Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 8/13/2013

eastern nc crawlspace, no basement, vented, but moisture. how do I dry it out...adding a vapor barrier now....

even with adding a vapor barrier, how do I keep it dry? I was told the humidity is high in this area and the condensation from the AC causes the problem. Wish I had built on a slab!!

Do you have the same question? Follow this Question

3 Answers


Something doesn't ring true here - do you air condition your crawlspace ? If so, you need to get that area out of the air conditioned space. If not, then air conditioning has nothing to do with it.

High humidity itself will cause condensation on the colder foundation concrete or block, resulting in moisture on the walls and possible mold formation. Putting in the vapor barrier (presumably plaxed on exposed earth ?) will certainly help, though you need to be sure it has a positive vapor-tight seal with the foundation to be much help.

If that is not enough, in most cases adding ventilation will bring the problem within reasonable levels - if natural ventilation through screened wall vents won't do it, then perhaps a permanently installed low-speed fan (about 24-36 inch usually) is necessary to pull air through the space. If you have significant exposed concrete wall and the outside dirt is commonly moist that should be sealed with a water-barrier sealer like an epoxy paint or hydroseal, as concrete passes a lot of moisture to dry spaces.

Read through the Home > Basement Waterproofing comments for the past couple of months - about 90% of the time the solution is removing the outside source of the water rather than trying to control it once in the basement/crawlspace, though the vapor barrier is a good idea regardless.

Answered 7 years ago by LCD


Where exactly is the condensation occur? If it is on the walls and floor you either have a leak or I should say major leaks in the ducts. It is also possible that there is a vent that is open to the crawl space that should be closed during AC season and can be left open in the winter. Old time HVAC guys sometimes cut a hole in the top of the duct for heat to escape to keep the floor warm. They would get less call backs because if the floor is kept warm they had less complaints. I also wonder if AC was added to a heat only system and if the ducts are insulated causing condensation on them. You should definitely check for leaks especially on the supply side for energy loss and on the returns because you may be transporting mold into the living space.

Answered 7 years ago by ContractorDon


Condensation from the A/C???? so the condensation line from the air handler drains into the crawl space??? find another contractor..

Your problem is caused by the crawl space ventilation- the warm mosit air enters the crawlspace area and condenses causing all sorts of moisture problems.

First- if it is a dirt floor- SEAL IT

Second- seal the concrete wall/floor to prevent moisture vapor through the concrete


Forth: Spray foam insulation the walls, seal any air infiltrations into the living area The foam insulation will keep the moisture out and minimize any condensation.

Answered 7 years ago by hosey

Related Questions

Terms Of Use
Privacy Policy