Insulation Entirely Above Roof Deck

Ashrae 90 1 defines a roof with insulation entirely above deck as a roof with all insulation 1 installed above outside of the roof structure and 2 continuous i e uninterrupted by framing members table 1 compares prescriptive requirements of the 2004 and 2007 editions of ashrae 90 1.

Insulation entirely above roof deck.

Placing all of the iecc code required insulation above the roof deck with a vapor retarder will provide acceptable hygrothermal performance in all climate zones figure 7. Generally more insulation is needed for condensation control in colder climates. 2007 levels are based on today s energy. This meets the requirements of section 5 1 4.

Insulation entirely above the roof deck. Roofing with insulation entirely above deck a roof with all insulation 1 installed above outside of the roof structure and 2 continuous i e uninterrupted by framing members.