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By:F.V. <br />Date:1/15/24 <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 />Roof θ = 0-7 deg Ke =1.00 (sec 26.9) <br />qh = 0.00256 Kz Kzt Kd Ke V2 qh =22.38 (eq. 26.10-1) <br />GPp =-2 uplift γE =1.5 (sec 29.4.4) <br />γa =0.61 (fig 29.4-8) <br />γE =1.5 FIG 29.4-7)γc =1.05 (fig 29.4-7)hpt =0 <br />γa =0.61 (fig 29.4-8)γp =0.9 (fig 29.4-7)ω =10.00 deg (panel tilt) <br />GPp =-2 uplift GCrm =2 uplift <br />p = qh (GPp) γE γa (eq 29.4-7)p = qh (GCrn) γE γC γp (eq 29.4-6) <br />p =-40.9 p.s.f.p =63.4 p.s.f. <br />Check Anchorage to Existing Structure <br />0.6DL - 0.6W controlling load combination (eq. 16-15 for ASD) <br />DL =3.0 p.s.f.dead load of panel (inlcuding rack system) <br />W = 63.4 p.s.f.wind load normal to face of panel <br />Arealag =30.0 sq. ft.area tributary to each anchor <br />SPanc =8.0 ft.spacing of anchors <br />Puplift = Arealag (0.6DL - 0.6W) =1087.2 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 =266 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 =2 number of screws in withdrawal <br />Pallow = Penlag (Wlag CD Ct) * Noscrews =1702.4 lbs total allowable withrawal on anchor <br />Puplift <br />Pallow <br />Anchorage =USE (2) 5/16IN. DIA. LAG SCREW(S) AT 8FT. MAX. O.C. W/ 2.5IN. MIN. PENETRATION <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 />=0.64 < 1.00 Anchor is OK! <br />1/15/2024 2:30 PM <br />6 of 7 <br />©McPherson Engineering <br />825 N Parkcenter Dr - <br />101118224 & 201820725/31/2024