A friend has a cabin built in the 1980s in the foothills of the Adirondack Mountains. It sits on a foundation with a roughly 30" height crawl space. The surface of the crawl space is bare ground while the foundation enclosing it is insulated with 1 1/2" polystyrene. There is a high efficiency propane fired furnace suspended in the crawl space. The house's humidity level is consistently high unless a dehumidifier is run regularly . Obviously the situation would be improved if a good vapor barrier was installed. The head space is too low for one to pour a rat slab so it looks like the easy solution would be to simply lay polyethylene sheet on the ground but I worry about its durability/longevity.

I'm looking for suggestions regarding specific products more method of application to minimize upward movement of vapor. . Thick poly alone? Thick poly covered with some screened sand for protection?

Thanks for any ideas.

Hugh

Please look at www.barrett-inc.com/thebarrier/php This is made to do exactly what you are talking about and comes in 3 different thickness.

Lot's of options for vapor barrier. Since you need regular furnace access, go with 20 mil thickness. No recommendation on whether you need additional insulation. Other may chime in. Make sure though that you have a priority on ensuring the band joist is well sealed.

Posted By mtrentw on 08 Nov 2017 02:53 AM
Lot's of options for vapor barrier. Since you need regular furnace access, go with 20 mil thickness. No recommendation on whether you need additional insulation. Other may chime in. Make sure though that you have a priority on ensuring the band joist is well sealed.

Thanks for the input. We'll seek out 20mil with rip-stop if available.

Hugh

Stego products have a system for this, go to a concrete contractors supply house for options, you can usually buy over the counter.

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