining negative air pressure, HVAC sealed off. Crew worked in N-95 PPE. Demolition removed 240 sq ft of contaminated drywall, insulation, and carpet pad. Framing was treated with antimicrobial encapsulant.

Day 9 third-party clearance testing showed spore counts below outdoor baseline. We rebuilt drywall, insulation (this time with proper vapor barrier), and finished the wall.