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| Performance
of Finger-Jointed Lumber in Fire-Resistance-Rated Wall Assemblies |
The last
sentence of IBC Section 2303.1.1 Sawn Lumber states, “Approved
end-jointed lumber is permitted to be used interchangeably
with solid-sawn members of the same species and grade.” Although
no problems have been brought to our attention with the fire-performance
of end-jointed lumber in the field, in response to concerns
raised by the wood products industry, the American Lumber Standards
Committee (ALSC) recently 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.
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-rated applications.
For more information, please contact AWC at 202-463-4713 or awcinfo@afandpa.org.
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AF&PA/American Wood
Council – March 2009
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