How To Remove Mold From Crawl Space Yourself

How To Remove Mold From Crawl Space Yourself (DIY Steps)

Do you think you have a mold problem in your crawl space?

You may have noticed mold growth after a recent heavy rain or snow fall but this doesn’t mean that mold isn’t already present under your house where you cannot see it.

Mold can grow in the smallest of spaces; an example of this would be a crawl space under a house or any other type of residential building.

Mold are known to cause allergic reactions and respiratory problems when inhaled. So it’s important to not only care about stopping the mold growth in your home, but also outside the living space as well.

Mold prefers dark places with high humidity levels, like underneath the house where no light penetrates. This means that, if your home has a crawlspace, mold could be growing unnoticed.

Why Does Mold Grow in Crawl Spaces?

Mold in Crawl Space picture
Picture of Mold Growth in Crawl Space

The mold that grows in crawlspaces is a serious concern for homeowners.

There are many different factors that contribute to mold growth in this area. To mitigate mold growth in your home’s crawlspace, you should keep moisture levels low and ventilation high.

Also, you should ensure that all moisture problems are addressed.

If you fail to fix the issue, the mold growth will continue. Mold is frequently found growing in crawlspaces that have moisture problems such as the following:

  • Leaky plumbing in the crawlspace or moldy insulation underneath your home.
  • Molds can also grow in crawlspaces because of poor ventilation. The mold spores can grow and thrive if they have access to the perfect conditions: moisture, darkness, and food sources (such as wood or insulation). Crawl spaces underneath your house should always be properly ventilated with approximately 50% relative humidity; this will ensure mold does not have enough water content on which it can feed upon.
  • Water accumulation under crawlspaces from improper drainage around the building. A common cause is if the downspouts discharge water next to the building foundation. Over time, the water seeps under the structure and is trapped.
  • Lack of vapor barrier on the subgrade of the crawl space. When the moisture barrier is damaged or not installed, this can lead to elevated humidity levels in the crawl space that in turn provides a good atmosphere for mold to grow on joists and support beams.

Signs of a Mold Problem in your Crawl Space

When mold begins to grow, it looks bad, smells bad, and can also be a health risk for the people living in the home.

Mold loves warmth and thrives when there is moisture present; mold needs four things to grow:  A food source (such as wood or paper), Warmth (around 75 degrees Fahrenheit), Moisture-soaked material and enough time.

Anything that you see growing on your crawlspace flooring could be mold. It might look like black spots or green slime with furry edges but mold comes in many colors including white or greyish blue.

The most common signs of mold growth include:

  • Dark discoloration on wooden beams.
  • Crawlspace will usually have an earthy, musty smell.
  • Building materials have signs of water damage.
  • Discoloration on insulation.
  • Floor trusses or joists that appear to have dry rot.

Another sign is sagging floors. This occurs when the mold damage is excessive, and the materials are deteriorating. In severe cases, you could see mold beginning to grow on flooring or base trim inside the home.

Removing Minor Mold Growth From Crawl Spaces

The first step is to assess the damage and the area affected by mold growth. 

If the area is large, generally more than 10 square feet, its recommended you get a mold remediation professional to do the job correctly. 

  • Remove moisture quickly (within 24-48 hours). Use dehumidifiers and fans to assist in the dry out process. (Be cautious of applying heat to wooden materials to aid in the dry out process).
  • Find and address the cause of the growth – this could be a leak or other moisture issues.
  • Ensure that adequate ventilation is provided in the area. Ventilation is important in helping to circulate air through the crawlspace. If no ventilation is provided, set up fans to ensure there is ventilation during the entire process.
  • Put on your gloves, mask, and eye protection.
  • Begin by applying the detergent to the section of the wood with mold growth. Always avoid oversaturating the material. Oversaturation could worsen the condition
  • Begin to clean the wood using a stainless-steel scrubbing pad or a thick bristle or wire brush. Scrub until the area looks visibly clean.
  • After the area has been scrubbed and molds have been removed, use a clean cloth to dry the area.
  • Sanitize the wooden materials. Sanitizing helps to kill any remaining spores on the material. The type of biocide used should be approved and listed by the EPA.
  • Dry the wooden materials again, then use a HEPA vacuum to clean the wood and the surrounding area. After vacuuming, you can apply a mold inhibitor if you choose to; however, adding an inhibitor is not necessary.
  • Place a fan in the crawl space and allow the area to dry for 24 hours, this will remove excess moisture from the wood generated by the cleaning process.

After 24 hours, assess the area and repeat the process if necessary.

To further prevent regrowth, installing dehumidifiers and ventilation will help reduce the humidity in the crawlspace.

Additionally, installing a layer of 6 mil poly on the subgrade of the crawlspace will also assist in reducing moisture and high humidity levels.

Checking gutters and downspouts to ensure they are in good condition; and making sure that when it rains, water drains away from the crawl space are also the methods that can reduce water ponding in the crawlspace that can promote mold growth.

If mold growth continues despite having taken steps from the above-mentioned list, then consult an expert for further help or advice on how best to proceed with mold remediation and prevention.  

Nowadays many companies provide services regarding both mold inspection and mold removal services.

Mold infestation is something no homeowner must take lightly.

Mold spores can cause allergic reactions and respiratory problems when inhaled, so ensure that the areas under your home which may be prone to humidity build up have proper ventilation.



More Mold related content

Suspect mold in your home? Use this simple checklist to find it's source