What are the Requirements for Finger-Jointed Lumber used in Fire-Resistance-Rated Assemblies?

The 2012 IBC Section 2303.1.1.2 states: Approved end-jointed lumber is permitted to be used interchangeably with solid-sawn members of the same species and grade. End-jointed lumber used in an assembly required to have a fire-resistance-rating shall have the designation “Heat Resistant Adhesive” or “HRA” included in its grade mark. In 2009 the American Lumber Standards Committee (ALSC) modified the ALSC Glued Lumber Policy to add elevated-temperature performance requirements for end-jointed lumber adhesives intended for use in fire-resistance-rated assemblies. End-jointed lumber manufactured with adhesives which meet the new requirements is being designated as “Heat Resistant Adhesive” or “HRA” on the grade stamp.

The ALSC Glued Lumber Policy requires that Heat Resistant Adhesives be qualified in accordance with one of two new ASTM standards, D7374-08 Practice for Evaluating Elevated Temperature Performance of Adhesives Used in End-Jointed Lumber and D7470-08 Practice for Evaluating Elevated Temperature Performance of End-Jointed Lumber Studs. Both standards require a wall assembly made with end-jointed lumber to be subjected to the ASTM E119 fire test. The tested-adhesive qualifies as a Heat Resistant Adhesive if the wall assembly achieves a one-hour fire-resistance-rating. End-jointed lumber manufactured with a Heat Resistant Adhesive under an auditing program of an ALSC-accredited grading agency is allowed to carry the HRA mark on the grade-stamp. End-jointed lumber manufactured with an adhesive not qualified as a Heat Resistant Adhesive will be designated as “Non-Heat Resistant Adhesive” or “non-HRA” on the grade stamp. Lumber carrying the HRA mark is permitted to be used interchangeably with solid-sawn members of the same species and grade in fire-resistance-rated applications.

For more information, please contact AWC at 202-463-4713 or info@awc.org.