What should you do when demolition uncovers mold?
Short answer. Stop work in that area, photograph it, tell the homeowner at once, and get a professional assessment and certified remediation before resuming. Cover the added cost with a written change order; never tile over it.
Work it through
You're the contractor. Pick what you'd do, then see how each choice plays out.
While demolishing a bathroom wall, your crew discovers significant black mold behind the tile — likely from a slow leak that went undetected for years. The homeowner's contract is for a cosmetic bathroom renovation.
The mold remediation will add $4,000-6,000 to the project.
- Correct
Concealed mold is a changed condition that requires immediate disclosure and professional remediation. Do not disturb it further — mold spores become airborne when disturbed. You need: (1) stop work in affected area; (2) photo documentation; (3) immediate homeowner notification; (4) professional mold assessment; (5) certified mold remediation before you resume. A written change order covers the additional cost. Hiding mold behind new tile is negligent and creates massive future liability.
- Dangerous and negligent
Bleach doesn't kill mold on porous materials like drywall and wood. Tiling over active mold traps moisture and allows continued growth behind the wall. When the homeowner or a future buyer discovers mold spreading behind your 'renovation,' you face: health liability (mold causes respiratory illness), construction defect lawsuit, MHIC complaint, and potential fraud charges for knowingly concealing a hazardous condition.
- Wrong
You cannot visually distinguish between mildew and toxic black mold. Downplaying the discovery to avoid a change order is dishonest and puts the homeowner at risk. Professional mold assessment is needed to determine the species and extent. If it's Stachybotrys (toxic black mold), improper handling exposes your crew and the homeowner to serious health hazards. Disclose, assess, remediate professionally.
All 9 job-site safety & hazardous materials questions
- When does OSHA require guardrails on scaffolding?
- What does the EPA RRP rule require when you find lead paint?
- Can you remove suspected asbestos during a renovation?
- What should you do when demolition uncovers mold?
- How must renovation debris be disposed of?
- Are you liable for weather damage to an unprotected job?
- Are you liable when someone slips on ice at your job site?
- What hours can construction start in a Maryland neighborhood?
- What should you do when your crew damages a neighbor's property?