Small mold patches on tile grout, bathroom caulk, or window frames can usually be cleaned DIY without professional help. Mold inside walls, in HVAC ductwork, or covering more than ~10 square feet should not.
Safe DIY scope
- Less than 10 square feet of visible mold
- On non-porous surfaces (tile, glass, metal, sealed wood)
- Visible mold only — not behind walls or in cavities
- You're not in an at-risk health group (immunocompromised, asthmatic, infant)
DIY method that works
1) Wear N95 mask + gloves + eye protection. 2) Mix 1 cup white vinegar in 1 gallon water. 3) Apply to mold, scrub with brush, wipe clean. 4) Repeat with a mold-resistant primer. 5) Open windows during and for 4 hours after.
Call a pro instead if any of these
- Visible mold on drywall, insulation, or other porous surfaces
- Musty smell with no visible source (probably behind a wall)
- HVAC running musty smell
- Mold after a water event (insurance won't cover DIY)
- Anyone in the home has respiratory issues or is immunocompromised