Issue link: http://alpine.uberflip.com/i/411909
39'3" 17' 32' These allowable spans are based on NDS 2005. Maximum deflection is limited by L/360 or L/480 under 1 live load. Basic Lumber Design Values are F =2000 psi (b) F =1100 psi F =2000 psi E=1,800,000 psi Duration (t) (c) Of Load = 1.00. Spacing of trusses are center-to-center (in inches). Top Chord Dead Load = 10 psf. Bottom Chord Dead Load = 5 psf. Center Line Chase = 24" max. Trusses must be designed for any special loading, such as concentrated loads. Other floor and roof loading conditions and a variety of species and other lumber grades are available. Center Deflection Truss Depth Truss Depth Spacing Limit 12" 14" 16" 18" 20" 22" 12" 14" 16" 18" 20" 22" 16" o.c. L/360 22'2" 24'11" 26'10" 28'8" 30'4" 31'11" 19'0" 20'9" 22'4" 23'10" 25'3" 26'7" L/480 20'2" 22'7" 24'11" 27'2" 29'4" 31'5" 18'0" 20'2" 22"4' 23'10" 25'3" 26'7" 19.2" o.c. L/360 20'9" 22'8" 24'4" 26'0" 27'6" 29'0" 17'3" 18'9" 20'3" 21'7" 22'10" 24'1" L/480 18'11" 21'3" 23'6" 25'7" 27'6" 29'0" 16'11" 18'9" 20'3" 21'7" 22'10" 24'1" 24" o.c. L/360 18'5" 20'1" 21'7" 23'1" 24'5" 25'9" 15'2" 16'7" 17'10" 19'1" 20'2" 21'3" L/480 17'7" 19'9" 21'7" 23'1" 24'5" 25'9" 15'2" 16'7" 17'10" 19'1" 20'2" 21'3" 12" 14" 16" 18" 20" 22" 12" 14" 16" 18" 20" 22" 16" o.c. L/360 19'4" 21'4" 23'0" 24'6" 26'0" 27'4" 16'3" 17'9" 19'2" 20'5" 21'8" 22'9" L/480 17'7" 19'9" 21'10" 23'9" 25'8" 27'4" 15'9" 17'8" 19'2" 20'5" 21'8" 22'9" 19.2" o.c. L/360 17'9" 19'4" 20'10" 22'3" 23'7" 24'10" 14'9" 16'1" 17'4" 18'6" 19'7" 20'7" L/480 16'7" 18'7" 20'6" 22'3" 23'7" 24'10" 14'9" 16'1" 17'4" 18'6" 19'7" 20'7" 24" o.c. L/360 15'9" 17'2" 18'6" 19'9" 20'11" 22'0" 13'0" 14'2" 15'3" 16'4" 17'3" 18'2" L/480 15'4" 17'2" 18'6" 19'9" 20'11" 22'0" 13'0" 14'2" 15'3" 16'4" 17'3" 18'2" 12" 14" 16" 18" 20" 22" 12" 14" 16" 18" 20" 22" 16" o.c. L/360 16'11" 18'6" 19'11" 21'3" 22'6" 23'8" 14'1" 15'5" 16'7" 17'8" 18'9" 19'9" L/480 15'8" 17'7" 19'5" 21'2" 22'6" 23'8" 14'0" 15'5" 16'7" 17'8" 18'9" 19'9" 19.2" o.c. L/360 15'4" 16'9" 18'1" 19'3" 20'5" 21'6" 12'9" 13'11" 15'0" 16'0" 16'11" 17'10" L/480 14'9" 16'6" 18'1" 19'3" 20'5" 21'6" 12'9" 13'11" 15'0" 16'0" 16'11" 17'10" 24" o.c. L/360 13'8" 14'10" 16'0" 17'1" 18'1" 19'1" 11'3" 12'3" 13'3" 14'1" 14'11" 15'9" L/480 13'8" 14'10" 16'0" 17'1" 18'1" 19'1" 11'3" 12'3" 13'3" 14'1" 14'11" 15'9" (1) Vibration Control -- Research by Virginia Tech indicates that L/480 live load deflection criteria provides a high degree of resistance to floor vibration (bounce). The building designer desiring this benefit may choose to specify an L/480 live load deflection criteria to be used for the floor trusses. 40 PSF Live Load 55 PSF Total Load 85 PSF Live Load 100 PSF Total Load 60 PSF Live Load 75 PSF Total Load 40 PSF Live Load 55 PSF Total Load 85 PSF Live Load 100 PSF Total Load 60 PSF Live Load 75 PSF Total Load 4x2 Lumber 3x2 Lumber 3 / " 1 2 2 / " 1 2 1 / " 1 2 1 / " 1 2 FLOOR TRUSSES Span Tables for Span Tables for 5 www.alpineitw.com