Laserfiche WebLink
McPherson Engineering By: A.L. <br />Date: 4/29/22 <br />Rooftop Solar Panels Wind Pressures (Section 29.4, ASCE 7-16) <br />Vult = 130 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 = 7-27 deg Ke = 1.00 (sec 26.9) <br />qh = 0.00256 Kz Kzt Kd Ke V 2 qh = 31.26 (eq. 26.10-1) <br />γE = 1.5 FIG 29.4-7) γc = 0.98 (fig 29.4-7) hpt = 0 ft <br />γa = 0.76 (fig 29.4-8) γ p = 0.9 (fig 29.4-7) ω = 0.00 deg <br />GPp = -2 uplift GCrm = 1.4 uplift <br />p = qh (GPp) γ E γ a (eq 29.4-7) p = qh (GCrn) γ E γC γ p (eq 29.4-6) <br />p = -71.1 p.s.f.p = 58.0 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 = 71.1 p.s.f. wind load normal to face of panel <br />Arealag = 12.7 sq. ft. area tributary to each anchor <br />SPanc = 4.0 ft. spacing of anchors <br />DLPL= 0.0352 kips Point dead load of panel (inlcuding rack system) <br />WPL= 0.905 kips Point wind load normal to face of panel <br />Puplift = Arealag (0.6DL - 0.6W) = 522.0 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 />Wlag = 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 = 1 number of screws in withdrawal <br />Pallow = Penlag (Wlag CD Ct) * Noscrews = 851.2 lbs total allowable withrawal on anchor <br />Puplift <br />Pallow <br />Anchorage = USE (1) 5/16IN. DIA. LAG SCREW(S) AT 4FT. MAX. O.C. W/ 2.5IN. MIN. PENETRATION <br />0.61 < 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 />= <br />4/29/2022 11:04 AM <br />6 of 7 <br />©McPherson Engineering <br />405 W. Alpine Ave <br />- 2017720009/06/22