Reduce Condensation in a Crawlspace
LESLIE: Alright. Now we’ve got Rich in Kentucky on the line who’s dealing with a condensation issue.
Rich, how can we help you?
RICH: Went in the crawlspace last year to run some wire and I got all this water. And it’s on the heating and air ducts. And it’s nice, fresh, clean water dripping on the vapor barrier. When I bought the house, the two vents that are down there are blocked. They might have did that when they put in the radon vapor-barrier system.
So, basically, I was mopping it up with a towel and putting it in the bucket to get it out of there and I was just – same thing’s going to happen this summer when I run the air condition, I guess.
TOM: This is a crawlspace that’s unfinished and you have a radon ventilation system in the crawlspace or it’s a basement?
RICH: The radon’s in the basement but I thought there was a tube going into the …
TOM: OK. Because it typically – here’s what you’re going to do. With a radon system, the basement, if it’s finishable, it’s going to be sealed and have a ventilation system installed into it. The crawlspace is usually – you never put a radon system in a crawlspace because a crawlspace is always vented.
And if the crawlspace is open to the basement, then if anything, you might seal off the space between the crawlspace and the basement to create two separate and distinct areas that have their respective levels of ventilation. Does that make sense?
RICH: Yeah, I think it’s pretty much blocked off. I guess the radon doesn’t go in there then.
TOM: So now let’s talk about your moisture problem. Now, what you’re seeing in the ductwork is condensation, because the ducts get cold when you run air conditioning. And you have warm, moist air in the crawlspace area and that condenses on the outside surfaces of the ducts and they drain. Basically, they drip.
So, what can you do about that? Couple of things. First of all, we can take some steps to reduce the amount of humidity that you have in the crawlspace. So how do we do that? Well, number one, I want you to look at your gutters outside. Make sure that the gutters are clean, free-flowing and discharging away from the house. We want no water collecting anywhere near the first 4 to 6 feet away from that foundation.
LESLIE: Because that’s just going to find its way right back into your crawlspace.
TOM: Exactly. Big U-turn.
TOM: Then, look at the slope of the soil and make sure that the soil slopes away. And make sure the gutters are finally clean. So if all that water from the rain is moving away from the house, that’s good.
The next thing that you can do is you can make – that those ventilate – that those vents are open in the crawlspace. And then thirdly, you can add a dehumidifier. Take a look at the Santa Fe dehumidifiers. They’re best in the business; they are Energy Star-rated, so they’re not going to cost you an arm and a leg to operate; and they’re going to totally dry out that crawlspace. And then the fourth thing that you can do is insulate the ducts.
So, drainage on the outside, open up the vents, get a Santa Fe dehumidifier and then insulate the ducts. And that will stop the problem.
RICH: OK. That’ll work. Thanks for the answer.
TOM: You’re very welcome. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.