Installing Rigid Foam Insulation In An Attic

When installing a foil faced foam board insulation.

Installing rigid foam insulation in an attic.

Use a chalk line or t square to mark where it needs to be cut. Once the attic is prepared then start to install the insulation. Cover the insulation with a vapor barrier before you install it. Seal the perimeter of each piece of rigid foam with caulk canned spray foam or high quality tape.

Mark the insulation where it lines up with the center of the rafter closest to the farthest edge. If there is any horizontal section of these joist bays that are exposed on one side to unconditioned space then the joist bays need to be insulated. Cut the insulation with a utility knife. Fasteners should be long enough to penetrate in to the rafter a minimum of inch.

Measure the space between rafters and cut the board to fit. Foam insulation boards can be attached to concrete walls as well and in such a case care should be taken not to chip the cement. A table saw will also cut the board but it. When installing the foam use caulk or tape for maximum insulation between the material and the board or floor.

For more information on the work i have described see two ways to insulate attic kneewalls. Fasten foam insulation boards to the interior of the rafters using screws or nails with 1 inch minimum washers or caps. How do you install rigid foam board. When installing foam insulation boards in the attic make sure you start from one corner and work your way around the room.

The superattic system utilizes proprietary silverglo rigid foam insulation panels to fully seal and insulate the attic directly beneath the roof rafters and directly inside the gable ends. Start at one corner of the attic and lay the piece of insulation lengthwise like a piece of drywall. Keep foam board insulation away from direct sunlight prior to installation. It will degrade its r value.

All foam boards absorb water vapor. The superattic system creates a continuous air and insulation barrier directly beneath the attic roof with no thermal bridging to compromise energy. When installing rigid insulation in an attic to be finished as a living space you must provide a route by which hot air.