Spray Foam Insulation Under Metal Roof Without Air Space Good

For best protection professional contractors recommend at least 6 inches of foam insulation board.

Spray foam insulation under metal roof without air space good.

The biggest benefit of spray foam insulation is its air sealing quality so if air is infiltrating into a spray foam attic then the installers missed some spots and need to go back and make it right. In the knee wall area the insulation is in the floor and on the. What s not guaranteed however is that all spray foam homes will be efficient and comfortable. To get the best performance out of spray foam insulation you must cover the roof rafters and surrounding areas as thoroughly as possible.

Even small gaps can allow the passage of warm air through the foam rendering the foam all but useless as an insulator. The building envelope should completely surround the conditioned space and the insulation needs to be in contact with the air barrier. A roof breathes without spray on foam insulation to some extent and it also allows you to see where any dampness is coming in and repair it in this area. Since spray foam is both insulation and air barrier proper alignment of insulation and air barrier is guaranteed.

Nail 1 furring along every rafter side against the roof deck. They are not susceptible to moisture infiltration and will keep the roof dry even without a good ventilation system. You take a shower but forget to turn the bath fan on. Other products that say they repair roofs we have seen a product called stormflex that s says it does a better job at repairing tiles etc than spray on foam.

An unvented attic air sealed with spray foam insulation limits outdoor air entry and as a result indoor combustion air should not be considered available for fuel fired combustion appliances located within the attic space.