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Ask Mr. Crawlspace

Why do I need a vapor barrier in my crawl space?


Vapor barriers protect your home against damaging moisture from condensation. By preventing moisture from rising up from the earth and gathering beneath your home, you are controlling problems caused by excess moisture such as wood rot, buckling floors, mold, musty smells and other concerns that could affect the value of your home and your health.

Benefits of vapor barriers

  • Energy Efficiency
  • If you have a dirt crawlspace, the humidity levels in your home are higher and damp air is more difficult to heat and cool. This can cause your HVAC system to run more often as it tries to keep the temperature comfortable. Properly installing a vapor barrier reduces rising damp reducing the load on your HVAC. There is a big opportunity for savings when you close your crawl space. By sealing and insulating your crawlspace, you prevent cold floors and reduce drafts from below, keeping your home comfortable.
  • Limits Dampness
  • Water and moisture can seep through walls and the dirt floor under your home. The dark and damp environment promotes mold and mildew growth. Installing a vapor barrier deters the moisture from entering your home and prevents subsequent costly damage to the structure caused by rotting wood, rusted metal and damaged insulation. A dry and sealed crawl space prevents moisture from entering the wood floor joists, assists with keeping pests from getting in and keeps hazardous mold spores away from your family’s lungs.

    Can I install a vapor barrier myself?

    Absolutely! Installing a vapor barrier is not a complicated or terribly expensive project. However, it can be difficult physically depending on the amount of crawling you will need to do. Additionally, you may want to enlist the help of one other person to help the project go faster and easier. You will want to assemble all your materials in advance. Suggestions for what you’ll want on hand include a hammer, caulking adhesive, caulk gun, Bora-Foam termite resistant insulation, seam tape, utility knife, fabric stakes, or sod spikes, vapor barrier(8 mil– 20 mil is most commonly used). Be sure the area is clean and dry before you begin installation. Feel free to watch our installation videosfor full instructions.

    Moisture damage from condensation is no less worrisome than moisture damage from leaks. A vapor barrier can provide the protection you need. Call on Crawlspace Depot for the supplies and advice you need. We are the experts in moisture management.

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