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Condensation in crawlspace insulation.

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Can I put vapor bar. between subflr & underlay to stop condensation in insul'n over crawl space
asked in Crawlspace Inspection by gerry (140 points)
edited by darekrudy
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1 Answer

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Hi Gerry,


I'm not sure if I'm getting that right, I would need more information about your crawlspace. Does it have finished floor (concrete), if not, is there a lot of moisture, standing water, is it heated or not / what’s the temperature in the crawlspace, what is your climate / where are you located, are there any crawlspace vents to exterior (open or closed), do you have any appliances in the crawlspace (furnace, water heater) etc.
If I understand correctly you have insulation (fiberglass batts?) installed between the floor joists (crawlspace’s ceiling), that insulation is exposed towards the crawlspace (no vapor barrier, plastic, paper, aluminum foil, plywood or any other material covering it) and there’s condensation building up inside that insulation?
If this is the case and (for example) you have unfinished floor (dirt, gravel), the first thing I would suggest is sealing it with thick plastic foil or membranes designed specifically for that purpose.
You may want to look at a one of mine articles (unless you did that already) - http://checkthishouse.com/1537/crawlspace-inspection-part-eight-mold-ventilation-and-insulation.html
answered by darekrudy (21,730 points)