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Domus Domus Structural Engineering, LLC <br /> S T R U C; T U R A 1, P.O. Box 560 <br /> Broomfield, CO 80038 <br /> ENGTNEER ING 1, LC 530-864-7055 <br /> projects@domusstruc.com <br /> September 14,2023 <br /> To: Blue Raven Solar <br /> 1403 North Research Way,Building J <br /> Orem,UT.84097 <br /> Subject: Certification Letter <br /> Taft-Farren Residence <br /> 7205 7th Dr W <br /> Everett,WA.98203 <br /> To Whom It May Concern, <br /> A jobsite observation of the condition of the existing framing system was performed by an audit team of Blue Raven Solar as a <br /> request from Domus Structural Engineering.All review is based on these observations and the design criteria listed below and <br /> only deemed valid if provided information is true and accurate. <br /> On the above referenced project,the roof structural framing has been reviewed for additional loading due to the installation of <br /> the solar PV addition to the roof.The structural review only applies to the section of the roof that is directly supporting the solar <br /> PV system and its supporting elements.The observed roof framing is described below.If field conditions differ,contractor to <br /> notify engineer prior to starting construction. <br /> The roof structure of(MP1)consists of composition shingle on roof plywood that is supported by pre-manufactured trusses that <br /> are spaced at @ 24"o.c..The top chords,sloped at 24 degrees,are 2x6 sections,the bottom chords are 2x6 sections and the web <br /> members are 2x4 sections.The truss members are connected by steel gusset plates.The max unsupported projected horizontal <br /> top chord span is approximately 8'-0". <br /> The existing roof framing system of(MP1)is judged to be adequate to withstand the loading imposed by the installation of the <br /> solar panels.No reinforcement is necessary. <br /> The spacing of the solar standoffs should be kept at 72"o.c.for landscape and 48"o.c.for portrait orientation,with a staggered <br /> pattern to ensure proper distribution of loads. <br /> The scope of this report is strictly limited to an evaluation of the fastener attachment,underlying framing and supporting <br /> structure only.The attachment's to the existing structure are required to be in a staggered pattern to ensure proper distribution <br /> of loading.All panels,racking and hardware shall be installed per manufacturer specifications and within specified design <br /> limitations.All waterproofing shall be provided by the manufacturer. Domus Structural Engineering assumes no responsibility <br /> for misuse or improper installation of the solar PV panels or racking. <br /> Design Criteria: A• Col <br /> ti <br /> • Applicable Codes=2015 IBC/IRC,ASCE 7-10 <br /> • Roof Dead Load=8 psf(MP1) <br /> • Roof Live Load=20 psf <br /> • Wind Speed=110 mph(Vult),Exposure C,Risk Category II <br /> • Roof Snow Load=25 psf <br /> • Attachment:1-5/16 dia.lag screw with 2.5 inch min.embedment <br /> depth,at spacing shown above. h � 46056 <br /> Please contact me with any further questions or concerns regarding this project. SS�OIvq< r'` <br /> Sincerely, Digitally signed by <br /> John A. Calvert <br /> John Calvert,P.E. Date: 2023.09.14 <br /> Project Engineer <br /> 15:01 :31 -06'00' <br /> Taft-Farren Everett WA 1 <br />