Attic Mold Remediation: Causes, Removal & Prevention

Attic mold surprises a lot of homeowners — it's out of sight until a roofer, inspector or buyer's agent spots it. The good news: it's almost always a fixable ventilation and moisture problem.

What causes attic mold

• Poor ventilation — blocked soffit or ridge vents trap warm, moist air against cold roof sheathing
• Bathroom or dryer fans venting into the attic instead of outside
• Roof leaks introducing water directly
• Inadequate insulation letting warm household air condense in the attic

How attic mold is removed

1. Inspect the sheathing, rafters and insulation, and find the moisture source
2. Set up containment and HEPA filtration
3. Remove mold from wood surfaces and treat them; replace severely affected materials
4. Correct the ventilation or leak that caused it
5. Verify the area is clean and dry

Preventing it from returning

Make sure soffit and ridge vents are clear, fans vent outside, and insulation is adequate. For active growth, professional attic mold removal handles both the mold and the cause.