6 Fast Steps to Get Rid of Mold in Your Crawl Space

By: Diana Rodriguez-Zaba
Updated on: August 27, 2021

The crawl space isn’t really inviting. You don’t go down there very often. Still, the whole house smells musty, and you’ve looked everywhere else. You grab a flashlight and take a peek. Right away, you can see the source of that unpleasant odor. It’s there in the crawl space.

You know how to deal with the stuff under a sink. Do you know how to get rid of mold in a crawl space?

As a DIY project, crawl space mold remediation is usually manageable, but you have to be very careful. You need personal protection gear, the right cleaning products and plenty of patience.

4 Signs of Mold in Your Crawl Space

moldy baseboards

A humid crawl space creates the perfect environment for mold. It quickly permeates wood, causes structural problems and can even impact your health.

These four clues are signs of mold growing in your home’s crawl space.

1. Strong, Musty Odors

Unpleasant mold odors continually migrate upward and through the first floor.

2. Allergic Reactions

It’s not unusual for mold under the house to cause allergic reactions, including runny noses, itchy eyes, headaches and respiratory problems.

3. Moldy Baseboards

As mold spreads from the crawl space, it affects baseboards on the floor above.

4. Discolored Crawl Space Components

Mold growing on crawl space walls, posts and floor joists appears as fuzzy, slimy or powdery patches.

Look for these color-coded clues.

  • Black – Most common molds, including Alternaria and Cladosporium
  • Green – Also very common, may be Aspergillus, Cladosporium or Penicillium
  • Greenish Black – Slimy in appearance, dangerous Stachybotrys chartarum
  • White – Variants of Aspergillus, Cladosporium and Penicillium
  • Brown – Common Aureobasidium pullulans or Pithomyces chartarum
  • Yellow – Wood-damaging Serpula lacrymans or Epicoccum nigrum
  • Orange – Variants of Serpula lacrymans

How to Kill Mold in Crawl Spaces: 6 Steps to a Cleaner Home

When we’re asked about how to get rid of mold in crawl spaces, we always stress the importance of personal protection. Before you begin any DIY mold removal project, protect your health with an OSHA-rated respirator or face mask, non-vented goggles, heavy gloves and throw-away coveralls.

crawl space mold removal chicago il

1. Assess the Situation

Wearing your protective gear, assess the extent of mold in the crawl space. Set up lights, and lay down plastic sheets to catch mold as it’s cleaned from surfaces. If the job seems too big, contact a mold remediation company right away.

2. Clean With a Foaming Spray

Spray affected areas with a foaming cleaning product specially formulated for mold removal. Allow it to expand and loosen mold, and then begin carefully cleaning surfaces.

3. Soak With a Mold Killer

Soak any remaining thin coats of mold with a homemade mold-killing mixture or mold-removal cleaner. Commercial products are usually more effective, and they often remove mold stains too.

4. Scrub Off Residue

Let affected areas dry, and then use a stiff bristle brush to scrub away any remaining mold. This can be a time-consuming process, but you want to remove as much mold residue as possible.

5. Dispose of Everything

Carefully fold up your plastic sheeting, and seal it in a heavy trash bag. Dispose of coveralls, brushes and any other contaminated gear the same way. Keep bagged items stored outside until trash pickup.

6. Control Crawl Space Climate

There are several different ways to address crawl space climate, but a dehumidifier is usually the most effective and affordable solution. Consider installing a model designed to operate in tight places. Make crawl space inspection a part of spring and fall home maintenance.

Mold in Crawl Spaces: The Health Issues

When you tackle mold in crawl spaces, it’s dangerous for the same reasons mold thrives under your home’s first floor. The area is dark, humid and badly ventilated. The conditions are ideal for a mold outbreak that can pose serious health hazards in a compact space.

Mold type is another health consideration. White mold in a crawl space is easier to remove than toxic Stachybotrys chartarum. DIY removal of this strain of black mold in a crawl space can be very dangerous to your health.

Before starting your cleanup job, think about testing the mold so that you know exactly what you’re dealing with.

How Much Mold in My Crawl Space Is Acceptable?

Mold is a natural part of our environment, but it doesn’t belong in your crawl space. Even a small patch rapidly spreads as it feeds on the structural components directly under your home.

Airborne mold spores can also migrate into the house and impact the health of everyone upstairs. There are no acceptable levels of mold in a crawl space.

Don’t Risk Your Health

crawl space mold removal

As sure as you are of your DIY talents, don’t risk taking on a job that’s too big or too dangerous. We strongly recommend calling in a mold remediation service if:

  • Affected areas include damaged or rotted wood.
  • Mold covers multiple areas larger than 3 square feet.
  • You or any family members deal with allergies or respiratory problems.

Bringing in a mold remediation specialist also addresses issues like identifying and eliminating mold sources and repairing and replacing affected materials.

How Much Does Crawl Space Mold Removal Cost?

The cost of removing mold from a crawl space ranges between $1,500 and $4,000. The figures cover mold removal and remediation as well as necessary repairs. In situations where damage is extensive and threatens the home’s structural integrity, the final cost can be higher.

6 Tips to Prevent Mold in Crawl Spaces

These six tips reduce the chances of mold invading your home’s crawl space.

1. Look for Leaks

Inspect the crawl space at least twice a year. A small leak that goes unnoticed sets up an ideal environment for mold. Check under the house after plumbing problems upstairs too. Water always flows down, so stay on the lookout.

Power Tip: Head off crawl space flooding by installing a sump pump.

2. Insulate Against Condensation

Insulation protects pipes from freezing, but it also keeps condensation from forming on pipe surfaces. Otherwise, fluctuating temperatures result in wet pipe exteriors that become a source of moisture for mold growth.

3. Fix Foundation Cracks

Dampness often finds its way into the crawl space through hairline cracks in foundation walls. Small foundation repairs head off big mold problems that can spread up and through your home’s beams and subflooring.

4. Fight Mold With Ventilation

Once fungal growth takes hold, it thrives in the wet, stale atmosphere under your home. Ventilating the crawl space circulates fresh air through the area and holds down humidity. That reduces the concentration of air-borne spores, making it harder for mold to spread.

Power Tip: Make sure the clothes dryer vent terminates outside the crawl space.

5. Install a Vapor Barrier

A vapor barrier doesn’t completely eliminate moisture in a crawl space, but it does lay down an important layer of protection against mold. The plastic membrane helps control dampness that naturally rises up into the house, affecting wood, flooring, drywall, insulation and indoor air quality.

6. Reroute Rain Water

Make sure downspouts do their job by directing their flow at least 6 feet away from the house. Add concrete splash blocks to prevent heavy rain from pooling around the foundation. These easy tips lower the chance of crawl space flooding, and that lowers the risk of mold growing under your home.

Dealing with Crawl Space Mold in Chicago, IL or Suburbs? We’re Here to Help!

If you decide to take on mold in the crawl space, removal techniques are very important, so please follow our guidelines carefully. We want you to stay safe. Wear protective gear, and take your time.

Don’t hesitate to call us if you have any second thoughts about doing it yourself. We have years of experience with crawl space cleaning services in Chicago and the suburbs. Our services cover residential and commercial properties, and our team members are industry certified in mold removal and remediation.

When the job makes you think twice, call us first here at ServiceMaster Restoration by Zaba: 773-647-1985