Fire retardant lumber, also called FRTW, is used when a project has a requirement to reduce the structures’ ability to burn and to reduce the structures’ contribution to the spread of fire. Most fire retardant materials also reduce the development of smoke and the release of hazardous gases in the event of a structural fire. Shown is an example of treated fire retardant lumber used for interior non-damp environments. [For photo, See PDF or View in Full Issue.]
The use of FRTW lumber can increase a component manufacturers’ market, allowing them to participate in new segments of construction. To expand your market and start offering FRTW, however, you should begin by considering a few important aspects of its use and special handling issues that impact manufacturing. What special handling is required? Are there any special concerns? Can FRTW get wet?
Points to Consider
- FRTW can impact moisture content by absorbing moisture after its manufacture.
- FRTW is normally hygroscopic, that is, it attracts and holds water molecules through absorption from either direct contact or from the atmosphere.
- FRTW requires adjusted values when designing trusses. Most plate manufacturers reduce the allowable values for lumber of the same properties.
- Some fire retardant treatments can make lumber brittle; that means, using finish rollers may lead to breaks and may make the lumber unsuitable, so you should plan on having extra lumber to break.
- FRTW can increase potential corrosion of metal connectors. Shown is an example of corrosion attributed to wet installations. [For photo, See PDF or View in Full Issue.]
- Unless labeled for exterior use, FRTW should not be subjected to excessive or prolonged exposure to moisture because this can affect the performance of the fire retardant treatment.
- In some cases, the project must be kept dry from your receipt of FRTW to your delivery of completed trusses.
- Some fire retardant chemicals have been suspected of contributing to rising rates of reproductive and endocrine problems, neurodevelopmental problems in children, and certain types of cancer; therefore, lumber should be controlled and a method for waste needs to be considered.
- For more information on “Fire-Retardant-Treated Wood and Alternative Methods,” see this previous article by Robert Glowinski, written when he was President and CEO of American Wood Council (AWC).
The Bottom Line
So, does FRTW require special handling? Absolutely, yes. Therefore, special efforts must be made to understand the specific precautions. This information should be available from your FRTW source. Some fire retardant wood can get wet, but not all. Wood that has been treated to control damp applications is designed to prevent water leaching, which removes needed chemicals or allows these chemicals to contribute to pollution concerns. This material should always be protected from excessive moisture. Some of the chemicals used to treat wood have been cited by health officials, so careful understanding of the specific product must be investigated to provide understanding of what PPE is required, how dust and waste should be handled, and what additional equipment limitations may exist. But once you understand the dynamics of FRTW, then you can begin offering it to your customers too.
An ANSI/TPI 1 3rd Party Quality Assurance Authorized Agent covering the Southeastern United States, Glenn Traylor is an independent consultant with almost four decades of experience in the structural building components industry. Glenn serves as a trainer-evaluator-auditor covering sales, design, PM, QA, customer service, and production elements of the truss industry. He also provides project management specifically pertaining to structural building components, including on-site inspections and ANSI/TPI 1 compliance assessments. Glenn provides new plant and retrofit designs, equipment evaluations, ROI, capacity analysis, and CPM analysis.