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SOLGrzN <br />P O W E R <br />August 17, 2022 <br />Subject: Proposed Solar Panel Installation <br />Jenica Valdivia Residence, 11822 24th Dr SE, Everett, WA <br />To Whom it May Concern, <br />Our engineering department has reviewed information, gathered by our field crews, related to the proposed solar <br />panel installation at the above -referenced address. The purpose of our review was to determine the structural <br />adequacy of the existing roof. Based on our review and analysis of the available information, and in accordance <br />with governing building codes, it is our professional opinion that the existing structure is permitted to remain <br />unaltered for the proposed solar installation. <br />Design Parameter Summary <br />Governing Building Code: 2018 Washington Building Code (2018 IBC) <br />Risk Category: II <br />Design Wind Speed: 110 mph (per ASCE 7-16) <br />Ground Snow Load: 15 psf <br />Roof Information <br />Roof Structure: 2x4 Manufactured Trusses @ 24" O.C. <br />Roofing Material: Asphalt Shingles (1 layer) <br />Roof Slope: 27 degrees <br />Roof Connection Details <br />RT Minis into 2x rafters or truss top chords at 48" O.C., install per design drawings and manufacturer specs <br />Locations per design drawings <br />Note: Required embedment length excludes the tapered tip of the screw, and embedment into sheathing. <br />Analysis <br />The proposed installation - including weight of panels, racking, and mounts - will be approximately 2.77 psf. In the <br />areas where panels are installed, roof live loads will not be present. The reduction of roof live load is adequate to <br />fully or partially compensate for the addition of the panel installation. Because the member forces in the area of <br />the solar panels are not increased by more than 5%, the stresses in the members are not increased by more than <br />5%, and so per section 806.2 of the International Existing Building Code (IEBC), the structure need not be altered for <br />gravity loading. <br />The proposed installation will be 6" max. above the roof surface (flush mounted) and parallel to the roof surface. <br />Therefore, any increase in wind loading on the building structure from the solar panel installation is expected to be <br />negligible. Wind is the governing lateral load case. Because the increase in lateral loading is not increased by more <br />than 10%, per section 806.3 of the adopted IEBC, the structure need not be altered for lateral loading. <br />