Fix a Buckling Floor Caused by Humidity
LESLIE: David in Florida finds The Money Pit on WCOA. And you’ve got a problem with your floor. Tell us about it.
DAVID: And when it … we’d pull that up, it would be a white, stringy mold type stuff. And some places, there was moisture on top of the subfloor and there are some places that are now rotten – dry rot type rotten – where it wasn’t before. Now I understand that’s got to be replaced.
TOM: It sounds like there is a moisture problem in the crawl space. And there’s a couple of things that you can do to address this. You’ve got to lower that humidity and sometimes you need a little mechanical help, in Florida, to do that.
The first thing I would suggest is the basics and that is to look at the grading and the drainage at the foundation perimeter. Even though you may have sandy soil that’s very absorbing, you want to make sure that the soil slopes away from the walls, that the gutters and downspouts are extended out away from the foundation at least four to six feet.
The next thing you want to do is to look inside the crawl space and make sure you have a plastic vapor barrier across the entire floor. Use as few seams as possible and that stops the soil moisture from evaporating up.
And the third and final thing that you could do to keep moisture down in that space is to install a crawl space vent fan – and this is one that would fit inside the same space in your foundation that is (inaudible) reserved for foundation (inaudible) – that eight inch by sixteen inch space – except that it is wired to a humidistat, not a thermostat. So whenever the humidity gets high in the crawl space, the fan kicks on and pulls drier air through to dry out that space.
All those things will work together to reduce moisture. I have found that parquet floor is very unforgiving to moisture and humidity. Because once it starts to swell, it pops up and comes apart like a jigsaw puzzle and you just can’t get it back together again.
DAVID: Yes sir. Okay, when I had the plastic put down … they put down plastic and said I need to have gaps in it.
TOM: That’s not correct.
LESLIE: No, it needs to be pretty overlapped.
TOM: (overlapping voices) You have no gaps. In fact, you should tape the seams.
TOM: You want to have no gaps in there. The whole idea is to have no gaps …
LESLIE: (overlapping voices) To stop the moisture from coming up.
TOM: Right. You don’t want to vent the plastic. (laughing) Why would you want to do that? In fact, in some places in the country … up in Canada they’re starting to build crawl spaces that have … plastic goes all the way up the walls and completely sealed so absolutely no moisture gets in whatsoever. It’s a different type …
DAVID: That makes more sense to me.
TOM: Yeah, a different type of crawl space construction. But in an existing home like that, that would be the hot ticket, okay? So seal up those gaps and let’s get that space dried out and that, hopefully, is going to let your floor lie down nice and even. Okay, David?
TOM: Thanks very much for calling us at 888-MONEY-PIT.