Every roof will face real-world stress like wind uplift, hail, fire, snow, foot traffic and prolonged moisture exposure. Designing for these conditions starts with the right assembly. To help safeguard against challenges, specify DEXcell^® Roof Board products as a key component in your roof assembly systems. A hard coverboard enhances durability, energy efficiency and moisture management – adding mechanical strength, thermal performance and protection in a single layer.

Whether you are designing data centers, hospitals, schools, warehouses or distribution centers, your roof assemblies protect precious lives and expensive equipment. Long-term performance and resilience start with smart material choices, like DEXcell.

What it does: By protecting the insulation below and the waterproofing above, a hard roof coverboard provides a durable, stable foundation for the roof assembly.

What it doesn't do: DEXcell products do not expand or contract, or vary in thickness, ensuring dimensional stability and long-term reliability within the roof assembly.

Testing and third-party approvals

Here are six key standards and material classifications that govern commercial roof assemblies and third-party approvals:

1. FM 4450 (Wind uplift resistance in insulated roofs). This testing protocol is designed to replicate real-world wind conditions and is often a minimum requirement in wind-prone regions or on Factory Mutual insured buildings.
2. FM 4470 (Very severe hail, fire and impact testing). Expanding on FM 4450, roofing assemblies seeking FM 4470 VSH classification often require a high-compressive-strength coverboard.
3. ASTM C473 (Physical properties of gypsum boards). This classification measures key physical properties, including flexural strength, core and edge hardness, and water absorption. A gypsum-based coverboard that meets ASTM C473 criteria is proven to resist warping, cracking and surface damage.
4. UL 790 (Fire resistance of roof assemblies). Including a non-combustible coverboard in your roof assembly can help achieve a UL Class A fire rating – required by many jurisdictions for commercial buildings. It can also help reduce fire spread internally.
5. ASTM C1177 (Performance for glass mat-faced gypsum substrates). Coverboards that meet C1177 can resist mold and moisture, which is especially important during construction delays and exposure to inclement weather.
6. ASTM C1325 (Cementitious panels for exterior systems). Crucial to non-structural cement-based panels used in building envelopes, cement coverboards are ideal for projects with frequent foot traffic (like maintenance workers) or exposure to high moisture.

To learn more, read the NGConnects™ Blog post: Six key standards in low-slope roofing – and why they matter. For product recommendations, contact me.

DEXcell: Four product options, one complete roofing solution

• DEXcell® Glass Mat Roof Board: A substrate board, thermal barrier and/or coverboard for most commercial roofing applications.
  

• DEXcell FA® Glass Mat Roof Board: Designed for fully adhered roof systems, providing increased fire performance and acoustical benefits.

• DEXcell FA VSH® Glass Mat Roof Board: Engineered for extreme conditions, with a Very Severe Hail (VSH) rating and enhanced hail, puncture and wind resistance.

• DEXcell® Cement Roof Board: Features an exceptionally hard, durable surface to withstand prolonged moisture exposure.

To support your specification process, reference our DEXcell selection chart: “Choose the Best DEXcell Product for Your Project.”

Trusted and approved by major commercial roofing manufacturers

DEXcell Roof Board products are tested, vetted and approved for inclusion in leading roofing manufacturers’ systems.