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Home My WebLink About1010 Pulitzer Rd - Solar PV PlansGODWIN ENGINEERING AND DESIGN, LLC 8378 Foxtail Loop, Pensacola, FL 32526 | (850)712-4219 | chad@godwineng.com April 5, 2021 To: St. Lucie County Building Division 2300 Virginia Avenue Ft. Pierce, FL 34982 Re: Lane – Residential PV Roof Mount Installation 1010 Pulitzer Rd. Fort Pierce, FL 34945 Plan Reviewer, This letter is regarding the installation of a new roof mounted Solar PV System on the existing residential structure at the address above. I have reviewed the attachment plan and have determined that the roof mounted PV system is in compliance with the applicable sections of the following Codes as amended and adopted by the jurisdiction: 2020 Florida Building Code 7th Edition, FBC ASCE 7 Min. Design Loads for Buildings & Other Structures Per 2020 FBC, the Roof Mounted PV system will be subject to the following design criteria: Design Wind Speed(Vult) - 160mph 3sec gust, Exposure Category – C The PV System consist of the modules, railing, and connection hardware. The system will add a dead load of approximately 3 psf to the roof. The existing roof covering is Asphalt Shingle with min. ½” plywood decking and 2” x 4” roof trusses 24” O.C. The roofing, decking, and roof trusses are in good condition. The existing structure will be adequate for supporting the additional PV dead load and wind loads. The securement method of the PV system is to be flush mounted to the asphalt shingle roof with the Ironridge railing and flashings/attachments. In R1-R5, the attachments can be attached up to 48” apart in roof zone 1, and 24” apart in roof zones 2e, 2r, & 3. In R6, the attachments can be attached up to 48” apart in roof zones 1, 2e, 2n, 2r, 3e, and 24” apart in roof zone 3r. The mounts should be staggered, where possible, to allow distribution of the design loads evenly to the structure. The mounts shall be installed with a min. 5/16” lag screw with minimum 2-5/16” thread length. Please see attached documents and contact me should you have any questions. Sincerely, D. Chad Godwin, PE 81360 Exp. 02/28/2023 Risk Category II Table 1.5‐1 Load, PSf Basic Wind Speed (Ult) 160 Figure 26.5‐1B 3 Wind Speed (asd) 124 IBC 1609.3.1 0 Roof Angle 20 °0 Effective Wind Area 18.36 ft2 26.20 n/a Wind Load Parameters n/a Wind Directionality Kd 0.85 Table 26.6‐1 n/a Exposure Cat. B,C, or D C Section 26.7 n/a Topographic factor Kzt 1.00 26.8 or 26.8.2 n/a Ground Elevation Factor Ke 1.00 Table 26.9‐1 n/a Velocity Exposure Coefficient Kz 0.85 Table 30.3‐10 Array Edge Factor gE 1.50 29.4.4 *Modules are considered Exposed n/a Solar Panel Equalization Factor ga 0.69 Fig. 29.4‐8 see calc Velocity Pressure qp 28.41 psf qh=0.00256 KzKztKdKeV2 n/a Mean Roof Height h 20.00 ft h2 5inNot > 10in(height above roof) 0.4h 8.00 ft 2h2 10 in *min distance array shall be from the roof edge, Gable Ridge, or hip ridge 398 in 0.25 in min gap between all panels but not > 6.7ft 3.32 ft d1 1.00 ft Horizontal distance orthogonal to panel edge Roof Zone Set Back a 3.32 ft d2 0.25 ft Horizontal distance from edge of one panel to the nearest edge in the next row h/B 0.60 0.5h 10.00 ft 1.5Lp 8.37 ft 12r2e3 GCp ‐1.30 ‐1.80 ‐1.80 ‐1.80 uplift GCp 0.70 0.70 0.70 0.70 downward p = qh(GCp)(gE)(γa)‐38.47 ‐53.27 ‐53.27 ‐53.27 psf uplift p = qh(GCp)(gE)(γa)20.72 20.72 20.72 20.72 psf downward Module Length C(Lp)ft Module Width B ft Module Area A ft2 Total Design Load (Uplift)Pdesign ‐38.47 ‐53.27 ‐53.27 ‐53.27 psf Total Design Load (Downforce)Pdesign 20.72 20.72 20.72 20.72 psf Design Load per Module Tup ‐706.29 ‐977.95 ‐977.95 ‐977.95 lbs Tup = A * Pdesign Design Load per Module Tdown 380.31 380.31 380.31 380.31 lbs Tdn = A * Pdesign Distributed Load (Uplift)Pdist. Up ‐107.34 ‐148.62 ‐148.62 ‐148.62 plf Tup / B*2 Distributed Load (Down)Pdist. Down 57.80 57.80 57.80 57.80 plf Tdn / B*2 Railspan Between Anchor Points L 4 2 2 2 ft Point Load per Mount (Uplift) R ‐429.36 ‐297.25 ‐297.25 ‐297.25 lbs Point Load per Mount (Down) R 115.60 57.80 57.80 57.80 lbs Specific Gravity G 0.55 0.55 0.55 0.55 Table 11.2A, NDS 2005, page 68 (SYP) Diameter of Lag Screw D 5/16 5/16 5/16 5/16 In Pullout Value of W 306.8697 306.8697 306.8697 306.8697 lbs/in W=1800 G3/2 D3/4 # of Lag screws 1111 Thread Length Td 2.8 2.8 2.8 2.8 In Table L2, NDS 2005 Design Pullout Value per Mount Wt 859.2353 859.2353 859.2353 859.2353 Wt = W * # of Lags *Td SAFTEY FACTOR SF 2.00 2.89 2.89 2.89 Calculation: SF=Wt/R (Uplift) 12r2e3 Max Cantilever M 16 8 8 8 in Max rail span * 33% Snow, S Self‐Straining, T Wind, W Wind‐on‐Ice, Wi ASCE 7‐16 CHAPTER 29 WIND LOADS ‐ Rooftop Solar Panels Minimum Design Loads ‐ Part 1: Enclosed(Hip, h<60ft, 20°<θ<27°) Load Types Dead Load, D Weight of Ice, Di Rain, R Earthquake, E Fluid, F Roof Live, Lr Flood Load, Fa Lateral Earth psi, H Live Load, L Maximum Cantilever from Last attachment Table 1.1 ‐ Pullout Value for Single Lag Screw 10% of least horizontal dim least horizontal dim 5.58 3.29 18.36 Figure 30.3‐2G(Hip roof, h<60ft, 20°<θ<27°) Zone Design Calculations for the Use of Attachment to Roof Truss/Rafter Risk Category II Table 1.5‐1 Load, PSf Basic Wind Speed (Ult) 160 mph Figure 26.5‐1B 3 Wind Speed (asd) 124 mph IBC 1609.3.1 0 Roof Angle 28 °0 Effective Wind Area 18.36 ft2 26.20 n/a Wind Load Parameters n/a Wind Directionality Kd 0.85 Table 26.6‐1 n/a Exposure Cat. B,C, or DC Section 26.7 n/a Topographic factor Kzt 1.00 26.8 or 26.8.2 n/a Ground Elevation Factor Ke 1.00 Table 26.9‐1 n/a Velocity Exposure Coefficient Kz 0.85 Table 26.10‐1 0 Array Edge Factor gE 1.50 29.4.4 *Modules are considered Exposed n/a Solar Panel Equalization Factor ga 0.69 Fig. 29.4‐8 see calc Velocity Pressure qp 28.41 psf qh=0.00256 KzKztKdKeV2 n/a Mean Roof Height h 20.00 ft h2 5inNot > 10in(height above roof) 0.4h 8.00 ft 2h2 10 in *min distance array shall be from the roof edge, Gable Ridge, or hip ridge 398 in 0.25 in min gap between all panels but not > 6.7ft 3.32 ft d1 1.00 ft Horizontal distance orthogonal to panel edge Roof Zone Set Back a 3.32 ft d2 0.25 ft Horizontal distance from edge of one panel to the nearest edge in the next row 0.5h 10.00 ft 1.5Lp 8.37 ft 12e2r2n3e3r GCp ‐1.50 ‐1.50 ‐1.50 ‐1.80 ‐1.80 ‐2.20 uplift GCp 0.90 0.90 0.90 0.90 0.90 0.90 downward p = qh(GCp)(gE)(γa)‐44.39 ‐44.39 ‐44.39 ‐53.27 ‐53.27 ‐65.11 psf uplift p = qh(GCp)(gE)(γa)26.64 26.64 26.64 26.64 26.64 26.64 psf downward Module Length C(Lp)ft Module Width B ft Module Area A ft2 Total Design Load (Uplift)Pdesign ‐41.39 ‐41.39 ‐41.39 ‐50.27 ‐50.27 ‐62.11 psf Total Design Load (Downforce)Pdesign 29.64 29.64 29.64 29.64 29.64 29.64 psf Design Load per Module Tup ‐759.88 ‐759.88 ‐759.88 ‐922.87 ‐922.87 ‐1140.19 lbs Tup = A * Pdesign Design Load per Module Tdown 544.05 544.05 544.05 544.05 544.05 544.05 lbs Tdn = A * Pdesign Distributed Load (Uplift)Pdist. Up ‐115.48 ‐115.48 ‐115.48 ‐140.25 ‐140.25 ‐173.28 plf Tup / (B*2) Distributed Load (Down)Pdist. Down 82.68 82.68 82.68 82.68 82.68 82.68 plf Tdn / (B*2) Railspan Between Anchor PointsL 444442ft Point Load per Mount (Uplift) R ‐461.93 ‐461.93 ‐461.93 ‐561.02 ‐561.02 ‐346.56 lbs Point Load per Mount (Down) R 165.36 165.36 165.36 165.36 165.36 82.68 lbs Specific Gravity G 0.55 0.55 0.55 0.55 0.55 0.55 Table 11.2A, NDS 2005, page 68 (SYP) Diameter of Lag Screw D 5/16 5/16 5/16 5/16 5/16 5/16 In Pullout Value of W 306.8697 306.8697 306.8697 306.8697 306.8697 306.8697 lbs/in W=1800 G3/2 D3/4 # of Lag screws 111111 Thread Length Td 2.8 2.8 2.8 2.8 2.8 2.8 In Table L2, NDS 2005 Design Pullout Value per Mount Wt 859.2353 859.2353 859.2353 859.2353 859.2353 859.2353 Wt = W * # of Lags *Td SAFTEY FACTOR SF 1.86 1.86 1.86 1.53 1.53 2.48 Calculation: SF=Wt/R (Uplift) 12e2n2r3e3r Max Cantilever M 16 16 16 16 16 8 in Max rail span * 33% Figure 30.3‐2C(Gable roof, h<60ft, 27°<θ<45°) Flood Load, Fa Lateral Earth psi, H Live Load, L Roof Live, Lr Rain, R Snow, S Self‐Straining, T Wind, W Wind‐on‐Ice, Wi least horizontal dim 10% of least horizontal dim Fluid, F Maximum Cantilever from Last attachment ASCE 7‐16 CHAPTER 29 WIND LOADS ‐ Rooftop Solar Panels Minimum Design Loads ‐ Part 1: Enclosed(gable, h<60ft, 27°<θ<45°) Load Types Dead Load, D Weight of Ice, Di Earthquake, E Pullout Value for Single Lag Screw 3.29 5.58 Zone 18.36 Design Calculations for the Use of Attachment to Roof Truss/Rafter