Ventilating vs Nonventilating Crawlspace
OK- I’m knee-deep into the issue of vented/non-vented 3 crawlspaces under our house. Area 1 has two 8″ X 16″ vents and a ground cover (polysheet). Area 1 has no mold or odor problem that I have detected.
There are two additional areas with no vents. Area 2 is a 20′ X 20′ bedroom with bad floor insulation (rodent destroyed)and no ground cover. This area also has developed a light covering of mold/mildew on the undersides of the flooring and joists. We can smell a slight moldy odor on the carpet above. I want to a) stop the mold and treat the wood below to prevent recurrence and b) vent or nonvent, depending on what the current wisdom recommends. I live in upstate NY, in which the climate has become more moist since living here 40+ yrs.
Please advise.
Don’t even ask about Area 3. That’s for another time.
BTW- all three areas are connected by adjoining cinderblock walls, but at present there are no intended openings between them.
Thanks.
Bill
Replies
How many vented basements have you seen? Seal it, condition it, and put plastic on the ground to deter moisture from the ground, live a happy life not worrying about frozen pipes.
I just asked about venting here. If you cover the ground with plastic you shouldn't have a problem. It keeps the moisture way down.
I'm OK with that, but I took a look at a couple of articles online that suggested a vented crawlspace can pick up outside humidity and the moisture can condense on the floor joists, etc.
I'm ready to punch out a few cinder blocks and install vents- and of course lay down a poly barrier on top of the ground. Sure wish the contractor had done it.
Thanks.
Bill
Been there and did that at our old house. We had moisture problems under there and lots of mold. I added vents like they were on sale but it didn't help, and in fact got worse. We ended up getting someone to come in, remove the mold and turn it into a clean space, which blocks off the vents totally. Since the crawl space is cooler than the outside, when the vents are open, hot air (and the accompanying humidity unless you live in the SouthWest) comes in.
Please see this article on moisture in crawlspaces: http://www.docair.com/DocAir/article_050208_WhyMoldInCrawlSpace.asp
Barry Westbrook in Nashville Tennessee is a specialist in indoor air quality and has done extensive work in the area of moisture in crawlspaces......according to his work, any ventilation under a crawlspace will result in an increase of moisture under a house......then, if the temperature and dew point hit certain levels, moisture condenses on all surfaces, contributing to the proliferation of mold/mildew on floor joists, insulation and everything else under there. He feels that there is strong evidence against doing any ventilation in a crawl space.
Roger