DensDeck Prime Roof Board is built to stand strong with EONIC™ Technology for enhanced moisture resistance and increased membrane bond strength.

Fire Resistance

Non-Combustible Gypsum Core

  • 0 flame and smoke spread when tested in accordance with ASTM E84 and CAN/ULC-S102.
  • UL Classified for resistance to external fire sources [per ANSI/UL 790 and CAN/ULC-S114].
  • UL Classified for resistance to fires below roof [per ANSI/UL 1256].

Wind Resistance

Board Strength and Mat to Core Bond

  • Improves roof’s ability to resist wind.
  • Increases membrane bond strength compared to paper-faced insulation or no coverboard.
  • Improves fastener pull through performance compared to paper-faced insulation or no coverboard.

Puncture Resistance

Rigid Board Protection for Membrane and Insulation

  • Resists impact from repeated events such as maintenance foot traffic.
  • Helps relieve static pressure caused by the weight of rooftop equipment.
  • Helps defend against dynamic impact from flying debris.

Hail Resistance

Strength of gypsum core with fiberglass mat reinforcement

  • Stands strong against repeated hail strikes.
  • DensDeck® Prime roof boards are included in more FM (VSH) approved multi-ply assemblies than any other coverboard.¹

*Please consult ASTM E136 and ASTM E84 for information concerning the test methods and measures for combustibility and flame spread. For information concerning the UL 790 and UL 1256 classifications for DensDeck® Roof Boards, consult the applicable UL certifications directory.  Please note, however, that the performance of a roof depends on all components used in the roofing assembly and how the components interact.  Passing a fire test in a controlled laboratory setting does not mean that a particular product or system will necessarily provide the same resistance or protection in an actual fire.

¹Consult RoofNav for FM-approved and VSH assemblies with DensDeck® prime and DensDeck® StormX™ Prime Roof Boards.

Moisture Resistance

+ Control Moisture with Eonic™ Technology

With the addition of EONIC™ Technology, a patent-protected enhancement, DensDeck Prime Roof Board has double the resistance to moisture to defend your roof and better protect the contents inside your structure with the following benefits:

  • 5% total water absorption resistance by weight
  • 1-gram nominal surface water absorption performance on both sides of the board


Data That Speaks to Durability

When exposed to water all roof boards lose strength, including flexural strength, but to varying degrees. In third-party test results of 1/2″ roof boards.*

  • DensDeck® Prime Roof Board with EONIC™ Technology tested 52% stronger than gypsum fiber and 57% stronger than alternative coated glass mat when dry
  • After a standard 2-hour soak, DensDeck Prime boards tested 267% stronger than gypsum fiber and 87% stronger than alternative coated glass mat
  • DensDeck Prime boards tested stronger after the 2-hour soak than both gypsum fiber and alternative coated glass mat tested before exposure to moisture

*Third-party testing of 1/2” boards conducted by Trinity ERD in Columbia, South Carolina in October 2016 and December 2017. Testing conducted in accordance to ASTM C473 to meet ASTM C1177.

In third-party test results comparing ½” DensDeck® Prime Roof Board to other roof board materials.**

  • DensDeck Prime boards tested 74% stronger on the face and 14% on the back versus gypsum fiber
  • DensDeck Prime boards tested 2.5x stronger on the face and 7x stronger on the back versus alternative coated glass mat

**Testing of ½” boards conducted by PRI Construction Materials Technologies in October 2017 and in accordance to ASTM C209

In third-party test results of ½” DensDeck® Prime Roof Board versus other materials***.

  • Alternative coated glass mat gypsum absorbed 76% more water
  • Gypsum fiber absorbed 132% more water

NOTE: Moisture has a detrimental effect on every cover board, including DensDeck® Roof Boards and every effort should be taken to keep them dry before, during and after installation. Damage or reduction in performance resulting from exposure to more than an incidental amount of moisture is NOT covered by the limited warranty for DensDeck® Roof Boards. For additional information on installation guidelines and product warranty, please see Resources.
***Testing conducted by PRI Construction Materials Technologies in October 2017 and in accordance to ASTM C473. ½” boards tested for DensDeck® Prime Roof Boards, gypsum fiber and alternative coated glass-mat gypsum roof boards.


Get all the detailed technical information you need to know about DensDeck® Prime Roof Board. You can explore the limited warranty, submittal and the 3-part spec.

DensDeck Prime Roof Board Limited Warranty

DensDeck Prime Roof Board Submittal

DensDeck Prime Roof Board 3-Part spec

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