Foil insulation is a radiant barrier and it works by.
Putting 1 foil faced ridig board under attic roof.
2 measure and cut the foam boards as.
The r value of the insulation must meet local building code requirements for unvented attics to prevent condensation.
If you want to use them without creating a vapor barrier look for permeable iso panels faced with fiberglass.
Installing rigid foam insulation.
There s two ways you can go about with foam board insulation.
Then a second layer of plywood sheathing and asphalt shingles following the steps explained in this article.
Install ap foil faced foam boards between rafters directly against the bottom of the roof sheathing.
Select rigid foam insulation boards that are at least 1 2 inch less in thickness than the rafter space is deep if you plan to finish the attic as living space.
Multiple layers of foam board may be required.
Foam board insulation in the attic can cut down on energy costs and simultaneously promote a more environmentally sound way of daily living.
However foil faced iso panels are warranted as impermeable.
We live in zone 5 suburb of chicago and are hopefully about to put rigid foam above the roof sheathing on just the northeast roof portion of our roof.
Foil insulation underlayment is recommended under a metal roof and in most cases the shiny side should be facing up but there s a catch.
Installing foam insulation boards in the attic is no that hard and can save you money compared with professional installation.