Waterproof Insulation: How to Protect Your Crawl Space Against Moisture

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    20 April, 2022

    If your house has a crawl space, you should ensure it has functioning waterproof insulation. A wet crawl space exposes you to poor indoor air quality and becomes a breeding ground for mildew and mold, which cause damages such as wood rot. Here are some solutions to protect your crawl space against moisture.

    Quick Guide to Keeping Your Crawl Space Dry

    Moisture seepage in your crawl space compromises your home’s structural integrity and air circulation. Consider these tips to help you keep your crawl space dry:

    Install insulation

    A well-insulated crawl space keeps your home warm and saves on energy costs. Insulation also seals off rodents and insects. So, what are the different types of insulation available on the market? Some moisture-resistant insulation types you can install in your crawl space include:

    • Foamboard
    • Spray foam
    • Fiberglass, and
    • Blown-in insulation

    Prevent Water from Penetrating the Crawl Space

    Water may seep into your crawl area if the soil slopes towards the foundation. Therefore, ensure the ground slopes away from your house.

    Eliminate Puddles or any other Moisture Source

    Use a sump pump to drain water to the lowest point of your crawl space. Get a professional to inspect the pipes under your house for plumbing leaks.

    Declutter Your Crawl Space

    Clean and remove debris from your crawl space to keep good air circulation and reduce dampness.

    Inspect for Damage and Repair

    If you intend to keep your crawl space free of moisture, make regular inspections to ensure there are no extreme damages to the foundation of your house. Here’s what to check during an inspection:


    Check for leaks in the HVAC ducts and plumbing system, which may drip water into your crawl space. Your plumbing expert can install water-resistant insulation and repair the system in case of damage.

    Holes and Cracks

    Holes and cracks can let cockroaches, mice, and other pests and insects into the crawl space. Small animals and insects can chew and cause tears on wooden structures and electrical wires. Seal holes using wood, foam insulation, or caulking to keep pests at bay.

    Cover Vents

    Open vents in crawl space allow pests, air, and water to access your home. As a result, your house is vulnerable to flooding, damage to the internal support structure, and pest infestation. Such problems compromise the stability of your house and cause health issues to you and the inhabitants of your home. Open vents also lead to an increase in energy bills.

    To prevent further damage to your crawl space, seal all vents with airtight covers. With a sealed crawl space and waterproof insulation, you reduce heat loss in winter, saving your energy bills. 

    Position Gutters and Downspouts Properly

    Downspouts discharge water from gutters. If downspouts face your house, water could flow back to the house when it rains. The water can flood your basement and destroy your landscaping. Your downspouts should face away from your home to prevent these and more damage.

    For further caution, add long downspout extensions to lead water farther away from the house onto the yard or into a drain. Finally, clean your gutters regularly to keep them free of leaves and debris.

    Install A Sump Pump

    In addition to using moisture-proof insulation, you can install a sump pump to improve the drainage system in your crawl space. A sump pump drains water collected in a bucket or basin outside the home, leaving your crawl space dry.

    Since they are mechanical devices, sump pumps may fail, leading to flooded crawl space or basement and a high repair cost. Therefore, inspect the sump pump in your crawl space frequently for timely repairs in case of damage.

    Final Thoughts

    A wet crawl space means poor air quality and expensive repairs. However, you can avoid the inconveniences of a damp crawl space by installing moisture-resistant insulation in your home. At Insulation Co., we install moisture-proof insulation to help protect your crawl space against moisture, keeping your home energy efficient and healthy to live in. Contact Insulation Co at 425-903-6453 for more information on our services.