In order for fire to spread, it requires a steady diet of food and oxygen. When you build with FlameFreez® brand fire retardant treated wood (FRTW), you can largely eliminate one of the sources of food: the wood used in construction.

When fire retardant treated lumber and plywood products are exposed to open flames, they form a “char” that allows the wood to maintain its strength and stability while simultaneously reducing flame spread. This passive protection not only helps maintain the integrity of a structure to give fire services more time to respond but also reduces smoke development which is a common cause of death in a fire event.


FlameFreez® brand FRTW products are recommended for use in commercial and residential applications. As an Interior Type A Fire Retardant, they can be used for the following interior areas not exposed to the weather or wetting and where the adopted building code permits the use of wood or fire-retardant treated wood.*

  • Sill plates
  • Roof trusses
  • Rafters
  • Studs and other framing members
  • Plywood roof, wall and floor sheathing
  • Beams, joists and purlins
  • Plywood sub-flooring
  • Steps and stairways
  • Partition walls
  • Blocking and furring
  • Window and door headers


  • Pressure treated with FlamePRO® fire retardant chemicals to provide long-term protection (not a paint or coating)
  • Treated with an Interior Type A High Temperature (HT) fire retardant
  • Proven formulation based on the American Wood Protection Association P50 Standard for Fire Retardants
  • Meets the requirements for FRTW listed in the International Code Council Acceptance Criteria ICC AC66 conforming with the International Residential and the International Building Codes (IRC & IBC)
  • Complies with AWPA UC-1 and UCFA use category systems
  • Treatment process meets AWPA T1 standard
  • 50-Year Limited Warranty against structural failure due to heat or humidity
  • Recommended for above-ground, weather-protected applications
  • Building code compliant*
  • Kiln dried after treatment
  • Strength tested under high temperature and high humidity conditions
  • Cut or sawn with typical wood-working tools
  • Non-corrosive
  • Can be painted or stained


FlameFreez® brand fire retardant treated wood (FRTW) products are treated with the FlamePRO® fire retardant chemicals from Koppers Performance Chemicals. FlamePRO® products have received the following certifications:

  • 1 Hour Tested Wall Assembly (ASTM E119)**
  • 2 Hour Tested Wall Assembly (ASTM E119)**
  • Meets all major model building code requirements as described in the ICC Evaluation Services, Inc. ESR-4244
  • UL Classified with an FR-S Rating for flame spread and smoke development values of 25 or less. Complies with AWPA UC-1 and UCFA use category systems and meets the AWPA T1 standard
  • UL GREENGUARD GOLD Certification assures low volatile organic compound (VOC) emissions and certifies that these products are suitable for use in schools, offices and other sensitive environments
  • Backed by 50 Year Limited Warranty from Koppers Performance Chemicals, Inc.
  • Hygroscopicity testing conducted by a third-party independent laboratory has confirmed that compared to untreated wood, these products do not pick up excessive moisture under ASTM D3201 test conditions


The chemical used in manufacturing FlameFreez® brand products have been evaluated for corrosivity in accordance with AWPA Standard E12 for a variety of metals. The corrosion rates for carbon steel, galvanized steel, aluminum, red brass, and copper are not significantly increased when the treated wood products are used as recommended by the manufacturer and properly sized for the materials selected.


*Consult local building codes to determine the specific uses allowed.
**See ICC ES Report, ESR-4244

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