Saturday, July 10, 2010
Insulating our way to Net-Zero: Icynene
Another integral part of creating a well sealed and insulated space involved the use of Icynene spray foam insulation. Icynene is a 100% water-blown insulation that sprays on as a liquid and immediately expands to 100 times its volume in soft foam that fills every crack and crevice while providing a flexible seal and a R-3.7 insulation value. It does not out-gas or emit any harmful fumes and it retains a stable R-value across time. It is an open cell foam, so it does not block the movement of water vapor. Icynene is a petroleum-based product (Icynene-R is a new product based on castor oil)that is a flame retarding material that will be consumed by flame, but contributes no fuel and will not sustain fire upon removal of the flame source. It must be covered by an approved thermal barrier, which our builder will accomplish by seperating it from living space with drywall.
More expensive than wet-spray cellulose, but less expensive than closed cell spray foam, our builder chose to selectively use it in hard to access or otherwise challenging areas, like the vaulted ceiling, where it clings tightly in place, helping form a continuous, insulating air barrier. Seven inches were sprayed along the roofline, for an R-25 insulation rating. EarthCraft specs say R-20 Icynene is equal to R-30 of fiberglass or cellulose on vaulted surfaces.