Why DensDeck® Prime Roof Boards?
The patented DensDeck® design employs glass mat facings front and back that are embedded into a water resistant and moisture resistant treated gypsum core, providing excellent fire resistance, moisture resistance, and wind uplift properties. The unique construction of DensDeck® Prime Roof Boards provides excellent flute spanning and will help stiffen and stabilize the roof deck. Additionally, DensDeck® Prime has been shown to withstand de-lamination, deterioration, warping, and jobsite damage more effectively than roofing membrane substrates such as paper-faced gypsum board, fiberboard, and perlite insulation.
Roof system manufacturers and designers have found DensDeck® Prime Roof Board to be compatible with many types of roofing systems, including:
- Modified asphalt
- Single ply
- Metal systems
- Re-cover board
It can also be used as an overlayment for polyisocyanurate and polystyrene insulation. DensDeck® Prime can also be used as a form board for poured gypsum concrete deck in roof applications as well as a substrate for spray foam roofing systems. 1/2" and 5/8" DensDeck® Prime may also be used in vertical applications as a backer board or liner for the roof side of parapet walls.
DensDeck® Prime allows the bonding of cold mastic modified bitumen and torching directly to the surface. Refer to specific membrane system application instructions. System manufacturers and designers have found DensDeck® Prime to be compatible with bonding adhesives for fully-adhered single-ply membrane applications and has been shown to extend the adhesive usage.
DensDeck® Prime Roof Board's exceptional moisture resistance and low R-value make it the preferred substrate for vapor retarders. An excellent fire barrier, it features a noncombustible core and inorganic surface that offers greater fire protection than other conventional commercial roofing products when applied over combustible roof decks and steel decks. DensDeck® Prime is FM tested and approved as the only 1/2' gypsum product to meet the calorimeter requirements for conventionally insulated decks. Tested in accordance with ASTM E84, its surface- burning characteristics are Flame Spread-0 and Smoke Developed-0. 5/8" DensDeck® Prime can replace any generic type X gypsum board in any roof assembly in the UL Fire Resistance Directory under the prefix “P.”
G-P Gypsum Corporation
133 Peachtree Street, N.E.
Atlanta, GA 30303
Technical 1-800-225-6119 (8-7 ET)