2001 ASD Supplements - unprotected PDF - American Wood Council

ASD STRUCTURAL LUMBER SUPPLEMENTL-11Table 4.4 Size Factor, C F1,2,3F bNominal ThicknessGrades Width 2" & 3" 4" F tF c4" & less 1.5 1.5 1.5 1.15Sel. Struct., 5" 1.4 1.4 1.4 1.10No. 1 & Better, 6" 1.3 1.3 1.3 1.10No. 1, No. 2, 8" 1.2 1.3 1.2 1.05No. 3 10" 1.1 1.2 1.1 1.0012" 1.0 1.1 1.0 1.00$ 14" 0.9 1.0 0.9 0.904" & less 1.1 1.1 1.1 1.05Stud 5" & 6" 1.0 1.0 1.0 1.008" & wider Use No. 3 grade base values and size factorsConst., Stand. 4" & less 1.0 1.0 1.0 1.00Utility4" 1.0 1.0 1.0 1.002" & 3" 0.4 — 0.4 0.601For Southern Pine and Mixed Southern Pine dimension lumber (tabulated design values in Table 4B of NDS Supplement), the value of C F is 1.0 for allproperties and all sizes 12" in width and less, except for material 4" in thickness and 8" and wider, where C F is 1.1 for F b . See NDS Supplement for additionalrequirements.2For mechanically graded dimension lumber (both MSR and MEL, tabulated design values in Table 4C of NDS Supplement), the value of C F is 1.0 for allproperties and all sizes.3For members with tabulated design values listed in Table 4D of NDS Supplement, C F for F b is computed as (12/d) 1/9 ≤ 1.0, where d is the depth of the member.C F for other properties is 1.0. See NDS Supplement for additional requirements.4DESIGN ADJUSTMENT FACTORSTable 4.5 Flat Use Factor, C fuTable 4.6 Incising Factor, C iWidthThickness2" and 3" 4"2" & 3" 1.00 —4" 1.10 1.005" 1.10 1.056" 1.15 1.058" 1.15 1.0510" & wider 1.20 1.10Design ValueC iE 0.95F b , F t , F c 0.80F v , F c⊥ 1.00AMERICAN FOREST & PAPER ASSOCIATION