Spray Foam Insulation Thickness Attic

There can be a significant difference between the thickness of what your spray foam insulation requires to provide protection compared to what your local building codes mandate.

Spray foam insulation thickness attic.

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. Synergy insulation is an industry leader in attic insulation and spray foam roofing. A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents. Insulstar spray foam insulation is a spray applied semi rigid cellular polyurethane foam plastic insulation having a maximum thickness of 2 inches and a nominal density of 2 0 pcf.

Only spray polyurethane foam can be used for this application as batt insulation will end up sagging and blown insulation simply can t adhere to the roof decking. One of the key differentiators between traditional insulation materials and spray foam insulation is the latter s ability to insulate and air seal. Then you can use other forms of insulation like fiberglass or cellulose to add r value now that you have a tight air seal. Spray foam insulation still is considered the most economical method to attain the air tightness requirement of 3 5 ach and lowest eri.

This application effectively seals off the attic from the outdoors and eliminates air leakage and infiltration through the attic and roof areas. The icc es report for insulstar spray foam from ncfi esr 1615 issued february 1 2005 lists a maximum thickness of only 2 inches. Choose foam it green spray foam insulation kits and don t settle for less than you deserve. Spray foam expands after it is applied allowing even the smallest cracks and crevices to be covered and well insulated.

Foam insulation as an air sealing material. So if the ideal r value for your home is r 40 your contractor may only need to spray five inches of foam insulation. Nothing unusual about that. Foam insulation provides an air barrier to wherever it is applied to help mitigate air leakage from the building.

Spray foam insulation offers the highest r value in insulation. Spray foam kits are quicker and easier to use plus you get a seamless air barrier and high r value in just 1 inch. Earlier this year i got a question about a home that had spray foam insulation in the attic. This is compared to having to stack fiberglass as high as 14 16 inches to get the same results.