LESLIE: Alright. Now I’ve got James in Florida on the line who has got a question about insulation. How can we help you?
JAMES: OK. I have a house with a 4-inch layer of insulation: the fiberglass insulation. And I’m wondering if I can put down a layer of the sheeting that’s called radiant barrier?
TOM: Yeah. I don’t think that it’s a good idea for you to use a radiant barrier. I think the jury is still out on whether or not it’s going to work. I think if you’ve only got 4 inches of insulation, the single most effective thing that you could do is to add more insulation there.
JAMES: I see.
TOM: It depends on how much room you have there. Most homes need 19 to 22 inches. If you’ve got a low attic space and you can only get in 12, then you take what you can get. But if you can get more insulation in there, that’s going to make a big difference to you. And make sure you also add additional ventilation to the roof space, because that’s going to let any moist air out that collects in there in the cooler seasons.
JAMES: Sure. Thank you very much.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.
I had a roofer tell me that radiant barrier installed under the roof will “cook” the shingles. I don’t see how and I just looked up the RIMA site. What is your answer?
Roy, I think there are many more effective ways to increase your home’s efficiency other than radiant barrier. It does seem to allow the roof to get hotter, and may lead to a shorter roof life but I’d suggest you focus on having ample insulation first.