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Purlin CHECK 420911 <br /> Base on actual requirements <br /> (Treat as uniformally loaded simple beam) <br /> Moment w1^2/8 <br /> Deflection 5w1^4/384EI <br /> Select species <br /> Species/Grade 1NWPA Douglas-Fir-Larch No. 1 and better <br /> Size 2x8 <br /> Fb 1200 psi (Normal) <br /> Cf 1.2 Size Factor <br /> Cr 1.15 Repetitive use factor <br /> Fb' = Fb*Cf*Cr* Cd <br /> Fb' 1656 psi (Normal) Cd = 1 <br /> 1904 psi (Snow) Cd = 1.15 <br /> 2650 psi (Wind) Cd = 1.6 <br /> E 1800000 psi <br /> I 47.64 I N4 <br /> S 13.14 IN3 <br /> Velocity Pressure 16.38 <br /> Ce 1.142 <br /> 1 <br /> Cq -1.3 <br /> Input Span 12 ft <br /> Overide span 0 ft <br /> 144 in <br /> Spacing 2 ft <br /> Pitch 4 /12 0.321751 <br /> 0.948683 <br /> Wind <br /> w -48.65 #/ft <br /> -4.05 #/in <br /> Dead Load 5 psf <br /> w 10 #/ft <br /> 0.83 #/in <br /> Live Load 50 <br /> w 94.87 #/ft <br /> 7.91 #/in <br /> Check Two conditions 1 DL+LL <br /> 2 DL+W <br /> CASE Moment f=Mom/S Allowable Deflection L/180 L/240 <br /> 1 22651.56 1723.86 1904 OK 0.57 0.8 0.6 <br /> 2 8347.83 635.30 2650 OK -0.21 0.8 0.6 <br /> 13 <br />