Are Radiant Barriers Cost-Effective?
LESLIE: Alright. Now we’ve got Larry from Arkansas on the line with a heating-and-cooling question. Welcome, Larry.
LARRY: I want your opinion on the radiant barriers for insulating the attic or the roof. The two questions that I have is it comes in rolls that are either placed on the attic floor or stapled to the roof rafters. And the other is a flexible material that is held in place by spring action between the roof rafters. That comes in 2×4-foot sections that can just be bowed and placed – and set it place and a spring action holds them there.
TOM: So, it’s a good question, Larry. We hear a lot of folks ask about radiant barriers and I personally am just not convinced that there’s a cost-benefit analysis out there that favors installation of these things. They’re not inexpensive; they do cost some dollars. And I do have a couple of concerns.
One of which is that when you trap the heat just on the opposite side of the roof sheathing and then attempt to sort of radiate it back up through the roof sheathing again, obviously it’s passing through the shingles twice and that’s going to accelerate the deterioration of the roof shingles. Because the more heat that gets through those shingles, the shorter the roof life.
I think that if you’re trying to save money in your home, I would concentrate on two things. Number one, I would concentrate on the amount of insulation, because most folks don’t have enough. In an area like Arkansas, you’re probably looking at somewhere between 19 to 22 inches of fiberglass-batt insulation or 22 inches of even blown-in insulation.
The second thing I would concentrate on is attic ventilation, which I have rarely, rarely, rarely seen a house that really has enough of this, because the standards don’t require what I would consider enough. What I would have, if it was my home, is a continuous ridge vent going down the peak and then fully-opened soffit vents on the ends of the building. Because that’s going to allow air to get into the soffits, right up under that roof sheathing, take the heat out with it in the summertime, take the moisture out with it in the wintertime and exit at the ridge vent.
And I think those two things are the smartest energy-saving home improvements that you can make. And I would put those way in front of any consideration whatsoever for radiant barriers. I’m just not convinced there’s enough data on them to say that they make a cost-effective improvement to your home.
LARRY: Our air-conditioning bills in the summertime are still over $225 a month and …
TOM: Wow. Right now, you’re spending $220 a month on air conditioning in the hottest months of the year. So, if you cut that in half – let’s say you spend $110 a month – it would still take you 2½ to 3 years to pay that off. But I don’t think you can cut it in half. I think you may cut it a little bit but I think the payoff’s going to be so long it’s not going to make sense.
Alright? That’s my two cents on it. Hope that helps you out. Thanks so much for calling us at 888-MONEY-PIT.