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Standard Loading Comparison <br />Without Solar With Solar <br />Dead Load <br />Asphalt Shingles 5 5 psf <br />1/4" Plywood 1 1 psf <br />Framing 2 2 psf <br />Insulation ---- psf <br />1/2" Gypsum Ceiling ---- psf <br />M,E, & Misc ---- psf <br />Solar Panel 0 3 psf <br />Total Dead Load 8 11 psf <br />Snow Load <br />Ground Snow Load, Pg psf <br />Exposure Factor, Ce <br />Thermal Factor, Ct <br />Importance Factor, Is <br />Flat Roof Snow Load ASCE 7 Eqn. 7.3-1 or jurisdiction min. <br />Slope degrees <br />Unobstructed Slippery Surface?No No <br />Slope Factor, Cs 1.00 1.00 <br />Sloped Roof Snow Load 7.7 7.7 psf <br />Live Load <br />Roof Live Load 20 0 psf <br />Load Combination <br />D + Lr 28.0 11.0 psf <br />D + S 15.7 18.7 psf <br />Max. Load 28.0 18.7 psf <br />% of original 66.79% <br />Result: <br />This calculation justifies the additional solar load by comparing existing to proposed gravity loads <br />in the location of the solar panels. <br />Because the total forces are decreased, per the relevant code <br />provisions stated in the body of the letter, the existing roof <br />structure is permitted to remain unaltered. <br />10 <br />1.1 <br />18 <br />1 <br />1.00 <br />8 <br />5402 W Lehnhardt <br />Ave11/25/2024