Spray Foam Insulation Attic Floor

The best part of using foam it green spray foam on an attic floor is you only need 1 inch cured thickness to seal the living spaces you use from the attic.

Spray foam insulation attic floor. This spray foam is applied as a low or high pressure two component polyurethane spray foam that can be applied onto walls in unvented attics to ducts and ceilings and in vented attics and crawl spaces. Install a minimum of 1 inch of spray foam insulation over the attic floor to provide a continuous air control layer. That gives you the chance to maximize your energy bill savings while spending the least on the project. If you leave the insulation in the attic floor after insulating the roofline the attic will be cooler in winter than if you remove the insulation.

But a common reason to put spray foam on the roofline is to avoid having to air seal the attic floor. Hire a pro to install spray foam insulation. There is no need to install any spray foam on your attic floor since you will be moving your air barrier and your insulation layer to the sloped roof assembly. You can use rigid foam panels or do as tom silva does with nearly all houses these days.

So here s the followup article i promised. The building envelope should completely surround the conditioned space and the insulation needs to be in contact with the air barrier. Spray foam comes in two flavors open cell and closed cell and provides both parts of the building envelope the insulation and the air barrier. If you re considering turning your attic into conditioned storage or living space it s worth changing tactics to insulate between the rafters and wall joists instead of the floor.

We placed data loggers near the ridge and floor of the attic as well as in the living space and outdoors. The most important reason to transform your vented unconditioned attic into an unvented conditioned attic is to bring your air handler and ductwork inside your home s conditioned space. When we seal the attic with spray foam it s as tight as a butter tub. However in a traditionally insulated attic insulation on the ceiling the attic is vented.

An open cell foam low density spray polyurethane is a spray applied to provide continuous insulation and an air sealing barrier. Thus the air in the attic is connected with the air in the house. Then you can use other forms of insulation like fiberglass or cellulose to add r value now that you have a tight air seal. In that last article i showed the dew point data for the four locations and said i d come back with more explanation.