Wednesday, December 17, 2025
As wildfires continue to escalate in severity and frequency, fire-retardant treated wood (FRTW) has become a key player in building materials designed to prevent disaster. However, a recent fire testing program has revealed that not all fire-retardant treatments provide the same level of protection. Despite some manufacturers offering cheaper, unproven alternatives, fire safety experts urge caution, as not all claims live up to real-world scrutiny.
A study commissioned by the Western Wood Preservers Institute (WWPI) and supported by the Southern Forest Products Association (SFPA) sheds light on the discrepancies between two main types of fire-retardant treatments: pressure-treated and non-pressure applied. The study, conducted by an independent lab, compared six different fire-retardant formulations, with three pressure-treated and three non-pressure applied options. The findings were stark—pressure-treated FRTW passed the rigorous fire tests, while many non-pressure applied treatments failed to deliver.
Pressure-Treated Fire-Retardant Wood: Consistent Performance
Pressure-treated wood, subjected to an intense chemical impregnation process under high pressure, is the gold standard in fire-retardant wood products. In the tests conducted, wood treated with pressure-applied fire retardants consistently met the performance requirements specified by the International Building Code (IBC) and ASTM E2768-11 standards. Over the course of 10 tests, none of the pressure-treated samples saw the flame front progress beyond 10.5 feet within 30 minutes—a critical measure of fire resistance for structural components in buildings.
This impressive performance underscores the reliability and effectiveness of pressure-treated FRTW in safeguarding structures. In real-world applications, this type of fire-resistant wood can be used in high-occupancy buildings such as multi-story apartments, where the stakes for fire safety are particularly high.
Non-Pressure Applied Fire-Retardants: A Risky Gamble
The study also tested wood products treated with non-pressure applied fire retardants. These treatments, which are often marketed as cheaper alternatives, simply do not measure up when it comes to fire resistance. Out of 21 samples treated with non-pressure applied fire retardants, 19 failed to meet the required standards, with flames progressing beyond the critical 10.5-foot mark before the 30-minute test duration had elapsed.
Only two of the non-pressure-treated samples managed to stay within the fire resistance limits, but these results are likely due to the specific characteristics of the Select Structural Douglas fir substrate used, which may have influenced their performance. It is important to note that in both cases, untreated control samples were able to perform better than most of the non-pressure treated options, lasting more than 27 minutes before flames breached the 10.5-foot mark.
This gap in performance highlights a fundamental issue: non-pressure applied fire retardants simply cannot be trusted to provide the necessary fire protection in structural applications.
Why Testing and Certification Matter
The tests were conducted following ASTM E2768-11, a fire testing protocol that is specifically outlined in the IBC. This standard is designed to evaluate the effectiveness of fire-retardant-treated wood in preventing fire spread and ensuring that occupants have time to escape a burning building. According to the IBC, structural FRTW must meet these rigorous performance standards, and the testing duration must be extended to 30 minutes. This ensures that, in the event of a fire, both building occupants and first responders have enough time to act safely.
It is crucial to remember that not all fire-retardant treatments are created equal. Manufacturers of non-pressure applied fire retardants often use terms like “code-compliant,” “Class A rated,” and “ASTM E84 tested” to make their products seem equivalent to pressure-treated options. However, these claims do not qualify their products for use as structural FRTW under the IBC guidelines.
The Implications for Building Safety
The findings from this fire testing program send a clear message to builders, contractors, and consumers: when it comes to fire safety, cutting corners is not an option. While non-pressure applied fire retardants may seem like a cost-effective solution, their failure to meet established fire resistance standards can have deadly consequences.
In high-stakes environments like multi-story buildings, using fire-retardant wood that cannot be relied upon in the event of a fire puts everyone at risk—from the occupants to the first responders. With safety as the number one priority, it is essential that only pressure-treated FRTW be used in structural applications to meet the high safety standards set by the IBC.
Conclusion: Prioritize Safety Over Cost
With fire safety codes becoming more stringent in response to the increasing threat of wildfires, it is essential that the construction industry adopts materials that can withstand the most demanding fire testing requirements. The pressure-treated fire-retardant wood products have proven their ability to meet the highest standards, ensuring the safety of both occupants and first responders.
When choosing fire-retardant wood for any construction project, whether residential or commercial, make sure the product meets all fire testing protocols and is backed by reputable certifications. Cutting costs by choosing non-pressure applied fire retardants may offer short-term savings, but the risks associated with their failure to perform under fire conditions are simply too great to ignore.
By choosing pressure-treated FRTW, you can ensure that your buildings are up to code, up to standard, and, most importantly, safe.
Additional Suggestions for Readers:
Stay update, connect with us on LinkedIn.
Tags: building materials, construction safety, fire retardant treatments, fire safety, fire safety codes, fire testing, fire-retardant treated wood, IBC fire code, non-pressure fire retardants, pressure-treated wood, wildfire protection, wood products
