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McPherson Engineering By:J.R. <br />Date:7/25/24 <br />Rooftop Solar Panels Wind Pressures (Section 29.4, ASCE 7-16) <br />Vult =110 mph Kzt =1.00 (sec 26.8.2)h = 15 ft <br />Exposure Category =C Kz = 0.85 (sec 26.10.1) <br />Roof Zone =2 Kd =0.85 (sec 26.6) <br />Panel θ = 0.0 deg Ke =1.00 (sec 26.9) <br />qh = 0.00256 Kz Kzt Kd Ke V2 qh =22.38 (eq. 26.10-1) <br />γE =1.5 FIG 29.4-7)γc =0.80 (fig 29.4-7)hpt =0 ft <br />γa =0.69 (fig 29.4-8)γp =0.9 (fig 29.4-7)ω =0.00 deg <br />GPp =-2 uplift GCrn =-1.4 uplift <br />p = qh (GPp) γE γa (eq 29.4-7)p = qh (GCrn) γE γC γp (eq 29.4-6) <br />p =-46.6 p.s.f.p =-33.8 p.s.f. <br />Check Anchorage to Existing Structure <br />0.6DL - 0.6W controlling load combination (eq. 16-15 for ASD) <br />DL =2.8 p.s.f.dead load of panel (inlcuding rack system) <br />W = 46.6 p.s.f.wind load normal to face of panel <br />Arealag =18.4 sq. ft.area tributary to each anchor <br />SPanc =6.0 ft.spacing of anchors <br />Puplift = Arealag (0.6DL - 0.6W) =482.8 lbs total uplift on anchor <br />Material =DFL lumber anchor material <br />Dialag =5/16 in.diameter of screw <br />Penlag =2.5 in.min. penetration to existing framing <br />W lag =205 lb/in.withdrawal load per in. of penetration per NDS Table 11.2A <br />CD =1.6 load duration factor for wind per NDS Table 2.3.2 <br />Ct =0.8 temperature factor per NDS Table 2.3.3 <br />Noscrews =1 number of screws in withdrawal <br />Pallow = Penlag (Wlag CD Ct) * Noscrews =656 lbs total allowable withrawal on anchor <br />Puplift <br />Pallow <br />Anchorage =USE (1) 5/16IN. DIA. LAG SCREW(S) AT 6FT. MAX. O.C. W/ 2.5IN. MIN. PENETRATION <br />=0.74 < 1.00 Anchor is OK! <br />Wind Uplift Anchorage <br />Flush Mounted Panels - ASCE Section <br />29.4.4 (where applicable) <br />Flat Roof Panels - ASCE Section 29.4.3 <br />(where applicable) <br />7/25/2024 5:22 PM <br />8 of 9 <br />©McPherson Engineering <br />2415 N Bonnie <br />Brae9/23/2024