Roof Insulation Vaulted Ceiling Unvented

If you want the attic to be conditioned space that is heated and cooled then your best bet would be an unvented cathedral ceiling sometimes referred to as a hot roof.

Roof insulation vaulted ceiling unvented.

An unvented assembly can perform well but it s important to get the details right to avoid sheathing rot. As with cathedral ceilings the insulation is in the rafters and or the roof deck. The quest for greater energy efficiency in buildings has led to increasing interest and need for insulation improvements in hvac equipment more airtight construction new materials and assemblies. Install insulation along the underside of the roof deck of an unvented attic rather than on the ceiling deck of a vented attic for either of two reasons.

The primary benefit of cathedralized attics is the ability to locate hvac ducts inside conditioned space where. Unvented attic assemblies code notes 2009 irc 2012 irc. Yes unvented roof assemblies can be insulated with fiberglass a wufi post and not just in climate zones 2b amp. 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.

Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction. How to avoid condensation leaks attic mold insulation mold structural damage to roof framing when roof venting is not possible cathedral roof and knee wall insulation venting air path options in older homes hot roof designs. To provide an unvented conditioned space for locating hvac equipment in the attic and or to provide a continuous thermal barrier for designs that have complex coffered ceiling planes and or numerous penetrations for lights speakers vents. Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense.

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. These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck. Martin s post focuses on the marketing of owens corning 039 s propink unvented attic insulation system. Verify that roof insulation installed under the roof sheathing is well supported.

You could leave the ceiling insulation in place providing some additional insulation for the living space below.