Performance Data for DensDeck® Prime and DensDeck® StormX™ Prime Roof Boards

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

To varying degrees, exposure to freeze/thaw cycles have a compromising effect on the vertical pull strength of all roof boards, producing cracks and ruptures that continue to grow with time and lead to delamination. In vertical pull strength testing of 1/2″ roof board materials after exposure to 21 freeze/thaw cycles:

• DensDeck^® Prime Roof Board was 2x stronger on the face and 1.3x stronger on the back versus gypsum fiber
• DensDeck Prime Roof Board was 12x stronger on the face and 24x stronger on the back versus alternative coated glass mat

*Third-party testing conducted by PRI Construction Materials Technologies LLC in Tampa, FL, concluding in May 2018. Test conducted in accordance to a modified form of ASTM C67 as well as ASTM C209.

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

• Gypsum fiber absorbed 2.3x more water
• Alternative coated glass mat gypsum absorbed 4x more water

*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.

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.

Enhancing the durability and puncture resistance of the DensDeck^® Roof Board offerings for FM Global Very Severe Hail (VSH) rating specifications, DensDeck^® StormX™ Prime Roof Board meets these rigid standards for impact resistance, using engineering ingenuity to help reduce roof assembly storm damage risk.

FM Global tests roof systems for moderate and severe hail impact resistance on how the withstand dropping a 2-inch diameter 1.19-pound steel ball from either 81 inches or 141.5 inches, respectively. This results in impact energies of 8 ft-lbs for moderate hail (1.75″ or bigger) and 14 ft-lbs for severe hail (2″ or bigger). The new VSH designation uses an ice launcher to propel a 2-inch diameter laboratory-made ice ball at 152 to 160 feet per second. This applies impact energy of 53 to 58 foot-pounds on the surface of the tested sample–an increase of almost 4x compared to severe hail. Learn more about FM’s VSH impact-resistance classification here.