Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System
A code-compliant multi-layer walking deck & roof covering waterproofing system featuring TetraCrete®. Designed for plywood decks, roof decks and other common surfaces that require a Class A fire classification. ICC-ES listed (ESR-3672). Superior protection for residential, commercial and high-performance deck areas.
Key Benefits
Code Compliant
ICC-ES listed (ESR-3672)
Class A Fire Rated
Highest 2-hour fire rating available
Weather Resistant
Superior protection against harsh weather
Impact Resistant
Durable protection against physical damage
Recommended Applications
Building Code Compliant Multi-Layer System
The Deck Flex W.M. Walking Deck & Roof Covering System utilizes a comprehensive 6-layer application approach for maximum protection and fire resistance.
Exploded view of the 6-layer W.M. system
Metal Lath Layer
Strengthens surface and bonds with proprietary cementitious layer
TetraCrete #3
Proprietary additive modified cementitious blend for proven protection
Fiberglass Layer
Increased flexibility and improved adhesion with acrylic base coat
Base Coat Layer
Added durability and weather resistance
TetraCrete #2 Texture Layer
Beautifies and provides slip resistance as necessary
Top Coat Layer
Improved aesthetics, color, surface protection and maintainability
Deck Flex W.M. installed on plywood roof deck with solar
Finished deck surface
Technical Specifications
Powered by TetraCrete®
Our concrete system delivers four key properties for superior performance
Fire-Resistance
Achieves stringent fire ratings for roof decks and walking surfaces
Flexibility
Elastomeric properties accommodate structural movement and thermal expansion
Durability
Withstands heavy foot traffic and commercial use for years of protection
Weather-Protection
Resists UV rays, rain, extreme temperatures, and freeze-thaw cycles
Drying Times
Drying times vary between 1-4 hours depending on weather conditions and application stage.
Weather Dependent
Allow adequate drying time between layers. Temperature, humidity, and airflow affect cure rates.
Frequently Asked Questions
What is the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
The Deck Flex W.M. Fire Retardant System is a walking deck and roof covering system intended for application over plywood decks. It is a multi-layer system that is produced at the jobsite and consists of several components, including TetraCrete No. 3 Gray, TetraCrete No. 2 White, TetraCrete Additive, fiberglass mat, and Deck Flex coatings. When installed as described in Section 4.3 of ESR-3672, it is used as a Class A roof covering. It can also be used as a component of a one-hour fire-resistance-rated assembly.
What is the fire rating for the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
When the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System is applied over a plywood deck as described in Section 4.2.1 of ESR-3672, with a maximum slope of 1/4 inch to a horizontal foot (2.1 percent slope), the system has a Class A roof classification.
Can the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System be used in a one-hour fire-resistance-rated assembly?
Yes. When the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System is installed over 5/8-inch-thick exterior-grade plywood with 2-by-10 wood joists spaced at 16 inches on center, the assembly can be recognized as an alternative for the double wood floor described in Item 13-1.4 of Table 721.1(3) of the 2021, 2018, 2015 and 2012 IBC.
What are the material mixing ratios for the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
Cementitious Layer: Forty-five to fifty pounds (20.4 to 22.7 kg) of TetraCrete No. 3 Gray are mixed with 1 gallon (3.7 L) of TetraCrete Additive. Texture Coat Layer: Forty-five to 50 pounds (20.4 to 22.7 kg) of TetraCrete No. 2 White are mixed with one gallon (3.8L) of TetraCrete Additive.
What are the material coverage rates for the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
TetraCrete No. 3 Gray Mixture: Maximum coverage of 50 square feet per mixed batch. Deck Flex Base Coat: 60 to 75 square feet per gallon. Deck Flex Texture Coat: 90 to 100 square feet per gallon. Deck Flex Top Coat: 150 to 180 square feet per gallon.
What are the required dry times between coats for the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
Cement Base (TetraCrete No. 3 Gray layer): Must cure for 24 hours. Deck Flex Base Coat: Must dry for two to four hours (depending on weather). Deck Flex Texture Coat: Must dry for one to two hours.
What are the substrate requirements for the Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System?
The Deck Flex W.M. Walking Deck & Roof Covering Waterproofing System is installed over exterior-grade plywood substrates. The plywood must be a minimum of 5/8 inch (15.9 mm) thick. All substrates must be structurally sound, free of contaminants (like water, paint, bond breakers), free of projections or depressions, and sloped for proper drainage. All plywood joints must be over framing members or blocked with minimum 2-by-4 blocking. For detailed specifications, see our technical specifications page.
Technical Documentation
ICC-ES ESR-3672 Report
Class A fire rating certification and code compliance
Learn about AC39 Acceptance Criteria
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