2001 ASD Supplements - unprotected PDF - American Wood Council

ASD STRUCTURAL GLUED LAMINATED TIMBER SUPPLEMENTGL-59To achieve a one-hour fire rating for beams whosedimensions qualify them for this rating, the basic layupmust be modified - one core lamination must be removedfrom the center and the tension face augmented with theaddition of a tension lamination. For more informationconcerning the effects of fire on glued laminated timber,refer to APA EWS Technical Note Y245 or AITC TechnicalNote 7. For determining fire resistance other than onehour, see Section 16.2 of NDS and AF&PA Technical Report10 available at www.awc.org.Table 6.4Minimum Depths at Which Selected Beam Sizes Can Be Adopted forOne-Hour Fire Ratings aaBeam Depth (in.)Beam Width (in.) 3 Sides Exposed 4 Sides Exposed6-3/4 13-1/2 or 13-3/4 27 or 27-1/28-1/2 7-1/2 or 8-1/4 15 or 15-1/88-3/4 6-7/8 or 7-1/2 13-1/2 or 13-3/410-1/2 6 or 6-7/8 12 or 12-3/810-3/4 6 or 6-7/8 12 or 12-3/8Assuming a load factor of 1.0 (design loads are equal to the capacity of the member). The minimumdepths may be reduced when the design loads are less than the member capacity.6OTHER CONSIDERATIONSAPA – The Engineered Wood Association