Putting 1 Foil Faced Ridig Board Under Attic Roof

If you want to use them without creating a vapor barrier look for permeable iso panels faced with fiberglass.

Putting 1 foil faced ridig board under attic roof.

However foil faced iso panels are warranted as impermeable. 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. Foam insulation boards are the best material with which to work when undertaking a do it yourself project because foam. Foil insulation is a radiant barrier and it works by.

The r value of the insulation must meet local building code requirements for unvented attics to prevent condensation. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. 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. 2 measure and cut the foam boards as.

Multiple layers of foam board may be required. Installing foam insulation boards in the attic is no that hard and can save you money compared with professional installation. I have 2x10 rafters. Installing rigid foam insulation.

Install ap foil faced foam boards between rafters directly against the bottom of the roof sheathing. There s two ways you can go about with foam board insulation. 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. Polyiso comes in several thicknesses and is used over house sheathing underneath siding or in attic spaces where its reflective properties are very effective.

My plan was to rip one inch strips of wood to put on the back of the roof decking then cut the polyiso board to fit in between the rafters leaving one inch gap for ventilation as well as a 1 4 inch gap on either side to seal after installation. This is an even more dense and more expensive foam board insulation. 4 of polyiso under 4 of eps all above the original roof sheathing. Foam board insulation in the attic can cut down on energy costs and simultaneously promote a more environmentally sound way of daily living.

Then a second layer of plywood sheathing and asphalt shingles following the steps explained in this article. Cut ap foil faced foam sheathing to fit snuggly between the rafters.