Roof Board

DEXcell® Cement Roof Board

A lightweight, moisture- and mold-resistant panel that provides an exceptionally hard, durable surface that withstands prolonged exposure to moisture.


3-Part Guide Specs




Withstands prolonged exposure to moisture

Use for a wide variety of roofing systems
  • Ideal for all roof systems.
  • Excellent bond/pull through.
  • Improved moisture resistance.
  • FM Class 1/UL Class A fire-rated.

DEXcell® Cement Roof Board is a lightweight, moisture- and mold-resistant panel that provides an exceptionally hard, durable surface that withstands prolonged exposure to moisture. Its composition of Portland cement and lightweight aggregate with heavy-duty fiberglass-mesh facers makes it an excellent fire and thermal barrier. This moisture- and mold-resistant cement panel is a substrate board, thermal barrier, and coverboard for commercial roofing applications.

Use it for a wide variety of roofing systems, including fully adhered, mechanically attached, and ballasted roofs using single-ply membranes, modified bitumen, fluid-applied, built-up roofing, spray foam, and metal.

DEXcell Cement Roof Board is one of four products offered by DEXcell Roof Boards.


  • Use it as a coverboard in roofing assemblies. DEXcell Cement Roof Board protects and supports the roof membrane; provides increased fire, moisture, and mold resistance; and reduces the potential for penetration damage to the membrane.
  • Use it to sheathe the roof side of parapet and penthouse walls. Ideal for green roofs and photovoltaic systems.


  • Excellent bond/pull-through/uplift values.
  • Impact-resistant, extremely durable, and dimensionally stable.
  • High compressive strength.
  • Lightweight, cementitious core.
  • Superior moisture resistance.
  • Exceptional freeze/thaw resistance.
  • Scores and snaps easily.
  • Meets ASTM C1325.
  • Meets UL Class 1 and UL Class A fire ratings for roofing systems up to unlimited slope per UL 790 and ULC CAN-S107.
  • Use in accordance with a rated system, and DEXcell® Cement Roof Board provides a thermal barrier meeting IBC Section 2603.
  • Resists the growth of mold per ASTM D3273 with a score of 10, the best possible score.
  • DEXcell Roof Board Limited Warranty.

Video: Discover the Versatility of DEXcell Cement Roof Board



Products that suit any project criteria

Product Details


Roof Deck




7/16", 5/8"



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National Gypsum Company is the exclusive service provider for products manufactured by PermaBASE Building Products, LLC.