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REVIEWED RESUB 1-BLD2024-0502+Structural_Calculations+5.14.2024_9.20.31_AM+4255100REVIEWED BLD2024-0502 RESUB BYMay 14 2024 CITY OF E D M O N DS of �EPaR�EM ES V e e r s Engineer: Trevor Jones Address: 518 Lake Cleveland Street, Burley, ID May 08, 2024 83318 Phone: (208) 994-1680 Subject: Proposed Solar Panel Installation Edmonds United Methodist Church, 828 Caspers Street, Edmonds United Methodist Church, WA PV Letters Job #006-1574 To Whom it May Concern, We have reviewed information, provided by our client, related to the proposed solar panel installation at the above -referenced address. The purpose of the review was to determine if the existing roof is structurally adequate for the proposed installation. Based on our review and analysis of the given information, and in accordance with governing building codes, it is our professional opinion that the existing structure is permitted to remain unaltered for the proposed solar installation. Design Parameter Summary Governing Building Code: 2021 International Residential Code (IRC) Risk Category: II Wind Exposure: C Design Wind Speed: 110 mph Ground Snow Load: 25 psf Roof Information Roof Structure: 2x4 Manufactured Trusses @ 24" O.C. (assumed) Roofing Material: Asphalt Shingles Roof Slope: 14, 18 degrees Roof Connection Details Lag Screws: 1 screw, 5/16" dia min., with min. 2.5" embedment into roof truss top chord only, at 72" O.C. max Stagger attachments to avoid overloading any individual truss top chord. EnEineerine Analysis The proposed installation - including weight of panels, racking, and mounts - will be approximately 2.59 psf. Based on information provided by the client the existing roof is composed of one layer of asphalt shingles. Therefore, according to the International Existing Building Code, Section 806.2, Exception 2, the structure need not be altered for gravity loading. The relevant provision states "buildings in which the increased dead load is attributable to the addition of a second layer of roof covering weighing 3 pounds per square foot (0.1437 Miri2) or less over an existing single layer of roof covering" are excepted from alterations for gravity loading. Additionally, the proposed installation complies with the requirements of WAC Section 51-51-03240 R324.4 (Exception) and is therefore deemed adequate to support the load of the rooftop solar system. See attached calculations. The proposed installation will be 6" max. above the roof surface (flush mounted) and parallel to the roof surface. Therefore, any increase in wind loading on the building structure from the solar panel installation is expected to be negligible. Wind is the governing lateral load case. Because the increase in lateral loading is not increased by more than 10%, per provisions in the adopted building codes, the structure need not be altered for lateral loading. Wind uplift on the panels has been calculated in accordance with the relevant provisions of ASCE 7-16. This loading has been used to verify the adequacy of the connection specified above. Connection locations should be in accordance with design drawings. IronRidge XR100 rails will support the modules and will fasten to the roof structure with IronRidge F1ashFoot2 along the rail. Conclusion The roof structure need not be altered for either gravity loading (including snow) or lateral loading (including wind). Therefore, the existing structure is permitted to remain unaltered. Connections to the roof must be made per the "Roof Connection Details" section above. Copies of all relevant calculations are enclosed. Limitations and Disclaimers The opinion expressed in this letter is made in reliance on the following assumptions: the existing structure is in good condition; the existing structure is free from defects in design or workmanship; and the existing structure was code -compliant at the time of its design and construction. These assumptions have not been independently verified, and we have relied on representations made by our client with respect to the foregoing. The undersigned has not inspected the structure for defects, although we have reviewed the information provided by our client, including pictures where applicable. Electrical design is excluded from this analysis. Waterproofing is the sole responsibility of the installer and is also excluded from this analysis. Solar panels must be installed per manufacturer specifications. Structural design and analysis of the adequacy of solar panels, racks, mounts, and other components is performed by each component's respective manufacturer; the undersigned makes no statement of opinion regarding such components. This letter and the opinions expressed herein are rendered solely for the benefit of the permitting authority (city or county building department) and your office, and may not be utilized or relied on by any other party. if you have any questions or concerns, please contact me at (208)-994-1680, or email me directly at Trevor@pvletters.com. Sincerely, Trevor A. Jones, P.E. 5/8/2024 Pko 0, 91 #7f APV Letters Detailed Loading Comparison (Roof 1) This calculation justifies the additional solar load by comparing existing vertical reactions to proposed reactions, thus showing that stresses will not increase by more than 5%, and therefore the proposed installation is justified. Dead Load Without Solar With Solar Asphalt Shingles Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, CS Sloped Roof Snow Load Live Load 5.0 5.0 1.0 1.0 4.0 4.0 1.0 1.0 2.0 2.0 1.5 1.5 0.0 2.6 14.5 17.1 25 1 1.1 1 19 14 No No 1.00 1.00 19.3 19.3 psf psf psf psf psf psf psf psf psf Eqn. 7.3-1 or jurisdiction min. degrees psf Roof Live Load 1 20 20 psf NOTE: Analysis assumes there is no live load on solar panels Load Combination D + Lr 34.5 37.1 psf D + S 33.8 36.3 psf Member Information Member span Member spacing Solar Array start point Solar Array end point Solar Array weight Reaction 1 Reaction 2 Max. Moment 43.0 2.0 -- 2.4 -- 18.2 -- 2.6 1483.5 1527.9 1483.5 1497.5 15947.6 16232.4 ft ft ft ft psf %a eg of original lbs 102.99% lbs 100.94% lb*ft 101.79% Result: Because the reactions and max. moment are not increased by more than 5%, neither are the stresses in the structural members, and so per the adopted existing building code, the existing roof structure is permitted to remain unaltered. 40PV Letters Lag Screw Calculation (per ASCE 7-16) (Roof 1) This calculation justifies the connection of the solar panels to existing roof members, by showing the connection capacity is equal to or greater than the uplift force demands. Connection Demand Spacing perpendicular to rail, in Roof Angle, degrees Roof Layout Wind Speed, mph Exposure Coefficient, K.- Topographic Factor, Kt Directionality Factor, Kd Elevation Factor, Ke Velocity Pressure qZ, psf Zones: Spacing parallel to rail, in GCp (max) Exposed Panels? (YE = 1.5) Effective Wind Area on each con., ft2 Pressure Equalization Factor, ya Uplift Force, psf Max. Uplift Force / Connection (0.6 WL), lbs Solar Dead Load (0.6 DL). Lbs Max. Uplift Force (0.6 WL - 0.6 DL), lbs Connection Capacity Attachment FTG Attachment location Fastener Type Fastener Diameter, in Embedment Length, in Lumber Species & Grade Nominal Withdrawal Capacity W, lbs # of Screws Load Duration Factor Cd Screw Adj. Withdrawal Cap. W', lbs Attachment FTG Strength with Cd, lbs Max applied load, lbs Max allowable load, lbs 14 Gable 110 .5 1.00 0.85 1.00 24.8 2n, 2r, 2e 3r, 3e 72 72 72 2.00 2.67 3.19 No 17.0 17.0 17.0 0.71 0.71 0.71 35.1 46.9 56.0 357.3 477.4 569.5 26.3 26.3 26.3 331.0 451.1 543.2 IronRidge F1ashFoot2 Framing Lag Screw 0.3125 2.5 DFL #2 (Assumed) 665 1 1.6 1064 1171 543 1064 Compare Adiusted Withdrawal Capacity to ASD Factored Demand Zones: 1 2n, 2r, 2e 3r, 3e O.K. O.K. O.K. 40PV Letters Standard Loading Comparison (Roof 2) This calculation justifies the additional solar load by comparing existing to proposed gravity loads in the location of the solar panels. Dead Load Asphalt Shingles 1/4" Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, P9 Exposure Factor, Cc Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, Cs Sloped Roof Snow Load Live Load Roof Live Load Load Combination D+Lr D+S Max. Load % of original Result: Without Solar With Solar 5 5 1 1 4 4 1 1 2 2 1.5 1.5 0 2.59 psf psf psf psf psf psf psf 14.5 1 17.09 psf 25 1.00 1.1 1 19 18 No No 1.00 1.00 19.3 19.3 psf ASCE 7 Eqn. 7.3-1 or jurisdiction min. degrees psf 20 1 0 psf 34.5 17.1 psf 33.8 36.3 psf 34.5 36.3 psf 105.33% USE OTHER SPREADSHEET 40PV Letters Lag Screw Calculation (per ASCE 7-16) (Roof 2) This calculation justifies the connection of the solar panels to existing roof members, by showing the connection capacity is equal to or greater than the uplift force demands. Connection Demand Spacing perpendicular to rail, in Roof Angle, degrees Roof Layout Wind Speed, mph Exposure Coefficient, K.- Topographic Factor, Kt Directionality Factor, Kd Elevation Factor, Ke Velocity Pressure qZ, psf Zones: Spacing parallel to rail, in GCp (max) Exposed Panels? (YE = 1.5) Effective Wind Area on each con., ft2 Pressure Equalization Factor, ya Uplift Force, psf Max. Uplift Force / Connection (0.6 WL), lbs Solar Dead Load (0.6 DL). Lbs Max. Uplift Force (0.6 WL - 0.6 DL), lbs Connection Capacity Attachment FTG Attachment location Fastener Type Fastener Diameter, in Embedment Length, in Lumber Species & Grade Nominal Withdrawal Capacity W, lbs # of Screws Load Duration Factor Cd Screw Adj. Withdrawal Cap. W', lbs Attachment FTG Strength with Cd, lbs Max applied load, lbs Max allowable load, lbs 18 Gable 110 1.00 0.85 1.00 24.8 2n, 2r, 2e 3r, 3e 72 72 72 2.00 2.67 3.19 No 17.0 17.0 17.0 0.71 0.71 0.71 35.1 46.9 56.0 357.3 477.4 569.5 26.3 26.3 26.3 331.0 451.1 543.2 IronRidge F1ashFoot2 Framing Lag Screw 0.3125 2.5 DFL #2 (Assumed) 665 1 1.6 1064 1171 543 1064 Compare Adiusted Withdrawal Capacity to ASD Factored Demand Zones: 1 2n, 2r, 2e 3r, 3e O.K. O.K. O.K. PV Letters Standard Loading Comparison (Roof 3) This calculation justifies the additional solar load by comparing existing to proposed gravity loads in the location of the solar panels. Dead Load Asphalt Shingles 1/4" Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, Cs Sloped Roof Snow Load Live Load Roof Live Load Load Combination D + Lr D + S Max. Load % of original Result: Without Solar With Solar 5 5 1 1 4 4 1 1 2 2 1.5 1.5 0 2.59 psf psf psf psf psf psf psf 14.5 1 17.09 Ipsf 25 1.00 1.1 1 19 14 No Yes 1.00 0.93 19.3 18.0 psf ASCE 7 Eqn. 7.3-1 or jurisdiction min. degrees psf 20 1 0 psf 34.5 17.1 psf 33.8 35.1 psf 34.5 35.1 Ipsf 101.59% Because the total forces are not increased by more than 5%, per the relevant code provisions stated in the body of the letter, the existing roof structure is permitted to remain unaltered. 40PV Letters Lag Screw Calculation (per ASCE 7-16) (Roof 3) This calculation justifies the connection of the solar panels to existing roof members, by showing the connection capacity is equal to or greater than the uplift force demands. Connection Demand Spacing perpendicular to rail, in Roof Angle, degrees Roof Layout Wind Speed, mph Exposure Coefficient, K.- Topographic Factor, Kt Directionality Factor, Kd Elevation Factor, Ke Velocity Pressure qZ, psf Zones: Spacing parallel to rail, in GCp (max) Exposed Panels? (YE = 1.5) Effective Wind Area on each con., ft2 Pressure Equalization Factor, ya Uplift Force, psf Max. Uplift Force / Connection (0.6 WL), lbs Solar Dead Load (0.6 DL). Lbs Max. Uplift Force (0.6 WL - 0.6 DL), lbs Connection Capacity Attachment FTG Attachment location Fastener Type Fastener Diameter, in Embedment Length, in Lumber Species & Grade Nominal Withdrawal Capacity W, lbs # of Screws Load Duration Factor Cd Screw Adj. Withdrawal Cap. W', lbs Attachment FTG Strength with Cd, lbs Max applied load, lbs Max allowable load, lbs 14 Gable 110 .5 1.00 0.85 1.00 24.8 2n, 2r, 2e 3r, 3e 72 72 72 2.00 2.67 3.19 No 17.0 17.0 17.0 0.71 0.71 0.71 35.1 46.9 56.0 357.3 477.4 569.5 26.3 26.3 26.3 331.0 451.1 543.2 IronRidge F1ashFoot2 Framing Lag Screw 0.3125 2.5 DFL #2 (Assumed) 665 1 1.6 1064 1171 543 1064 Compare Adiusted Withdrawal Capacity to ASD Factored Demand Zones: 1 2n, 2r, 2e 3r, 3e O.K. O.K. O.K. PV Letters Standard Loading Comparison (Roof 4) This calculation justifies the additional solar load by comparing existing to proposed gravity loads in the location of the solar panels. Dead Load Asphalt Shingles 1/4" Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, Cs Sloped Roof Snow Load Live Load Roof Live Load Load Combination D + Lr D + S Max. Load % of original Result: Without Solar With Solar 5 5 1 1 4 4 1 1 2 2 1.5 1.5 0 2.59 psf psf psf psf psf psf psf 14.5 1 17.09 Ipsf 25 1.00 1.1 1 19 18 No Yes 1.00 0.87 19.3 16.7 psf ASCE 7 Eqn. 7.3-1 or jurisdiction min. degrees psf 20 1 0 psf 34.5 17.1 psf 33.8 33.8 psf 34.5 33.8 Ipsf 97.91 % Because the total forces are decreased, per the relevant code provisions stated in the body of the letter, the existing roof structure is permitted to remain unaltered. Pko 0, 91 #7f APV Letters Detailed Loading Comparison (Roof 4) This calculation justifies the additional solar load by comparing existing vertical reactions to proposed reactions, thus showing that stresses will not increase by more than 5%, and therefore the proposed installation is justified. Dead Load Without Solar With Solar Asphalt Shingles Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, CS Sloped Roof Snow Load Live Load 5.0 5.0 1.0 1.0 4.0 4.0 1.0 1.0 2.0 2.0 1.5 1.5 0.0 2.6 14.5 17.1 25 1 1.1 1 18 No Yes 1.00 0.87 19.3 16.7 psf psf psf psf psf psf psf psf psf Eqn. 7.3-1 or jurisdiction min. degrees psf Roof Live Load 1 20 20 psf NOTE: Analysis assumes there is no live load on solar panels Load Combination D + Lr 34.5 37.1 psf D + S 33.8 33.8 psf Member Information Member span Member spacing Solar Array start point Solar Array end point Solar Array weight Reaction 1 Reaction 2 Max. Moment 50.2 2.0 -- 31.1 -- 46.6 -- 2.6 1730.9 1743.8 1730.9 1775.0 21709.4 21976.1 ft ft ft ft psf %a eg of original lbs 100.75% lbs 102.55% lb*ft 101.23% Result: Because the reactions and max. moment are not increased by more than 5%, neither are the stresses in the structural members, and so per the adopted existing building code, the existing roof structure is permitted to remain unaltered. 40PV Letters Lag Screw Calculation (per ASCE 7-16) (Roof 4) This calculation justifies the connection of the solar panels to existing roof members, by showing the connection capacity is equal to or greater than the uplift force demands. Connection Demand Spacing perpendicular to rail, in Roof Angle, degrees Roof Layout Wind Speed, mph Exposure Coefficient, K.- Topographic Factor, Kt Directionality Factor, Kd Elevation Factor, Ke Velocity Pressure qZ, psf Zones: Spacing parallel to rail, in GCp (max) Exposed Panels? (YE = 1.5) Effective Wind Area on each con., ft2 Pressure Equalization Factor, ya Uplift Force, psf Max. Uplift Force / Connection (0.6 WL), lbs Solar Dead Load (0.6 DL). Lbs Max. Uplift Force (0.6 WL - 0.6 DL), lbs Connection Capacity Attachment FTG Attachment location Fastener Type Fastener Diameter, in Embedment Length, in Lumber Species & Grade Nominal Withdrawal Capacity W, lbs # of Screws Load Duration Factor Cd Screw Adj. Withdrawal Cap. W', lbs Attachment FTG Strength with Cd, lbs Max applied load, lbs Max allowable load, lbs 18 Gable 110 1.00 0.85 1.00 24.8 2n, 2r, 2e 3r, 3e 72 72 72 2.00 2.67 3.19 No 17.0 17.0 17.0 0.71 0.71 0.71 35.1 46.9 56.0 357.3 477.4 569.5 26.3 26.3 26.3 331.0 451.1 543.2 IronRidge F1ashFoot2 Framing Lag Screw 0.3125 2.5 DFL #2 (Assumed) 665 1 1.6 1064 1171 543 1064 Compare Adiusted Withdrawal Capacity to ASD Factored Demand Zones: 1 2n, 2r, 2e 3r, 3e O.K. O.K. O.K. PV Letters Standard Loading Comparison (Roof 5) This calculation justifies the additional solar load by comparing existing to proposed gravity loads in the location of the solar panels. Dead Load Asphalt Shingles 1/4" Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, Is Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, Cs Sloped Roof Snow Load Live Load Roof Live Load Load Combination D + Lr D + S Max. Load % of original Result: Without Solar With Solar 5 5 1 1 4 4 1 1 2 2 1.5 1.5 0 2.59 psf psf psf psf psf psf psf 14.5 1 17.09 Ipsf 25 1.00 1.1 1 19 14 No Yes 1.00 0.93 19.3 18.0 psf ASCE 7 Eqn. 7.3-1 or jurisdiction min. degrees psf 20 1 0 psf 34.5 17.1 psf 33.8 35.1 psf 34.5 35.1 Ipsf 101.59% Because the total forces are not increased by more than 5%, per the relevant code provisions stated in the body of the letter, the existing roof structure is permitted to remain unaltered. Pko 0, 91 #7f APV Letters Detailed Loading Comparison (Roof 5) This calculation justifies the additional solar load by comparing existing vertical reactions to proposed reactions, thus showing that stresses will not increase by more than 5%, and therefore the proposed installation is justified. Dead Load Without Solar With Solar Asphalt Shingles Plywood Framing Insulation 1/2" Gypsum Ceiling M,E, & Misc Solar Panel Total Dead Load Snow Load Ground Snow Load, Pg Exposure Factor, Ce Thermal Factor, Ct Importance Factor, IS Flat Roof Snow Load Slope Unobstructed Slippery Surface? Slope Factor, CS Sloped Roof Snow Load Live Load 5.0 5.0 1.0 1.0 4.0 4.0 1.0 1.0 2.0 2.0 1.5 1.5 0.0 2.6 14.5 17.1 25 1 1.1 1 19 14 No Yes 1.00 0.93 19.3 18.0 psf psf psf psf psf psf psf psf psf Eqn. 7.3-1 or jurisdiction min. degrees psf Roof Live Load 1 20 20 psf NOTE: Analysis assumes there is no live load on solar panels Load Combination D + Lr 34.5 37.1 psf D + S 33.8 35.1 psf Member Information Member span Member spacing Solar Array start point Solar Array end point Solar Array weight Reaction 1 Reaction 2 Max. Moment 26.3 2.0 -- 0.7 -- 16.6 -- 2.6 906.3 945.5 906.3 925.5 5952.2 6182.8 ft ft ft ft psf %a eg of original lbs 104.33% lbs 102.12% lb*ft 103.87% Result: Because the reactions and max. moment are not increased by more than 5%, neither are the stresses in the structural members, and so per the adopted existing building code, the existing roof structure is permitted to remain unaltered. 40PV Letters Lag Screw Calculation (per ASCE 7-16) (Roof 5) This calculation justifies the connection of the solar panels to existing roof members, by showing the connection capacity is equal to or greater than the uplift force demands. Connection Demand Spacing perpendicular to rail, in Roof Angle, degrees Roof Layout Wind Speed, mph Exposure Coefficient, K.- Topographic Factor, Kt Directionality Factor, Kd Elevation Factor, Ke Velocity Pressure qZ, psf Zones: Spacing parallel to rail, in GCp (max) Exposed Panels? (YE = 1.5) Effective Wind Area on each con., ft2 Pressure Equalization Factor, ya Uplift Force, psf Max. Uplift Force / Connection (0.6 WL), lbs Solar Dead Load (0.6 DL). Lbs Max. Uplift Force (0.6 WL - 0.6 DL), lbs Connection Capacity Attachment FTG Attachment location Fastener Type Fastener Diameter, in Embedment Length, in Lumber Species & Grade Nominal Withdrawal Capacity W, lbs # of Screws Load Duration Factor Cd Screw Adj. Withdrawal Cap. W', lbs Attachment FTG Strength with Cd, lbs Max applied load, lbs Max allowable load, lbs 14 Gable 110 .5 1.00 0.85 1.00 24.8 2n, 2r, 2e 3r, 3e 72 72 72 2.00 2.67 3.19 No 17.0 17.0 17.0 0.71 0.71 0.71 35.1 46.9 56.0 357.3 477.4 569.5 26.3 26.3 26.3 331.0 451.1 543.2 IronRidge F1ashFoot2 Framing Lag Screw 0.3125 2.5 DFL #2 (Assumed) 665 1 1.6 1064 1171 543 1064 Compare Adiusted Withdrawal Capacity to ASD Factored Demand Zones: 1 2n, 2r, 2e 3r, 3e O.K. O.K. O.K.