Using Styrofoam For Attic Roof Insulation

You can use a foamboard adhesive to glue it in place.

Using styrofoam for attic roof insulation.

Polyiso comes in several thicknesses and is used over house sheathing underneath siding or in attic spaces where its reflective properties are very effective. If you plan on finishing your attic then you cannot install it directly. I just insulated my attic this weekend with blown in cellulose insulation and achieved between r 30 to r 45 for about 0 42 sq. Use furring strips nailed into the sides of the rafters so that you have something to fasten the board to.

2 measure and cut the foam boards as. The superattic system creates a continuous air and insulation barrier directly beneath the attic roof with no thermal bridging to compromise energy performance. Do not nail the board into the roof. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away.

This is an even more dense and more expensive foam board insulation. One common use of extruded polystyrene foam board is for foundation insulation panels. As we have discussed previously spray foam insulation can effectively seal roofs and other spaces where condensation is more likely such as an attic. I used 20 bags which is the minimum purchase for a free 24 hour blower rental at both hd and lowes.

The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. As with attic floor insulation moisture and heat removal are the reasons for creating proper air. 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. For the same reason insulation shouldn t touch the roof s underside.

Using spray foam insulation in an unvented attic application both low density open cell and medium density closed cell spray foam can be used in an unvented attic to provide the needed thermal resistance and airtightness. These insulation materials are not only used to insulate home to bar air from coming in and out but to also protect the space from elements such as mold rodents moisture and dust. 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. It provides an r value of 6 per inch of thickness and often comes foil faced to help reflect radiant heat.

The styrofoam insulation that home depot carries is only rated for r 5 per inch. Baffles establish a channel for air to circulate between the insulation and the roof sheathing. Your board must leave at least inch gap between the board and the roof.