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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 />««<0 <br />/Spy.** <br />rafter spacing = 24" o.c. jOCk rafter spacing <br />< <br />= 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" 0 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 />Screw Anchor Spacing, S = <br />Resisting Weight of Panels, D = TdxS*3 psf = <br />UpliR Force on Each Screw, U= PxTdxS -D= <br />Check Adequacvof Lag 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" 4 Lag Screw with Minimum 2.5 in. <br />Penetration into Douglas Fir Larch Member Per NDS (Table 11.2A) =266 Ibshn <br />Allowable Uplift Load, Ua = 1.6 x 2.5 x 266 =1064 lbs >U= 285 lbs e OKAY <br />Existinci FraminG 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 psT <br />3 psf <br />15 psf 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