ThermaCal® 1 Specs

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      Why ThermaCal® 1?

      Perfect for structures with cathedral ceilings, glue lam, post & beam construction and conditioned attic spaces, they help insulate against heat drive into the living space/conditioned space under the roof while serving as a nailable base. In addition, they exhaust excess moisture before it can condense in the deck or roofing system. These panels can be installed on top of structural wood or steel sloped roof decks (Contact GAF for other acceptable decks).


      Reduced Heat Loss

      Exclusive tongue-and-groove design minimizes heat loss up through the panel joints

      Fully-Machined Panel

      Pre-spaced sheathing eliminates the need for H-clips and allows for sheathing expansion

      Exceptional Airflow

      Unique spacer pattern maximizes airflow ("upventing") and reduces hot spots
      • Panel Configuration:  Single-layer of sheathing, air space and polyiso foam insulation.
      • Sheathing Options:  7/16" (11.1 mm) OSB nailing surface (standard); optional 5/8" (15.9 mm) and 3/4" (19.1 mm) OSB or plywood.  Fire-treated options also available.  Contact GAF for additional information.
      • Solid Wood Spacer Blocks:  Positioned 12" (305 mm) or less apart in all directions minimizes the chance of deflection or nail back-out.
      • Optional Air Space and Polyiso Thicknesses Available:  Contact GAF for additional Information.

      Where to buy

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