Understanding the Fire Retardant Treated Wood Requirements in the International Building Code
Fire Retardant Treated Wood Requirements in the International Building Code
In recent years, the International Building Code (IBC) has undergone significant updates, particularly in its requirements for Fire Retardant Treated Wood (FRTW). These changes aim to enhance clarity and ensure that FRTW meets stringent safety standards in construction projects. Whether you’re a retailer, lumberyard owner, building code official, or a contractor relying on FRTW, staying informed about these revisions is critical for compliance and safety.
What’s New in the IBC for FRTW?
The latest edition of the IBC emphasizes that FRTW must be impregnated with fire-retardant chemicals through a pressure process or other approved methods during the manufacturing stage. This is a key distinction from past practices, where some interpretations allowed surface-applied treatments—like paints, stains, or coatings—to be marketed as FRTW. The updated code explicitly disallows these superficial treatments, stating they do not meet the necessary standards for fire resistance.
According to Section 2303.2 of the 2021 IBC, FRTW is defined as:
“Any product that, when impregnated with chemicals by a pressure process or other means during manufacture, shall have, when tested in accordance with ASTM E84 or UL 723, a listed flame spread index of 25 or less. Additionally, the ASTM E84 or UL723 test shall be continued for a 20-minute period and the flame front shall not progress more than 10½ feet (3200mm) beyond the center line of the burners at any time during the test.”
This means that for wood to qualify as FRTW, it must undergo rigorous testing and demonstrate a flame spread index of 25 or less, even after an extended 20-minute test period. The treatment must be embedded into the wood during manufacturing, ensuring comprehensive and permanent protection across all surfaces.
Clarifying “Other Means During Manufacture”
The phrase “other means during manufacture” might sound vague, but Section 2303.2.2 of the 2021 IBC provides further clarification:
“For wood products impregnated with chemicals by other means during manufacture, the treatment shall be an integral part of the manufacturing process of the wood product. The treatment shall provide permanent protection to all surfaces of the wood product. The use of paints, stains or other surface treatments is not an approved method of protection as required in this section.”
This section reinforces that surface treatments applied after manufacturing do not suffice. The fire-retardant properties must be an inherent part of the wood product itself, not a superficial layer that could wear off or fail under extreme conditions.
Why These Changes Matter
In the past, the ambiguity in the code led to some products being incorrectly marketed as FRTW despite relying solely on surface treatments. The updated IBC eliminates this gray area, setting a clear benchmark for what qualifies as compliant FRTW. This ensures that buildings constructed with FRTW can better withstand fire hazards, protecting both property and lives.
For those involved in the supply chain or construction process, these updates mean it’s more important than ever to scrutinize product labels and documentation. Retailers and lumberyards should verify that their FRTW stock meets these requirements, while builders and inspectors must confirm compliance on-site. Using non-compliant materials could lead to costly rework, legal liabilities, or, worse, compromised safety.
Choosing Compliant FRTW
If you’re sourcing FRTW, look for products that explicitly state they are pressure-impregnated and meet the ASTM E84 or UL 723 testing standards outlined in the IBC. One example of a reliable option is the FRTW offered by Biewer Lumber Fire Retardant Specialists. All Biewer FRTW products are pressure-impregnated, ensuring they comply with the latest IBC requirements. This makes them suitable for any application where FRTW is mandated, from commercial buildings to residential projects.
Final Thoughts
The updates to the International Building Code reflect a commitment to safety and precision in construction standards. By requiring that FRTW be treated through pressure impregnation or other integral manufacturing processes, the IBC ensures that these materials provide consistent, long-lasting fire resistance. As you plan your next project, take the time to review product specifications and confirm compliance with these revised standards. It’s a small step that can make a big difference in building safer, more resilient structures. Contact Biewer FRTW Fire Retardant Specialists for more information.