I am building a new house that will have cement barrel tile on the roof. Should I use a foil backed decking or is it needed with that type of roof?
Tom: Yes, yes, and yes with all roofs, even a metal roof that has some emissivity properties, low emissivity, still the radiant barrier is what you want. A radiant barrier is a radiant barrier, a roof is a roof, insulation is insulation, everything has its place and its purpose and the radiant barrier has a very important one here.
Charlie: Hold on, okay, so that’s a foil-backed decking.
Tom: That’s a radiant barrier.
Charlie: Right, but he’s not talking about … You’re not saying the foil on top, I just want to make that clear.
Tom: No, no. It’s used as a radiant barrier, the foil faces the attic.
Charlie: Okay, because there seems to be this move, again, I see houses going in where they’re putting this foil on the roof and putting the shingles on top of it.
Tom: That’s blind ignorance in the industry and what those are is it is a radiant barrier, they’re putting it and using it as an underlayment. When it becomes an underlayment and you put the roof on it, it no longer acts as a radiant barrier, just an underlayment, and if you read the specs on that and nobody seems to understand that somebody spends a lot of money writing these specifications, putting these booklets together, nobody reads them, and then you get a bunch of propaganda out there and then all of a sudden you’re a genius. Sad.