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ADEQUACY CHECK OF LAG SCREWS AND <br />EXISTING FRAMING DUE TO WIND FORCES <br />TYPICAL PROFILE: <br />'Wind Pressure, P <br />404 <br />= 24" o.c.ralter spacing rafter spacing = 24" o.c <br />Legend: <br />1. Exisiting 2*4 Roof Rafter w/ purlin supports,(Total Span of 13 ft) <br />2. Solar Panel Track Rail <br />3.5/16" ¢ Lag Screw w/Min. 2.5" Penetration into Rafter <br />Uplift from Solar Panel Wind Forces, U <br />Design Wind Pressure, P = <br />Trib. Depth for Each Rail, Td - <br />ScrewAnchor Spacing, S = <br />Resisting Weight of Panels, D = TdxSx3 psf = <br />Uplift Force on Each Screw, U= PxTdxS -D= <br />Check Adequacy of Laa Screw for Pull-Out <br />-30.9 psf (See Attached Wind Analysis) <br />2.55 ft (5.1 ft + 2) <br />4 ft (max.) <br />30.6 lbs <br />-284.6 lbs (Upwards) <br />-Uplift Resistance Provided by 5/16" ¢ Lag Screw with Minimum 2.5 in. <br />Penetration into Douglas Fir Larch Member Per NDS (Table 11.2A) =266 lbs/in <br />Allowable Uplift Load, Ua = 1.6 x 2.5 x 266 =1064 lbs > U = 285 lbs 4 OKAY <br />Existina Framina Member Check* <br />purlin span <br />Roof Dead Load <br />Panel Deal Load <br />Total Dead Load, DL <br />Screw Uplift Loads, W <br />6.5 ft o.c. <br />12 psf <br />3 psf <br />15 psi x 2 feet spacing =30 pif <br />-284.6 lbs (Max. 4 Anchors/Stand-offs on Rafter) <br />*See attached Enercalc Output for Analysis Results <br />e <br />b 4