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Report (2) . _ MS72o22 -ec2.22 8)26)6-cm/ 4le/zi--o c,1 !-1c/ VECTOR )11 Er) G I n E E R s AIL 13 2'320 CITY OF Tlt a 9 VSE Project Number:U3054.0209.201 Ujl ®III ul�Ibi�� June 19,2020 �j 1 Solar ATTENTION:Ty Church 2391 South 1560 West Woods Cross,UT 84087 REFERENCE: Joe Harper Residence: 8205 Southwest Norfolk Lane,Tigard,OR 97224 Solar Array Installation To Whom It May Concern: Per your request, we have reviewed the existing structure at the above referenced site. The purpose of our review was to determine the adequacy of the existing structure to support the proposed installation of solar panels on the roof as shown on the panel layout plan. Based upon our review,we conclude that the existing structure is adequate to support the proposed solar panel installation. Design Parameters Code:Oregon Structural Specialty Code,2019 Edition(2018 IBC) Risk Category: II Design wind speed: 120 mph (3-sec gust)per ASCE 7-16 Wind exposure category:B Design snow load on roof:20 psf Seismic design category:D Existing Roof Structure Roof structure:2x4 manufactured trusses G 24"O.C. Roofing material:composite shingles Roof slope:22.6° Connection to Roof Mounting connection: (1)5/16" lag screw w/min.2.5"embedment into framing at max.48"o.c. along rails (2)rails per row of panels,evenly spaced;panel length perpendicular to the rails not to exceed 67 in Conclusions Based upon our review,we conclude that the existing structure is adequate to support the proposed solar panel installation. The gravity loads, and thus the stresses of the structural elements, in the area of the solar array are either decreased or increased by no more than 5%. Therefore, the requirements of Section 806.2 of the 2018 IEBC as amended by Section 3408.6 of the 2019 OSSC are met and the structure is permitted to remain unaltered. 6S1 W.Galena Park Blvd.,Ste. 101/Draper,UT 84020/T(801)990-1775/F(801)990-1776/www.vectorse.com VSE Project Number: U3054.0209.201 O Joe Harper Residence 6/18/2020 E n G I fl E E R S The solar array will be flush-mounted (no more than 6" above the roof surface) and parallel to the roof surface. Thus, we conclude that any additional wind loading on the structure related to the addition of the proposed solar array is negligible. The attached calculations verify the capacity of the connections of the solar array to the existing roof against wind (uplift), the governing load case. Regarding seismic loads, we conclude that any additional forces will be small. Conservatively neglecting the weight of existing wall materials, the installation of the solar panels represents an increase in the total weight (and resulting seismic load) of 7.3%. Because the increase in lateral forces is less than 10%, this addition meets the requirements of the exception in Section 806.3 of the 2018 IEBC.Thus the existing lateral force resisting system is permitted to remain unaltered. Limitations Installation of the solar panels must be performed in accordance with manufacturer recommendations. All work performed must be in accordance with accepted industry-wide methods and applicable safety standards. The contractor must notify Vector Structural Engineering, LLC should any damage,deterioration or discrepancies between the as-built condition of the structure and the condition described in this letter be found. Connections to existing roof framing must be staggered, except at array ends, so as not to overload any existing structural member. The use of solar panel support span tables provided by others is allowed only where the building type, site conditions, site-specific design parameters, and solar panel configuration match the description of the span tables. The design of the solar panel racking(mounts,rails, etc.)and electrical engineering is the responsibility of others. Waterproofing around the roof penetrations is the responsibility of others. Vector Structural Engineering assumes no responsibility for improper installation of the solar array. VECTOR STRUCTURAL ENGINEERING,LLC Wells ,° Poi- \ IN FRs/ 9 Holmes r 93806PE Digitally signed by Digitally Signed OREGON Wells Holmes Date: 2020.06.19 �`4e ��2Y 10, 2°�� 13:28:27 -06'00' 1 l ND �� EXPIRES: 6/30/2021 06/19/2020 Wells Holmes,S.E. Project Engineer Enclosures WLH/ych 651 W.Galena Park Blvd.,Ste. 101/Draper, UT 84020/T(801)990-1775/F(801)990-1776/www.vectorse.com U305 JOB NO.: WIND 0RESS 1 SUBJECT: WIND PRESSURE E n G I n E E R S PROJECT: Joe Harper Residence Components and Cladding Wind Calculations Label: Solar Panel Array Note: Calculations per ASCE 7-16 SITE-SPECIFIC WIND PARAMETERS: Basic Wind Speed [mph]; 120 Notes: Exposure Category: B Risk Category: II ADDITIONAL INPUT & CALCULATIONS: Height of Roof, h [ft]: 15 (Approximate) Comp/Cladding Location: Gable Roofs 20°<0 5 27° Enclosure Classification: Enclosed Buildings Zone 1, 2e GCp: 1.5 Figure 30.3-2C (enter negative pressure coefficients) Zone 2n, 2r, 3e GCp: 2.5 Zone 3r GCp: 3.6 a: 7 Table 26.11-1 zg [ft]: 1200 Table 26.11-1 Kn: 0.57 Table 26.10-1 Ke: 0.99 Table 26.9-1 Kzr 1 Equation 26.8-1 Kd: 0.85 Table 26.6-1 Velocity Pressure, qt, [psf]: 17.9 Equation 26.10-1 PRESSURES: p = qh (GCp)(yE)(ya) Equation 29.4-5 Zone 1, 2e, p [psf]: 32.2 psf(1.0 W) Zone 2n, 2r, 3e, p [psf]: 53.6 psf(1.0 W) Zone 3r, p [psf]: 77.2 psf(1.0 W) (a = 4.5 ft) V ECr 0 R E rl G I n E E R S JOB NO.: U3054.0209.201 SUBJECT: CONNECTION PROJECT: Joe Harper Residence Calculate Uplift Forces on Connection Pressure Max Connection Max Trib. Max Uplift (0.6 Wind) Spacing Area2 Force (psf) (ft) (ft2) (Ibs) Zone 1, 2e 19.3 4.0 11.2 216 Zone 2n, 2r, 3e 32.2 4.0 11.2 359 Zone 3r 46.3 4.0 11.2 430 Calculate Connection Capacity Lag Screw Size [in]: 5/16 Cd: 1.6 NDS Table 2.3.2 Embedment3 [in]: 2.5 Grade: SPF (G = 0.42) Nominal Capacity [Ibs/in]: 205 NDS Table 12.2A Number of Screws: 1 Prying Coefficient: 1.4 Total Capacity [Ibs]: 586 Determine Result Maximum Demand [Ibs]: 430 Lag Screw Capacity [Ibs]: 586 Result: Capacity> Demand, Connection is adequate. Notes 1. 'Max Connection Spacing' is the spacing between connections along the rails. 2. 'Max Trib Area' is the product of the 'Max Connection Spacing'and 1/2 the panel width/height perpendicular to the rails. (2) rails per row of panels. Length or panels perpindicular to the rails shall not exceed 67". 3. Embedment is measured from the top of the framing member to the beginning of the tapered tip of the lag screw. Embedment in sheathing or other material is not effective.The length of the tapered tip is not part of the embedment length. U3054. VECTOR JOB NO.: GRAVITY LOADS 1 SUBJECT: GRAVITY LOADS E n G i n E E R 9 PROJECT: Joe Harper Residence CALCULATE ESTIMATED GRAVITY LOADS Roof Pitch: 5.0 :12 Design material Increase due to Material weight ROOF DEAD LOAD (D) weight [psf] pitch [psf] Composite Shingles 2.2 1.08 2.0 1/2" Plywood 1.1 1.08 1.0 Framing 3.0 3.0 Insulation 0.5 0.5 1/2" Gypsum Clg. 2.2 1.08 2.0 M, E & Misc 1.5 1.5 Total Original Roof DL 10.4 PV Array DL 3.3 1.08 3 ROOF LIVE LOAD (Lr) Existing Design Roof Live Load [psf] 20 ASCE 7-16, Table 4-1 Roof Live Load With PV Array [psf] 0 2019 OSSC, Section 1607.13.5 SNOW LOAD (S): Existing w/ Solar Array Roof Slope [x:12]: 5.0 5.0 Roof Slope [°]: 23 23 Snow Ground Load, pg [psf]: 10 10 ASCE 7-16, Section 7.2 Terrain Category: B B ASCE 7-16, Table 7-2 Exposure of Roof: Fully Exposed Fully Exposed ASCE 7-16, Table 7-2 Exposure Factor, Ce: 0.9 0.9 ASCE 7-16, Table 7-2 Thermal Factor, CI: 1.1 1.1 ASCE 7-16, Table 7-3 Risk Category: II II ASCE 7-16, Table 1-1 Importance Factor, Is: 1.0 1.0 ASCE 7-16,Table 7-4 Flat Roof Snow Load, pf[psf]: 7 7 ASCE 7-16, Equation 7-1 Minimum Roof Snow Load, pm [psf]: 20 20 ASCE 7-16, Section 7.3.4 Unobstructed Slippery Surface? No No ASCE 7-16, Section 7.4 Slope Factor Figure: Figure 7-2b Figure 7-2b ASCE 7-16, Section 7.4 Roof Slope Factor, Cs: 1.00 1.00 ASCE 7-16, Figure 7-2 Sloped Roof Snow Load, ps [psf]: 7 7 ASCE 7-16, Equation 7-2 Design Snow Load, S [psf]: 20 20 NIECTOR JOB NO.: U3054.0209.201 SUBJECT: MEMBER FORCES E 11 G I 11 E E R S PROJECT: Joe Harper Residence DESIGN LOADS FPSFI: Load Types: Snow Live Dead (D+S)/Cd (D+Lr)/Cd Max Load Existing Roof 20 20 10 26 24 26 Proposed PV Array 20 0 13 29 15 29 (Cd=Load Duration Factor=0.9 for D, 1.15 for S,and 1.25 for Lr) Label manufactured trusses Length 44.75 Existing Proposed Check M (ft-lb) 13242 13557 102% OK Existing Proposed Check V(lb) 1184 1241 105% OK The gravity loads,and thus the stresses of the structural elements,in the area of the solar array are either decreased or increased by no more than 5%.Therefore,the requirements of Section 806.2 of the 2018 IEBC as amended by Section 3408.6 of the 2019 OSSC are met and the structure is permitted to remain unaltered. Existing Loads (Distributed) LOAD(LB) Add'I Add'I 80 - —EXISTING —PROPOSED Live Dead Roof Load Load Bm wt 60 - I I Cond Trib(ft) (plf) (plf) (pif) wu(plf) woL(pIf) 40 - 1 2.00 0 0 0 34.8 18.1 20 - Proposed Loads(Distributed) 0 . — 0 10 20 30 40 50 Dist to Length Load 'a' of Load A wLL SHEAR(LB) Cond (ft) 'b' (ft) (plf) A wog(plf) 2000 1 2 0.0 11.0 0.0 5.2 —EXISTING PROPOSED 3 33.8 11.0 0.0 5.2 1000 4 .#,., 0 5 0 10 20 40 50 6 -1000 Proposed Loads as Point Loads -2000 Point Point MOMENT(FT-LB) Live Dead 15000 Dist'a' Load Load ---EXI —PROPOSED Cond (It) 'PLC'(lb) 'PDL' (lb) 7 10000 8 5000 9 10 0 11 0 10 20 30 40 50