Learn how to warm up a cold floor. Find out how insulating the floor joists in your crawlspace and installing radiant heating can help warm up a cold floor.
LESLIE: Next up, Dean in North Dakota. What can we do for you?
DEAN: My house has cold floors. We built a brand new rambler three years ago. We have no basement but we have a crawlspace  and there is heat in it. But nevertheless, the floors are just always cold. They’re laminate and no carpet. And I was wondering if it would be beneficial to insulate the floor joists ?
LESLIE: Is it possible to insulate with the heated space below, Tom?
TOM: You know, it is possible.
LESLIE: What about moisture?
TOM: I wouldn’t be too concerned about moisture. But you have a laminate floor  right now?
DEAN: Yes and I – from what I understand, there is a vapor barrier under the laminate.
TOM: The way to handle this, Dean, is to basically put unfaced fiberglass insulation in the beams in the crawlspace. So you’re going to go in the crawlspace and, working upside, you’re going to place unfaced bats  in between the floor joists of the floor structure.
LESLIE: If they’re unfaced, Tom, do we need those insulation straps that sort of staple in to the joists?
TOM: Yeah, you know – right. There’s a couple of different ways to strap it but what you could do is you could use those wire insulation hangers that basically are just a little bit longer than the space between two floor joists. And that basically springs in (ph) and supports it in place.
The bats itself are usually about eight feet long and you would buy them either for floor joists that are 16 inches on center or 24 inches on center. And that’s going to really do a good job of warming up that floor.
DEAN: How thick of an insulation would you recommend?
TOM: I would use as much insulation as you have floor space. So for example, if the floors are eight inches or ten inches, I would use eight inch thick or 10 inch thick bats.
LESLIE: So go to the bottom of that joist.
TOM: Absolutely. You can’t really put too much in there and the additional cost is minimal compared to the value, again, of really making that floor warm. And I’ve got to tell you, your tootsies will really appreciate it, Dean.
DEAN: That’s good to know.
TOM: Dean, thanks so much for calling us at 1-888-MONEY-PIT.