How to Insulate Underneath a House
LESLIE: Carol in California is on the line with an insulation question. How can we help you today?
CAROL: I have an old house. It sits high off the ground and it’s one of the houses that when they dismantled the camps, they took houses out and people bought them and set them up. And it’s all open underneath and it is freezing cold in the winter and very hot in the summer. Is there something that I can do underneath the house?
TOM: So there’s no insulation?
CAROL: I don’t think so. Very little, if any.
TOM: Yeah. Are there – is it like a sort of open floor joist? Like do you see the floor joists when you look under and up?
CAROL: You know what? I haven’t been under the house.
TOM: Yeah. Well, look, you’ve got to get somebody under there, Carol, to see what the structure is. But we have the technology, OK?
TOM: You know, if it’s a standard floor-joist construction, you can add insulation in between the floor joists and then under that, you could use 2-inch insulating foam board and then nail that to the bottom of the floor. And that would seal up the floor from the cold air that’s getting up in there.
And I would also take a look at the attic to make sure that that’s insulated. And you just may have a house that needs a few very basic, energy-saving improvements to it.