Unvented Cathedral Ceiling Insulation

Suggestions for un vented or hard to vent building roof cavities.

Unvented cathedral ceiling insulation. If installed properly it will create an effective air and vapor barrier to keep interior moisture away from the roof sheathing where it can condense and cause problems. Worries about the hot roof un vented cathedral ceiling designs how to. Air permeable insulation such as fiberglass batts dense packed cellulose or blown in fiberglass can t be used alone for an unvented assembly since these types of insulation can allow moist indoor air to reach the cold roof sheathing leading to condensation or moisture accumulation.

Martin s post focuses on the marketing of owens corning 039 s propink unvented attic insulation system. Our summers in northern california can be pretty hot amp i am looking to add more insulation to my attic the attic floor is insulated already there is a ridge vent there are 2 gable vents 1 has a fan there are 2 between rafter vents. Regarding the roof insulation closed cell foam is the best product to use for an unvented cathedral ceiling.

An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. Yes unvented roof assemblies can be insulated with fiberglass a wufi post and not just in climate zones 2b amp.