You use a HEPA-filter vacuum, dust religiously, and buy allergen-free products. For some reason, though, the air in your home still makes you wheeze or suffer other asthma-related symptoms. To paraphrase a line from a famous horror story, the call may be coming from inside the house; or rather, the allergens aggravating your allergens may not be floating in from the outside but may be migrating upward from the crawlspace under your home. Here's more information about this problem and what you can do to fix it.
Moisture Plus an Enclosed Space Equals Mold
Crawlspaces are designed to provide access to necessary fixtures in the home that would normally be placed in a basement, such as the gas hook-up, electrical system, and plumbing. These spaces are supposed to be sealed to prevent moisture from getting inside, but this isn't always the case, especially for older homes that may have been built with vented crawlspaces.
What happens is that moist air enters the area and comes into contact with floorboards or other spaces that may be cooler than the temperature of the air. As a result, condensation will usually form. Over time, this excess moisture seeps into the structural elements of the crawlspace and creates the perfect environment for mold, mildew, and fungus to grow. As an unfortunate side effect, these organisms find their way into the home, aggravating breathing conditions like asthma and leading to other medical problems such as skin rashes and infections.
That's not the only issue excess moisture can cause. If the issue is not fixed, the water can weaken and rot the beams and concrete, leading to all sorts of structural issues with your home. This is a particular problem if you live in areas where flooding is common and your crawlspace does not have an adequate drainage system to deal with the excess water.
Crawlspace Moisture Management
If you suspect mold may be in your crawlspace, the first thing you need to do is have the area inspected and treated. Dealing with the moisture problem in your crawlspace may involve waterproofing the area using a special sealant, and the last you want to do is trap the mold and fungus in the walls and structures. While you can tackle the project yourself, it may be best to have a professional do the job for you. Eliminating the mold may involve dismantling walls and pulling up the floor, so you need to decide whether that's something you really want to be doing.
Once the mold has cleared, there are several things you can do to keep your crawlspace dry and prevent the mold from returning. If your crawlspace has vents that open to the outside, you'll want seal them to prevent air and water from entering into the space that way.
Another thing you can do is waterproof the walls. Sometimes moisture will enter the crawlspace through small cracks in the concrete, especially in areas by downspouts that drain the water into the ground near the crawlspace. You can usually tell this is the case if the walls bulge in areas or there are noticeable breaks in the concrete. Coating the walls with a waterproof substance such as a silicate-based concrete sealer can prevent water from seeping inside the space.
If your home is subjected to flooding, it's critical to either have the crawlspace outfitted with a proper drainage system that funnels water out of the space or put in a sump pump that will channel the water into other parts of your yard. This will minimize the risk of having pools of standing water sitting in your crawlspace for weeks at a time.
Lastly, you'll want to put a dehumidifier into the area to help keep the space dry. If you already have a whole-house dehumidifier, it may be worth the cost to have a contractor install a vent that connects to the appliance so it can treat the crawlspace in addition to the rest of the house. Otherwise, a regular room dehumidifier may also work well. Just be sure to install it in an area where it won't come into contact with water.
For more information about keeping moisture out of your crawlspace or help fixing damage caused by water, contact a crawlspace repair company such as Perma-Dry Waterproofing & Drainage, Inc.