Attic foil - does it really work?

I know radiant barrier works. Installed in my parents house and it has kept the upstairs cooler in the summer. It was installed when they had the roof replaced.

Family member has it in her roof, some sort of radiant barrier or foil or something. Anyway, phone reception blows bc of it. I barely get anything on my verizon phone. That's in Houston fwiw

You mean "faraday cage"

Not the jail in Jimmy Swaggart's hometown.

It works been using it on rental homes or flips since I tried it in 2001.

Good reduces heat

Bad does reduce life of shingles slightly but benefits offset the reduced life of your shingles.

DuPont and other companies does event make a weather barrier with radiant barrier to go behind the bricks. You need that gap for it to work. Does help reduce heat in a home and cost is not that much more.

How long does it take to damage shingles if it's a brand new roof?

What I'm hearing is it works but no one has any before or after numbers to prove it. My son has it. No rf interference but his attic temp is the same as mine. I don't have it. I'd have to see before and after elect. bills with no other changes before I get all froggy on this stuff.