Fire retardant treatment (FRT) was developed to be applied to building materials, such as dimension lumber (i.e., fire retardant-treated wood or FRTW) and plywood, to reduce the ability of the wood to fuel a fire. This treatment can allow FRT materials to be used as an acceptable alternative for building code requirements that specify noncombustible material in specific applications. This treatment does not make wood a noncombustible material as defined by the building codes, but it does reduce the ability of the treated wood to contribute significantly to the growth of a fire.
While reducing the flammability of the wood, FRT may also degrade the structural properties of the wood. The treatments must be carefully applied according to applicable standards. Depending on the treatment used, constructing buildings with FRT materials may require a reduction in the design values of the wood and a reduction in the capacity of connectors used in conjunction with FRTW.
There are FRT applications for both interior and exterior use. The focus of this report is on interior use of FRTW. The wood or product is impregnated with a mineral salt or water insoluble organic retardant, generally a resin polymer or graft polymer that reduces the temperature of thermal degradation, results in more charring, and decreases flammable volatiles. This report is limited to a consideration of when and how FRTW is permitted to be used in truss design.
The Structural Building Components Association (SBCA) has developed this Research Report to provide a clear perspective on the use of fire retardant materials used in construction. The analysis is based on code requirements developed by the International Code Council (ICC) within the 2012 and 2015 International Building Code (IBC), ANSI/TPI 1-2014 National Design Standard for Metal Plate Connected Wood Truss Construction, ANSI/AWC NDS-2015 National Design Specification (NDS) for Wood Construction and other industry resources.
While reducing the flammability of the wood, FRT may also degrade the structural properties of the wood. The treatments must be carefully applied according to applicable standards. Depending on the treatment used, constructing buildings with FRT materials may require a reduction in the design values of the wood and a reduction in the capacity of connectors used in conjunction with FRTW.
There are FRT applications for both interior and exterior use. The focus of this report is on interior use of FRTW. The wood or product is impregnated with a mineral salt or water insoluble organic retardant, generally a resin polymer or graft polymer that reduces the temperature of thermal degradation, results in more charring, and decreases flammable volatiles. This report is limited to a consideration of when and how FRTW is permitted to be used in truss design.
The Structural Building Components Association (SBCA) has developed this Research Report to provide a clear perspective on the use of fire retardant materials used in construction. The analysis is based on code requirements developed by the International Code Council (ICC) within the 2012 and 2015 International Building Code (IBC), ANSI/TPI 1-2014 National Design Standard for Metal Plate Connected Wood Truss Construction, ANSI/AWC NDS-2015 National Design Specification (NDS) for Wood Construction and other industry resources.
This legacy SBCA Research Report represents information and code requirements current as of the publication date shown. However, codes and standards change periodically. The user is encouraged to verify the referenced information is still current and conforms to current code requirements.
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