Can Icynene be applied directly to the underside of a roof without ventilation behind it?
Yes, Icynene is approved by the state to be directly applied to the underside of a roof. The reason for this is Icynene’s ability to form a complete air barrier and prevent airborne moisture from getting to the roof decking and condensing. More traditional types of insulation materials require soffit venting, ridge venting, and installation of “vent chutes” to carry air from the soffit to the ridge. With Icynene, this task and expense can be eliminated. Also, because there is no need to install vent chutes, the space that was previously occupied by the vent chute can now be used for the foam. This often means that a smaller rafter can be used, increasing headroom in many attic conversion type projects.
