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<br />AHZ Consulting Engineers, Inc. <br />111 Rodeo <br />Irvine, CA 92602 <br />(949) 466-1544 <br />Date: 07/13/2025 <br /> Job Code: 25035 <br />South Coast Tech <br />Page 3 of 20 <br /> <br /> <br />Roof Check <br /> <br />Methodology <br />The increased weight due to the ballast installation is reported in the table below. A maximum <br />uniform load of 6.21 psf is conservatively assumed for the ballast system and the existing roof <br />structure is evaluated. Ballast weight is evenly distributed on the roof members. <br />The following calculations show the increased load due to ballast installation is less than 5% of <br />gravity design loads and is less than 10% of the seismic design weight for the lateral load <br />calculation. Therefore, no further calculation is required, and the existing roof structure has <br />adequate capacity to resist the ballast-installed load. <br /> <br />PV load (psf) = 6.21 <br />Area of solar panels (sqft) = 3347 <br />Total weight (lbs) = 20782 <br /> Existing roof loads Gravity Check: Dead (psf)= 10 <br />Live (psf) = 20 <br />Snow (psf) = 0 <br /> Load pre-PV D (psf) = 10 <br />D + L (psf) = 30 <br />D + S (psf) = 10 <br />D + 0.75 L + 0.75 S (psf) = 25 <br />Governing load (psf) = 30 <br /> Load post-PV D (psf) = 16.21 <br />D + L (psf) = 26.21 <br />D + S (psf) = 16.21 <br />Governing load (psf) = 26.21 <br /> Gravity load increase Load_postPV / Load_prePV = 0.87 OK <br /> <br />