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Page 2 of 2 <br />D. Solar Panel Anchorage <br />1. The solar panels shall be mounted in accordance with the most recent Sunmodo installation <br />manual. If during solar panel installation, the roof framing members appear unstable or deflect non - <br />uniformly, our office should be notified before proceeding with the installation. <br />2. The maximum allowable withdrawal force for a 5/16" lag screw is 235 Ibs per inch of penetration as <br />identified in the National Design Standards (NDS) of timber construction specifications. Based on <br />a minimum penetration depth of 2'/", the allowable capacity per connection is greater than the <br />design withdrawal force (demand). Considering the variable factors for the existing roof framing <br />and installation tolerances, the connection using one 5/16" diameter lag screw with a minimum of <br />2'/" embedment will be adequate and will include a sufficient factor of safety. <br />3. Considering the wind speed, roof slopes, size and spacing of framing members, and condition of <br />the roof, the panel supports shall be placed no greater than 48" on center. <br />4. Panel supports connections shall be staggered to distribute load to adjacent framing members. <br />Based on the above evaluation, this office certifies that with the racking and mounting specified, the existing <br />roof system will adequately support the additional loading imposed by the solar system. This evaluation is in <br />conformance with the Washington State Residential Code, current industry standards, and is based on <br />information supplied to us at the time of this report. <br />Should you have any questions regarding the above or if you require further information do not hesitate to <br />contact me. <br />V truly yours, <br />Scott E. Wyssli , PE <br />Washington License 111163 <br />Signed 10/31 /2022 <br />SSLING <br />CONSULTING <br />