DensDeck StormX Prime Roof Board

DensDeck StormX Prime Roof Board

Product Descriptive Name
Enhanced Coated Glass Mat Faced Gypsum Cover Board 
Product Short Description
DensDeck StormX Prime Roof Board contains an enhanced coated glass mat facer and achieves FM's VSH approval in select JM TPO systems.

Product Details

DensDeck StormX Prime Roof Board

Product Long Description
This gypsum cover board is enhanced with a coated glass-mat facer that achieves FM VSH approval rating with adhered 60 or 80 mil (smooth back) JM TPO membrane and standard JM TPO membrande adhesives when 4'x4' panels are adhered in low rise foam adhesive using the ribbon application with 12" O.C.


DensDeck StormX Prime Roof Board


Meets the requirements of ASTM C 1177

Very Severe Hail: Achieves FM 'VSH' approval with adhered 60 or 80 mil (smooth back) JM TPO membrane and standard JM TPO membrane adhesives when 4x4' panels are adhered in low rise foam adhesive ribbons, 12" OC min.

Enhanced Face Mat: Coated fiberglass facer ideal for fully adhered systems provides a broader compatibility and higher performance with roofing adhesives.

Fire Performance: FM Class 1 for fire barrier requirements and UL Class A unlimited slope with excellent surface burning characteristics. 5/8" thickness meets the requirements of Type X per ASTM C 1177.


Maximizing Your Roof's Protection From Hail

When it comes to your roof, hail can cause significant damage. However, incorporating the appropriate cover board into your roofing system can provide you with superior protection. Upgrade your roof to VSH-rated with DensDeck StormX Prime Roof Board today!

FM VSH Approval Rating Image of Hand with a Hail Ball and Custom Logo

Very Severe Hail is two inches or wider in diameter.

Hail can fall as speeds up to 72 mph

The Very Severe Hail region was recently expanded. Are you in the danger zone? Visit the FM Global natural hazards map here.


Building Owner Resources

Johns Manville offers one of the most comprehensive portfolios of commercial low-slope roofing solutions. We have a long standing dedication to providing solution-based systems for building owners.

Codes Corner

Here you will find quick links and cheat sheets to Johns Manville roofing systems code approvals and ratings. 

Guarantees and Roof Maintenance

Support services can include: conceptual product information, building science, wind uplift data, national and local code understanding, FM Global® and UL® regulations, fastening patterns and sheet layouts, installation guidelines and standard details.

Recycling Resources

Re-roofing mechanically attached or ballasted insulated single-ply systems now have the potential for recycling versus contributing to a landfill.

SmartBinder Resource Library 

Your resource for all JM documents in one place. 

Submittal Wizard

The Submittal Wizard is a tool to help you pull together the necessary documents for your submittal package.

Explore More

Commercial Roofing News


Commercial Roofing Blog

Watch On-Demand

Video Library

Roofing Video Library

Expand Your Knowledge


Training Page