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kandy almond
Posted: Apr 11, 2014 10:50 AM
Ok I'm getting mixed reviews on spray foam under a crawl space. A/C guy says no don't, he also said to take all insulation (fiberglass)down and just leave the plastic barrier down?! Then other people say have it sprayed! The problem we are having is our wood floors are cupping slightly from the humidity during the summers and cold in the winter but floors worry me most! We live in the gulf coast area(mobile al)! We are not by any water and the crawlspace goes from 2.5-4ft and it well vented! What to do need to try to make a decisions in the next couple of days before we get into the dead of summer!lol
Thank you so much!!
John Shockney
Posted: Apr 11, 2014 07:09 PM
Well there is a new school of thought when it comes to crawl spaces, moisture, and venting.

The old idea was to open and vent the crawl space during the summer to dry out the crawl space. The problem today is that if you have 50% humidity at 70degs that puts dew point at around 57degs, so now in the crawl space you have water lines and A/C ducts that are colder than 57 so they sweat adding to the moisture problem.

The new school of thought for the best moisture control and energy efficiency is a closed sealed crawl space. What we are doing here in Indiana is to install a 12 to 20 mill fiber reinforced vinyl moisture barrier, bringing it at least 6 inches up the walls, then spray closed cell foam sealing the top edge of the vinyl up to the bottom of the floor.

After making sure that there is also proper drainage if there is still a moisture problem a dehumidifier can be added to remove the excess moisture. But that is seldom needed.

Hope this helps

kandy almond
Posted: Apr 11, 2014 11:00 PM
Thank you so much!! Maybe this will help us with our decision!

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