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iRoofTM by Princeton Engineering 009675-0040-1630590018-7060.David Farrell MA sCopyright © 2020 Richard Pantel. All Rights Reserved. Paper or PDF copies of this report may be distributed only to employees of the company listed below under "Prepared for", or to Authorities Having Jursidiction (AHJ's) for their review purposes. This document contains Intellectual Property (IP) created by the Author, and as such, no parts of this calculation report or related data input form(s) may be copied in format, content or intent without permission in writing from the Author. Dis-assembly or reverse engineering of this calculation report or related data input form is strictly prohibited. The Author's contact information is: RPantel@Princeton-Engineering.com, web-site: www.Princeton-Engineering.com; tel: 908-507-5500 iRoof™ Structural Analysis Software www.princeton-engineering.com/framinganalysis.html STRUCTURAL ANALYSIS for the Vision Solar ROOFTOP PV SOLAR INSTALLATION Project: David Farrell; Location: 113 Williams Street, Northampton, MA 01060 Vision Solar 511 Route 168 - Blackwood, NJ 08021 VS Project 7060 Report Date: 09/02/2021 TectoniCorp, P.C. Princeton Engineering Solar, Structural, Electrical and Site Engineering 35091 Paxson Road - Round Hill, Virginia 20141 tel: 540.313.5317 - fax: 877.455.5641 - www.Princeton-Engineering.com Richard J. Pantel, P.E. MA License No. 49678 Structural PE Project Number: 9675.7060, Rev. 0 Prepared by: Prepared for: 1 of 8 Loading Summary Exposure and Occupancy Categories B II Wind Loading: v 117 mph Northampton, MA - 780 CMR: MA Wind / Snow / Seismic Amendment Values - IBC 2015 qz 20.85 psf pg 40 psf Ground Snow Load pg (ASCE 7-10 Table 7.1, Page 34-35) Total Snow Load ps 25.20 psf 2.3 psf 2.1 psf 4.4 psf mm ft in 1,755 5.76 69.09 1,038 3.41 40.87 1.8 19.61 kg lb 19.50 42.99 Roof Panel (Cladding) Loading Summary Module Loading Summary Upward Upward Upward Downward 1 2 3 All lb -66 -84 -84 275 Lag Bolt Data Size 5/16x3.00 Pre-drill 0.16" dia Material Stainless Rack Support Lag Bolt Pull-out Calculations in US Douglas-fir Roof Framing 1 2 3 lb 66 84 84 2 2 2 2.00 2.00 2.00 lb/in 283 283 283 in 0.23 0.30 0.30 in 1.50 1.50 1.50 in 3.00 3.00 3.00 Safety Factor Bolt Pullout Per Module Connection Area (m^2, ft^2) Net total load / support point Roof Zone Pull-out for 5/16 dia bolts Min threaded inches embedment required Min threaded Inches embedment provided Min Lag Bolt length to use Number of Pullout Loads / Support Exposure Category (ASCE 7-10 Table 26.7.3, Page 246) Building Use Occupancy / Risk Category (ASCE 7-10 Table 1.5-1, Page 2) Snow Loading Velocity qz, calculated at height z [ASD] Item Module Data Notes 1 Shingles, Asphalt, 3-Tab (Typical) 0.5" Plywood decking Effective snow load on roof and modules ROOF DEAD LOAD SUMMARY (exclusive of wood framing) Longi Solar: LR4-60HPH-355M Dimensions Length Roof Zone Roof surface Deck Material Total Loading Weight Module Support Point Loads Width Loading Summary R iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.2 of 8 Conclusions 7-10 NE 03.jpg Framing Summary Bracket to Roof Framing Lag Bolts US Douglas-fir rafters have a bolt pullout strength of 283 lb / inch of thread using the 5/16" dia. fasteners. In order to maintain at least a 2X Safety Factor for pullout, 1.5 inches of THREAD embedment are required. Use a 3.00" x 5/16" stainless lag bolt, or larger, in order to achieve the above specified embedment into each joist at each rail support point. Predrill with a 0.16" dia pilot hole. References and Codes: Google Location Map Princeton Engineering was asked to review the roof of David Farrell, located at 113 Williams Street, Northampton, MA by Vision Solar, to determine its suitability to support a PV solar system installation. The referenced building's roof structure has been field measured by Vision Solar on 08/26/2021. The framing calculations we prepared reflect the results of those field measurements combined with the PV solar module locations shown on the construction PV solar roof layout design prepared by Vision Solar. Loads are calculated to combine the existing building and environmental loads with the proposed new PV array loads. Vision Solar has selected the Ecolibrium Solar ECO-X racking system. The racking support brackets shall be placed as shown on the plans prepared by Vision Solar, dated 09/02/2021, and shall be fastened to the roof deck using lag bolt sizes as indicated in this report. Rack support spacing shall be no more than shown on each calcluation. Note that support points for alternating rows shall share the same rafter. Intermediate rows shall move the support points to laterally the next rafter. NOTE: Rafters upon which stanchions will placed, require collar ties or knee walls. Collar tie / knee wall locations either exist or will be added at the heights indicated herein. All new collar tiles shall be 2x6 material and shall be fastened at each end with (8) 10D common nails. If knee walls are to be used, stud framing to match rafter locations. Install top and bottom plate. All material to be 2x4 fastened w/10D common nails. Notes: (1) Bolt threads must be embedded in the side grain of a rafter or other structural member integral with the building structure. (2) Lag bolts must be located in the middle third of the structural member. (3) Install lag bolts with head and washer flush to surface (no gap). Do not over-torque. Based upon the attached calculations, the roof, as described above, IS capable of supporting the additional loading for the proposed Vision Solar PV system along with the existing building and environmental loads. Loading Summary R iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.3 of 8 1) ASCE 7-10 Minimum Design Loads for Buildings and Other Structures 2) IBC 2015 including MA wind / snow amendment 3) 780 CMR: MA IBC Wind Amendment for wind and snow loads 4) American Wood Council, NDS 2005,Table 11.2A, 11.3.2A. 5) American Wood Council, Wood Structural Design, 1992, Figure 6. Loading Summary R iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.4 of 8 Roof Structural Calculations for PV Solar Installation Array AR-1 Location: MP1 Member:Rafter - Total Length 14.17 ft, Unsupported 6.83 ft deg.33.01 ft.15.00 ft.39.92 ft.24.000 Roof Wind Zone Width use, a =3.00 ft Wind Velocity Pressure, q z evaluated at the height z q z=20.85 psf Vasd q z=12.61 psf Basic wind pressure V=117 mph Framing Data 2 # Rafters / Rack Support Width 1 4.00 Rack Support Spacing (ft) in 24.00 ft 14.17 2 Max # of mod's / Rafter Member * Mem properties based upon field measurements (1)1.5x5.5 Rafter 1.15 psi 800 psi 1,130 48.00 Collar tie OC spacing, in. Uphill Dist Between Mounting Holes (ft) Module Data Longi Solar: LR4-60HPH-355M kg lb psf load 19.50 42.99 2.19 0.91 2.0 0.10 20.41 45.0 2.29 psf psf 0.86 psf 4.40 psf 2.29 Portrait Rack Support Spacing and Loading ft 4.0 ft 5.8 sf 11.5 in 1.0 0.08 ft ft 14.17 ft 6.83 ft 6.83 180 Use max delta 1/x for deflection * Collar tie height @ 4.00' AFF max height. Adjust to match lowest adjoining roof's collar tie as neededFree span Deflection Ratio Rafter segment to calc Maximum member free span Rafter above Collar tie Framing Member PV Module + Stanchion 4 Stanchions Total Module and Support load Module Roof Data Angle of plane of roof from horizontal, in degrees Length of Building, in feet (meters). Width of Building, in feet (meters). Height of Building, in feet (meters). Rafter / Truss OC Wood source, moisture content Wood type Ө L W h Coast 0.12% Max Shear parallel to grain Module Orientation Uphill gap between modules US Douglas-fir Along rafter slope Area / support point Weight Member Total Length Member Properties Name Max Shear perp. to grain Dead Load Summary Existing Roof Repetitive Member Factor (Cr) # Framing Members / Support Member Total Length Across rafters Array AR-1 iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.5 of 8 0.83 ft 1.00 ft . ASCE 7-10 Chapter 2 Combinations of Loads, Table 2.4, Page 8 (in psf) 1 2 3 1, 2 & 3 Module Upward Module Upward Module Upward Downward 2.29 2.29 2.29 2.29 25.20 25.20 25.20 25.20 -11.88 -14.40 -14.40 10.98 2.4 Combining Nominal Loads Using Allowable Stress Design (in psf) 2.4.1 Basic Combinations. Loads listed herein shall be considered to act in the following combinations; whichever produces the most unfavorable effect in the building, foundation, or structural member being considered. Effects of one or more loads not acting shall be considered. Upward Upward Upward Downward Use this loading combination for DOWNWARD: 27.49 27.49 27.49 27.49 317 317 317 317 275 275 275 275 Use this loading combination for UPWARD: -5.75 -7.26 -7.26 1.38 -66 -84 -84 16 DOWNWARD Presume loading directly over member. Combined Dead and Wind Pressure Downward Loading Rafter above Collar tie PV Module Row Point load loc's from Left support Point Loading Comment Module Rotated 90 Degrees ft from left lb 1 0.17 0 Support outside of max stressed section 1 5.93 0 Support outside of max stressed section 2 6.01 0 Support outside of max stressed section 2 11.77 275 W = wind load Cr Factored Support point loading Support point loading 3. D + S 7. 0.6D + 0.6W Combination Formulae Eave Overhang Length past Rafter Plate S = snow load D = dead load of PV Module + Stanchion Uphill Distance from Eave to Lowest Support Support point loading 2.2 SYMBOLS AND NOTATION Zones Array AR-1 iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.6 of 8 Analysis for PV impacted areas 5. Simple Beam - Exposed Roof Snow Load - Above and Below PV Units Total Allowed Check Delta @ mid span in 0.13 0.46 OK M at mid span lb-ft 706 5,210 OK Sum Downward Loading Conditions: PV; Beam DL; Exposed Roof Environmental Load Units Total Allowed Check in 0.20 0.46 OK %45%100%OK lb-ft 1,067 5,210 OK psi 1,693 8,267 OK * Loading includes member self weight & roofing materials. w loading = wind & snow on exposed areas Truss Graphing Tools Framing section with max stress: Rafter above Collar tie Percent Max Delta Moment fs Delta Parameter Parameter Floor CT-Ex P2 -2 0 2 4 6 8 10 -1 1 3 5 7 9 11 Array AR-1 iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.7 of 8 Snow Loading Analysis where: Fully Exposed Exposure category Ce =0.9 Exposure Factor, Ce (ASCE 7-10 Table 7-2, Page 30) Ct =1.0 Thermal Factor, Ct (ASCE 7-10 Table 7-3, Page 30) Is =1.0 Snow Importance Factor, Is (ASCE 7-10 Table 1.5-2, Page 5) pg =40 Ground Snow Load pg (ASCE 7-10 Table 7.1, Page 34-35) pf =0.7CeCtIspg Flat Roof Snow Load, pf (ASCE 7-10 Table 7-2, Page 30) pf =25.2 but where Pf is not less than either of the following: Minimum Snow Load pm (ASCE 7-10 Table 7.3.4, Page 29) pm =40 When Pg <=20 psf, then use Pf = Pg x Is OR pm =20 When Pg > 20 psf, then use Pf = 20 psf x Is <== Use this value pf =25.2 Resultant Snow pressure in psf to be used with Roof slope factor below ps =Cspf Sloped Roof Snow Load ps (ASCE 7-10 Table 7.4, Page 31) Roof Type Warm Roofs Roof slope factor Cs for Warm Roofs, where Ct = 1.0 Roof surface condition = Slippery Roof Cs =1.00 Roof Slope Factor, Cs (ASCE 7-10 Table 7-2a, Page 36) Total Snow Load ps =25.20 psf Roof snow load Snow Loading iRoof TM Copyright © 2020 Richard Pantel. All Rights Reserved.8 of 8