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Structural Calculations -Roof Mounted Solar System - 2 arrays April 22,2014 <br />job: Luis Reyes Contractor: Sunpro Solar (Bob Kornmann) <br />2031 South Artesia 34859 Frederick St. Suite 101 <br />Santa Ana, Ca. 92704 * (714) 915-8744 Wildomar, Ca. 92595 * (951) 813-5408 <br />Description: (12) solar panels (217 total sq ft) mounted in (2)arrays on (5) lines, 79 total feet of Sun <br />Frame rails supported by (23) standojfs connected to roofwith (1) lag screw each through roof <br />diaphragm (sealed) and supported by 2 x 4 trusses, 24" dc on south & eastfacingroofs of existing <br />1-story residence with standardflush mount on 3:12 pitch comp roof at job address shown above.Area <br />at bases to be patched with new roofsealant per Professional Solar Products installation instructions. <br />Page 4 <br />Sun Frame rails, L=4'(allowable load/ft = 200 plj) <br />Maximum tributary area/ft to rails 4.33' @ 2.27 panel psf (411b panels/18.08 sq ft ofpanel) <br />plfofrails 1.13 plf <br />trib load 9.83 plf <br />Wind load 29.53 (7.02 psfx 4.33' x cos 14 degrees) <br />Rail load 40.49 plf with wind < 200 x 1.6 plf-OK <br />Sun Frame rails as shown in this design are very safe (conservative) <br />Check Trusses: <br />Exist Loads: 3:12 (1.03 DL)Max Proposed Loads 3:12(1.03 DL) <br />2 x 4 Trusses @ 24" c/c 1.8 psf 2 x 4 Trusses @ 24" c/c 1.8 psf <br />Insulation 0.5 Insulation 0.5 <br />5/8: Drywall Ceiling 2.1 5/8: Drywall Ceiling 2.1 <br />!6" plywood 1.5 14" plywood 1.5 <br />301b felt 0.4 301b felt 0.4 <br />Composition shingle 3.1 nsf Solar Panel system w/ wind dn load 2.8 <br />Dead load 9.4 psf Composition shingle 3.1 psf <br />Live load 20.0 psf Dead load 12.2 psf <br />Total Load *29.4 psf Live load * *00.0 psf <br />Wind down load 7.3 psf <br />Total Load *19.5 psf <br />* TL allowable 40 psf <br />** Live load = 20 psfat open roof (no solar panels) but not combined with wind down load <br />Top chord loading: 6.2 psfDL (existing uniform) andpoint loading (see page 5) <br />The existing trusses are designed for 20 psf dead load and 20 psf live load. The <br />dead load proposed is 12.2 psf and the proposed live load is 0 psf where the panels are located. <br />Therefore, the existing trusses may handle the addition of the solar panel system: <br />395 lb/141 sq ft + 7.28 psf wind down load. (10.08 p€ftotal). Thiswould-he true even if there were <br />still a 20 psf live load in addition to the wind over the solar-panels, which iknot required; besides <br />this, walking on the installed panels is not allowed.03;4078ore, tl safe design. <br />¢ e 22.- 14.-Lawrence R. Phelps, RGE'Calif. Lic. Ren 115 <br />31130 Avenidaz64'Reposo, Temecula, California 92591 <br />Cell/voice (951) 297-0555 - Office/voice (951) 694-6336