I was looking into "encapsulating" my crawlspace by some manner or other. From what I can tell the way to do this involves (primary) some thick poly (.15 or more) along the the soil and up the walls. The poly is then sealed to the walls.

Currently my crawlspace is vented.

Whilst I was doing my research I stumbled upon a vapor barrier paint. Would this paint be a suitable substitute for a poly barrier? Or should I not even worry about that and just use a poly barrier?

My crawlspace floor is dirt and is almost entirely below grade.

  • 1. Where did the idea of "encapsulating a crawlspace" come from? 2. Any decent coating product is likely to be expensive and difficult to properly install. It is also unlikely to be intended for "encapsulating a crawlspace". 3. The solving the issues mentioned in your other post involve basic building science.
    – user23752
    Sep 15, 2014 at 16:25
  • What's wrong with polyethylene plastic? Paint's a pretty poor substitute for what polyethylene's meant to achieve which is to limit surface evaporation to a level that the venting can handle. Since the crawlspace likely is dirt (not mentioned), paint needs a stable substrate like concrete. Sep 15, 2014 at 17:11
  • @FiascoLabs Nothing in particular, just thought it might be easier to put up, particularly in certain areas of my crawlspace.
    – iamkrillin
    Sep 15, 2014 at 17:12
  • @FiascoLabs Also, I was thinking of using it only on the cinderblock walls
    – iamkrillin
    Sep 15, 2014 at 17:28
  • If the cinder block is below grade and weeping moisture, the best would be to put in a perimeter drain and lower the water table. If it's currently dry during the wet season, you probably won't gain that much. Sep 17, 2014 at 3:43

1 Answer 1


Check out information on basement and crawl space strategies on the buildingscience.com website. Also, check your local codes. Some jurisdictions still require methods that are not scientifically correct, and some have requirements related to storm surge and flooding. If you dig a little, some have work-arounds for both scenarios that are more energy efficient.

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