How D-Blaze FRTW & Plywood Slow Down the Spread of Flame


D-Blaze logo on multi-family construction photo

How D-Blaze® works

D-Blaze char
  • D-Blaze converts combustible gases and tars to carbon char at temperatures <550ºF.
  • D-Blaze releases carbon dioxide and water vapor which dilute combustible gases.
  • D-Blaze chars and insulates underlying wood, retards flame spread, reduces smoke generation, and slows destruction.
  • D-Blaze is formulated and then applied by means of pressure treatment in treating plants. Unlike field applied surface coatings, D-Blaze fire retardant treated wood is produced under a quality control program with inspections by Underwriters Laboratories, Inc (UL), Timber Products Inspection (TP), and Southern Pine Inspection Bureau (SPIB).

How fire retardant treated wood (FRTW) is tested 

Tunnel test for FRS rating
  • Underwriters Laboratories Inc., now UL Solutions, conducts flame spread testing in accordance with the requirements of their "Fire Hazard Classification of Building Materials" testing standard, known as UL 723 in the US and CAN/ULC-S102 in Canada.
  • Other test standards used are the National Fire Protection Association's, "Method of Test of Surface Burning Characteristics of Building Materials" test standard, known as NFPA 255 and the American Society of Testing and Materials test standard, known as ASTM E-84.
  • The UL FR-S rating is the flame spread index and smoke developed index and must be less than or equal to 25 in a 30-minute ASTM E-84 or UL 723 tunnel test.
  • D-Blaze® fire retardant treated wood meets this requirement with a flame-spread index of 25 or less when subjected to ASTM E-84 tests of 30 minutes duration without evidence of significant progressive combustion. D-Blaze has a very low smoke rating. See ICC-ES Evaluation Report ESR-2645.
  • Complies with International Building Code® (IBC) 2018, 2015, 2012, 2009, and 2006 and International Residential Code® (IRC) 2018, 2015, 2012, 2009, and 2006
Proof of compliance
frtw stamp
  • The model building codes require that every piece of FRTW wood bear the identification mark of an approved inspection agency. 
  • Each piece of D-Blaze lumber and plywood is marked, typically with an ink stamp bearing the classification mark of Underwriters Laboratories, Inc. (UL), describing its surface burning characteristics, and substantiating third party confirmation of flame spread and smoke developed index. 
  • The mark further identifies the name and location of the treating plant and will show that the material complies with AWPA standards, has been dried after treatment, and qualifies as an Interior Type A, (High Temperature (HT), low hygroscopic product. 
  • Companies may only use the UL mark on or in connection with products that have been investigated by UL and found to be compliant with UL’s requirements. 
  • The UL Building Materials Directory has listed over a dozen species of lumber and several species of plywood acceptable for fire retardant treatment with D-Blaze. Shown are examples of typical Plywood and Lumber Stamps used in the United States. 

Will fire retardant treated wood (FRTW) burn?

townhouse burned
  • Fire retardants do not make the wood non-combustible. 
  • Fire retardant treated wood exposed to fire and flame for an extended time will eventually burn. However, the fire retardants can slow the rate of fire growth to allow occupants to safely evacuate the structure.
  • Fire retardant treated wood will not support a fire.
  • The chemicals used for D-Blaze FRTW are not considered hazardous materials.

Where has D-Blaze been Used?

  • One World Trade Center, New York, NY
  • Chicago Navy Pier, Chicago, IL
  • NASCAR Hall of Fame, Charlotte, NC
  • Legoland Hotel, Carlsbad, CA
  • Ranger Stadium, Arlington TX
  • Multi-family construction 
  • Commercial and Industrial buildings
D-Blaze FRTW used in One World Trade Center and other prominent buildings

D-Blaze Specifications


More information on D-Blaze FRTW


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