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Loyd W. Martin Solar Structures Engineering <br />2510 W. 237th St. #206 Torrance, CA 90505 Tel:1.310.464.1804 <br />Email: loydwmartin@gmail.com www.loydwmartin.com <br />Check attachment of Support to Existing Structure for Wind Uplift - Cont'd <br />Tributary Area to Each Solar Mount = 4 ft. x 2.75 ft. = 11 sq. ft. ( Max ) <br />Calculate Uplift at each support: <br />Pnet = A lit 1 P net30 Eq'n 30.5-1 ASCE 7-10 <br />A = 1.35 Wind Speed 130 mph Exposure C <br />Kzt = 1.0 <br />I = 1.0 <br />Pneoo = -46.5 psf <br />&! No. C58724 1 58 <br />* Exp. 3-31-15 * <br />d> \ CIV\L ,< <br />Pnet = 1.35 x 1.0 x 1.0 x (-46.5 psf) = -62.8 psf <br />Nominal (Unfactored) Uplift at each support = 62.8 psf x 11 sq. ft. = 691 lbs <br />Note: Section 2.4.1 of ASCE 7- 10, Basic Load Combinations for Allowable Stress <br />Design. Note: Applicable Load Combination #5 (D + 0.6W) <br />Design (Factored) Uplift at each support = 0.6 x 691 lbs = 414 lbs <br />Load per lag screw = 414 lbs /1= 414 lbs <br />Determine allowable load per 5/16" lag screw w/ 2.5" embedment into wood below <br />according to the 2012 NDS. <br />W' =Wx Cd x Ct Table 10.3.1 2012 NDS <br />where: <br />V = 266 lbs / in. of embedment per Table 11.2a <br />,u - 1.U per Table 2.3.2 of 2012 NDS <br />1 = 1.0 per Table 10.3.4 of 2012 NDS <br />V ' = 266 lbs/ in. x 2.5 in. x 1.6 x 1.0 = 1,064 lbs>414 lbs OK <br />Use Support connected to 2x Min. Roof Member <br />w/ (1) 5/16" x 4" lag screws per connection minimum. <br />2014- 755 Nexus Energy Sylvina Cornejo Residence <br />Sht # 4 of 6 <br />Date: May 16, 2014