Mold Remediation: Moisture Control, Containment, and Clearance
Scope and first principles
Mold remediation is moisture management, not a spray-and-wipe task. The exam tests whether you can assess a loss, set containment, select PPE, remove contaminated material without spreading spores, verify drying, and document clearance. EPA guidance treats mold as a moisture problem: find and fix the water source before remediation, because mold returns if the substrate stays wet. Small areas (often defined as under about 10 square feet) may be cleaned in-house; larger or hidden growth, HVAC contamination, or sewage-related water calls for a planned remediation with containment.
Core rules
- Classify condition: normal, settled spores, or actual growth. Actual growth on porous materials usually means removal, not cleaning.
- Establish containment and negative pressure where disturbance is likely; protect occupants and HVAC.
- Use PPE appropriate to the task: at minimum gloves, eye protection, and a respirator rated for the expected exposure; use greater protection for large or confined jobs.
- HEPA-vacuum and damp-wipe nonporous surfaces; avoid dry sweeping and ordinary fans that aerosolize spores.
- Dry structural materials to documented moisture targets before clearance. Clearance is visual plus moisture verification, with air sampling only when the project plan requires it.
Worked example
A classroom has about 30 square feet of visible mold on drywall below a roof leak. Reason it through: the area exceeds the small-scale cleanup threshold, and drywall is porous, so cleaning the surface is not enough. Stop the leak, isolate the room, remove and bag the drywall, HEPA-vacuum the cavity, clean adjacent nonporous framing, then dry and verify moisture. Do not clear on a "no mold visible" look alone if the assembly is still wet.
Traps
Killing surface mold without correcting moisture; skipping containment; using ozone or bleach as a substitute for removal; clearing while materials remain damp; and treating air sampling as a pass/fail substitute for visual and moisture inspection.