Rigid Insulation At Unvented Roof

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Rigid insulation at unvented roof. Ratio of r value between rigid insulation and batt insulation is climate dependent. We agree that avoiding sheathing rot is critical and that air permeable insulation such as fiberglass or cellulose cannot be used alone. Foam free don t stay stuck in the sci finightmare of foam foam foam. Houston tx is located in a hot humid climate region.

If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies. 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. This section outlines the conditions for unvented attic roof assemblies. In the most recent issue of fine homebuilding martin holladay wrote a piece on insulating unvented roof assemblies.

Rigid insulation used to control condensing surface temperatures rigid insulation installed above roof deck. Note that table r806 4 indicates the amount of insulation above the roof deck or air impermeable insulation below the roof deck required for condensation control assuming minimum required total insulation as indicated in section n1102 building thermal envelope. Figure 3 shows the potential for condensation of an unvented roof assembly in houston tx.