How to Treat Crawlspace Mold

  • 3-6 hours
  • Advanced
  • 80-250
What You'll Need
Plastic sheeting
Mold removal chemicals
Protective clothes
Sand blaster

If your home has a crawlspace, mold growth will always be a very real concern. While there are general mold prevention techniques, the construction of a crawlspace or attic tends to negate those. They are dark, moist, and hot, so even with proper ventilation, mold can accumulate over time.

Eliminating mold is a rather straightforward process, but it will take time to accomplish. Depending on how long the mold has been there, you will need to use escalating levels of mold removal.

Step 1 - Assess Damage

Inspect your mold problem. The solution could range from a simple cleaning to a complete blasting project that covers the entire crawlspace. Wear protective gear when crawling under your home. This includes a full-body protective covering, as well as boot covers and a hood.

Step 2 - Prepare for Mold Removal

Ventilation is crucial for a job like this. Inhaling mold spores and whatever else may be floating around in the crawlspace can make you very sick. Set up fans around the crawlspace and in the vents to circulate the air, and wear a respirator mask.

Set up flood lights for better vision and lay a plastic barrier on the ground. This plastic sheet will collect the mold once it has been scraped from the joists and other surfaces.

Step 3 - Apply Mold Removal Chemicals

There are two broad types of mold removal chemicals that you can use. The first is a liquid spray that saturates the area while the second type is a foam spray which expands across the moldy surface. Chemical applications are generally used for small mold outbreaks. They will kill the mold, but you still have to scrape it from the surface.

Be sure to follow any safety instructions that are printed on the cleaning product you buy. Deviating from these instructions for both use and storage of the chemicals is dangerous.

Step 4 – When to Blast Mold

Mold that has been growing for a while and is well established may not come off effectively with simple cleaners. In this case, you will need to use a surface blaster. Mold problems tend to get this severe in homes that are vacant for long periods or homes that are poorly ventilated.

Step 5 – Using a Surface Blaster

A surface blaster is much like a sand blaster in that it will remove the mold from all surfaces by bombarding it with high pressure particles. You can likely rent or buy one from your local hardware store.

Once you’ve become familiar with the operational instructions, fire the blaster up, and aim the wand directly at the area from 2 feet away. Evenly blast the surface.

Despite the use of such a high powered machine, surface blasting mold is actually a much longer process than other options, as you will be blasting every single nook and cranny in the crawlspace. The upside is, once you’ve put in this time and work, it will completely remove every last trace of mold.

Step 6 - Prevention

Once you have removed the mold from your crawlspace, you need to protect it from future outbreaks. Install dehumidifiers to remove moisture from the air. Install adequate ventilation and periodically check the crawlspace for signs of mold.