211 BARBARA LN 2022-04-04 - Laserfiche WebLink

• SO LGEN POWER November 11,2020 Subject: Proposed Solar Panel Installation Georgia Hallett Residence,211 Barbara Lane, Everett,WA 98203 To Whom it May Concern, Our engineering department has reviewed information,gathered by our field crews, related to the proposed solar panel installation at the above-referenced address.The purpose of our review was to determine the structural adequacy of the existing roof for the proposed installation. Based on our review and analysis of the available information, it is our professional opinion that the existing structure is adequate to support the planned solar system. Design Parameter Summary Governing Building Code: 2015 Washington Building Code(2015 IBC) Risk Category: II Design Wind Speed: 110 mph (per ASCE 7-10) Ground Snow Load: 20 psf Roof Information Roof Structure: 2x4 Manufactured Trusses @ 24" O.C. Roofing Material:Asphalt Shingles Roof Slope: 18 degrees Roof Connection Details Lag Screws:5/16" diameter min.,with min. 2.5" embedment into framing members,at 48"O.C. min, staggered Locations per design drawings Note:Required embedment length excludes the tapered tip of the screw,and embedment into sheathing. Analysis The proposed installation - including weight of panels, racking, and mounts -will be approximately 2.43 psf. In the areas where panels are installed, roof live loads will not be present. Also,where applicable, roof snow loads will be reduced because the slippery surface of the panels will cause the roof to shed additional snow loads relative to the existing roof surface. The reduction of roof live and snow load is adequate to fully or partially compensate for the addition of the panel installation. Because the member forces in the area of the solar panels are not increased by more than 5%, the stresses in the members are not increased by more than 5%, and per section 807.4 of the International Existing Building Code(IEBC),the structure need not be altered for gravity loading. ' (2