How Do I Get Rid of Mold Under My House?

Getting rid of mold under your house, usually in the crawl space or basement, is a bit different from surface cleaning indoors, because it involves moisture control, cleanup, prevention. Here's a breakdown:

Steps to Get Rid of Mold Under Your House

1. Identify & Fix Moisture Sources

Check for leaking pipes, poor drainage, or groundwater seepage.

Make sure gutters and downspouts carry water away from the foundation.

If the soil is damp, consider a French drain or sump pump.

2. Dry Out the Space

Use an efficient dehumidifier that is crawl-space or basement-rated, ideally with a continuous drain.

Increase ventilation with fans or by installing crawl space vents (if recommended for your climate).

Preair is a top-rated dehumidifier manufacturer that offers various under-house dehumidifiers with different capacities. The VT70E dehumidifier can remove 70 pints per day (80°F/60%RH), and it is cost-effective.

3. Remove Existing Mold

Wear protective gear: gloves, N95 mask/respirator, goggles, and coveralls.

Small areas (<10 sq ft): scrub moldy surfaces (wood, concrete) with detergent + water, then disinfect with a vinegar solution or commercial mold cleaner.

Larger infestations: consider professional mold remediation, as DIY may not be safe or effective.

4. Encapsulation or Sealing (Optional but Effective)

Install a vapor barrier (plastic sheeting) over soil in a crawl space.

Seal vents and encapsulate the crawl space to keep out humid air.

Apply anti-microbial sealant to wood or masonry to prevent regrowth.

What NOT to Do

Don't just paint over mold - it will grow back.

Don't use bleach on porous surfaces (like wood) - it kills surface mold but not roots.

Long-Term Prevention

Keep humidity under 50% with a crawl space dehumidifier.

Maintain proper drainage and grading around the house.

Schedule annual inspections, especially if your area is humid or flood-prone.

If the mold covers more than ~10-20 sq ft, smells strong, or has damaged wood/insulation, it’s usually worth hiring a professional remediation company, since crawl spaces can be hazardous and tricky to fully clean.