The Benefits of Radiant Barriers

LESLIE: Now we’re going to go to Bill in Kansas.

Bill, how can we help you?

BILL: Got a question about a radiant barrier. I am building a new home; approximately 3,800 square feet and single story. And I have been told a lot of things, both pro and con, about radiant barriers – particularly the type that would go in the attic – and I kind of wanted your opinion on them.

TOM: Well, considering the part of the country you’re in and the very, very hot summers you get …

LESLIE: But they get very cold winters.

TOM: I know that. But still, with a very, very hot summer, I think the radiant barrier is when it does the most good. It’s going to do a good job of reflecting the UV back out of the house and not letting it build up. I think you will find that your attic will remain much cooler, if it’s properly installed. Since it’s a new house, the chances that you have to get it properly installed are probably better than if it was an older house because a lot of times you find radiant barriers put in very badly in an older house. But if it’s properly put in, it doesn’t really add up a lot of extra cost. I think it’s probably a good thing to do.

But Bill, the really important thing for you to pay attention to when you construct this roof in that newer house is the roofing ventilation system. That is as important as the barrier. And you want to make sure that you have plenty of ventilation. I recommend a ridge vent down the peak of the roof and a soffit vent all along the sides, because those two systems together are going to work together to always constantly flush hot air out of that attic and then will also take out moist air in the winter, which makes it hard for the insulation to work.

BILL: OK, sounds good. I have one other question.

TOM: Sure, go ahead.

BILL: Do side walls or the floor of the home need to be covered by a radiant barrier?

TOM: Do side walls or the floor. I would say no: the floor, certainly not because it needs to be up high near the roof; the side walls, I don’t see a big benefit there. I think I would just put it at the roof line.

BILL: OK. I do appreciate all that. You would not even consider a strong west exposure, then, on a side wall.

TOM: No, because the other issue is what’s the siding going to be. It’s going to be vinyl siding?

BILL: It’s going to be brick but …

TOM: If it was vinyl, I think potentially you could overheat that vinyl and have it be all melt-y and warpy-looking.

BILL: Thank you for your thoughts.

TOM: You’re welcome, Bill. Thanks so much for calling us at 1-888-MONEY-PIT, 888-666-3974.

We have the smartest callers on this show, It’s great.

LESLIE: Well, you’re just a bucket of information.

TOM: Well, you know, I’ve got no life so that’s all I do is study this stuff. (both chuckle) But thanks for the compliment.

LESLIE: But that’s great. That’s why it’s so helpful for our callers.

TOM: Thanks for the compliment. I think. I think.

LESLIE: You’re welcome.