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WILKINSON 1/9/2019 SDA Job# ' 8448 1 <br /> Collar Tie Design <br /> Rafter spacing = 24 in <br /> Live load = 25 PSF <br /> Dead load = 15 PSF <br /> Roof slope = 8in/12in <br /> 12 80 ptF <br /> 54 inches <br /> 980 Ibs <br /> 110.5 ft / <br /> Tension in collar tie: <br /> RA= 840 lbs <br /> FM8 = (840 x 10.5 ft) - (80 x 11 x 10.5 <br /> T= 980 lbs <br /> Collar tie/rafter grade oF#1 v' <br /> Nails: <br /> Use 16d nails Z= 141 lbs CD = 1.15 <br /> Diameter= 0.162" 1.5"/ 1.62" = 0.93 ---► Nail penatration reduction <br /> ' 141 x 0.93 x 1.15= 150 lbs/nail <br /> ---♦ Use(7) 16d nails @ each collar tie/rafter Tension <br /> conn.w/ 2x4 collar ties of same grade TTOTAL= 2 x 980 = 1960 lbs <br /> TALLOW= 5.25 x 675 x 1.15 =4075 lbs <br /> Size Rafters: — Collar tie tension OK <br /> 653 lbs (Perp. Component of T) 0 <br /> 80 PLF Repetitive member(Cr= 1.15) <br /> 4, j4 j ; 4 k CF = 1.1 Lu = 1.0ft <br /> / L Bending: s <br /> 3.75 ft S,�,�Req'd = 23.52 in —r 2x10 DF#1 <br /> / 10.5 ft / <br /> Shear: <br /> Max moment= 31050 in-it Area Req'd = 5.29 in —► 2x6 DF#1 <br /> Max shear= 840 lbs <br /> Deflection: (L/240) <br /> --� Use 2x10 DF#1 rafters @ 24" o/c Ix Req'd = 18.09 in4-♦ 2x6 F#1 <br />