2001 ASD Supplements - unprotected PDF - American Wood Council

ASD STRUCTURAL LUMBER SUPPLEMENTL-51Table 7.7 Rafters With L/240 Deflection LimitationDesign CriteriaDeflection: For 40 psf live loadLimited to span in inches divided by 240Strength: Live load of 40 psf plus dead load of 15 psf determines the required bending design valueRafterSize Spacing Bending Design Value, F b, (psi)(in.) (in.) 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 270012.0 5-3 6-1 6-9 7-5 8-0 8-7 9-1 9-7 10-0 10-6 10-11 11-4 11-9 12-1 12-6 12-10 13-2 13-6 13-10 14-2 14-5 † 14-5 † 14-5 † 14-5 † 14-5 †16.0 4-6 5-3 5-10 6-5 6-11 7-5 7-10 8-3 8-8 9-1 9-5 9-10 10-2 10-6 10-10 11-1 11-5 11-9 12-0 12-4 12-7 12-10 13-1 † 13-1 † 13-12 × 6†19.2 4-2 4-9 5-4 5-10 6-4 6-9 7-2 7-7 7-11 8-3 8-8 8-11 9-3 9-7 9-10 10-2 10-5 10-8 11-0 11-3 11-6 11-9 12-0 12-2 12-4 †24.0 3-8 4-3 4-9 5-3 5-8 6-1 6-5 6-9 7-1 7-5 7-9 8-0 8-3 8-7 8-10 9-1 9-4 9-7 9-10 10-0 10-3 10-6 10-8 10-11 11-112.0 6-11 8-0 8-11 9-9 10-7 11-3 12-0 12-7 13-3 13-10 14-5 14-11 15-5 16-0 16-5 16-11 17-5 17-10 18-3 18-9 19-0 † 19-0 † 19-0 † 19-0 † 19-0 †16.0 6-0 6-11 7-9 8-6 9-2 9-9 10-4 10-11 11-6 12-0 12-6 12-11 13-5 13-10 14-3 14-8 15-1 15-5 15-10 16-3 16-7 16-11 17-3 † 17-3 † 17-3 †2 × 819.2 5-6 6-4 7-1 7-9 8-4 8-11 9-6 10-0 10-6 10-11 11-5 11-10 12-3 12-7 13-0 13-5 13-9 14-1 14-6 14-10 15-2 15-5 15-9 16-1 16-3 †24.0 4-11 5-8 6-4 6-11 7-6 8-0 8-6 8-11 9-4 9-9 10-2 10-7 10-11 11-3 11-8 12-0 12-4 12-7 12-11 13-3 13-6 13-10 14-1 14-5 14-812.0 8-10 10-2 11-5 12-6 13-6 14-5 15-3 16-1 16-11 17-8 18-4 19-1 19-9 20-4 21-0 21-7 22-2 22-9 23-4 23-11 24-3 † 24-3 † 24-3 † 24-3 † 24-3 †16.0 7-8 8-10 9-10 10-10 11-8 12-6 13-3 13-11 14-8 15-3 15-11 16-6 17-1 17-8 18-2 18-9 19-3 19-9 20-2 20-8 21-2 21-7 22-1 † 22-1 † 22-12 × 10†19.2 7-0 8-1 9-0 9-10 10-8 11-5 12-1 12-9 13-4 13-11 14-6 15-1 15-7 16-1 16-7 17-1 17-7 18-0 18-5 18-11 19-4 19-9 20-2 20-6 20-9 †24.0 6-3 7-2 8-1 8-10 9-6 10-2 10-10 11-5 11-11 12-6 13-0 13-6 13-11 14-5 14-10 15-3 15-8 16-1 16-6 16-11 17-3 17-8 18-0 18-4 18-912.0 10-9 12-5 13-10 15-2 16-5 17-6 18-7 19-7 20-6 21-5 22-4 23-2 24-0 24-9 25-6 26-0* 26-0* 26-0* 26-0* 26-0* 26-0* 26-0* 26-0* 26-0* 26-0*16.0 9-3 10-9 12-0 13-2 14-2 15-2 16-1 17-0 17-9 18-7 19-4 20-1 20-9 21-5 22-1 22-9 23-5 24-0 24-7 25-2 25-9 26-0* 26-0* 26-0* 26-0*2 × 1219.2 8-6 9-10 10-11 12-0 12-11 13-10 14-8 15-6 16-3 17-0 17-8 18-4 19-0 19-7 20-2 20-9 21-4 21-11 22-5 23-0 23-6 24-0 24-6 25-0 25-3 †24.0 7-7 8-9 9-10 10-9 11-7 12-5 13-2 13-10 14-6 15-2 15-9 16-5 17-0 17-6 18-1 18-7 19-1 19-7 20-1 20-6 21-0 21-5 21-11 22-4 22-912.0 0.12 0.19 0.27 0.35 0.44 0.54 0.65 0.76 0.88 1.00 1.13 1.26 1.40 1.54 1.68 1.83 1.99 2.15 2.31 2.48 2.60 2.60 2.60 2.60 2.6016.0 0.11 0.17 0.23 0.31 0.39 0.47 0.56 0.66 0.76 0.86 0.98 1.09 1.21 1.33 1.46 1.59 1.72 1.86 2.00 2.15 2.29 2.45 2.60 2.60 2.60E19.2 0.10 0.15 0.21 0.28 0.35 0.43 0.51 0.60 0.69 0.79 0.89 0.99 1.10 1.22 1.33 1.45 1.57 1.70 1.83 1.96 2.09 2.23 2.37 2.52 2.6024.0 0.09 0.14 0.19 0.25 0.31 0.38 0.46 0.54 0.62 0.71 0.80 0.89 0.99 1.09 1.19 1.30 1.41 1.52 1.63 1.75 1.87 2.00 2.12 2.25 2.38Note: The required modulus of elasticity, E, in 1,000,000 pounds per square inch is shown at the bottom of each table, is limited to 2.6 million pounds per square inch, and is applicable to all lumber sizesshown.* Spans are shown in feet-inches and are limited to 26 feet. Check sources of supply for availability of lumber in lengths greater than 20'.†Spans are controlled by maximum E value of 2.6 million psi.7SPAN TABLESAMERICAN FOREST & PAPER ASSOCIATION