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Barun Corp I Design and Engineering I 610.202.4506 I chrisk@baruncorp.com I www.baruncorp.com <br /> <br />February 11, 2023 <br /> <br />GAF Energy <br />5981 Optical Court <br />San Jose, CA 95138 <br /> <br />ATTN: GAF Energy – Engineering Department <br />Barun Corp – Structural Engineering Team has reviewed the Timberline Solar ES Tech Specs. Based <br />on the information provided, the Timberline Solar ES product weighs 10 lbs per energy shingle. The <br />shingle size is 17.125 in x 63.8 in. The weight of the product is therefore, 1.32 lbs/sq ft (psf). Provided <br />that most residential roofs have a typical asphalt comp shingle roof with weight ranges between 2 psf <br />and 4 psf per layer, it is my opinion that the installation of the Timberline Solar ES Product will meet the <br />2022 California Existing Building Code Section 502.4 captured below. <br />502.4 Existing Structural Elements Carrying Gravity Load <br />Any existing gravity load-carrying structural element for which an addition and its related alterations <br />cause an increase in design dead, live or snow load, including snow drift effects, of more than 5 percent <br />shall be replaced or altered as needed to carry the gravity loads required by the California Building <br />Code for new structures. <br /> <br />Sample Calculation: <br />Existing Condition New Condition <br />Roofing (Asphalt Comp Shing) 1 Layer: 2.5 psf <br />Underlayment: 0.5 psf <br />Sheathing: 1.5 psf <br />Framing (2x4 @ 24” O.C. assumed): 1.0 psf <br />Miscellaneous: 1.5 psf <br />Timberline Solar ES: 1.32 psf <br />Underlayment: 0.5 psf <br />Sheathing: 1.5 psf <br />Framing (2x4 @ 24” O.C. assumed): 1.0 psf <br />Miscellaneous: 1.5 psf <br />Total Roof Dead Load: 7.0 psf Total Roof Dead Load: 5.82 psf <br /> <br />Load Increase = 5.82 psf / 7.0 psf = 0.83% < 1.05%. Hence, compliant with 2022 CEBC 502.4 <br /> <br />Please feel free to contact us with any questions or concerns. <br />Prepared by: <br /> <br />Structural Engineering Team <br />