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Home My WebLink About1957 Mathhew Pritzker Letter 8.5.2021 strucutral letterBOWERS ENGINEERING SERVICES WWW.BOWERSENG.COM 121 S. MAIN ST PHONE (260) 333-0900 AUBURN, INDIANA 46706 FAX (260) 333-0901 $XJXVW, 2021 BES Project Number: 1957 Matthew Pritzker Power Home Solar, LLC 919 N Main St. Mooresville, NC 28115 Project Location: Matthew Pritzker: 3231 Eden Way Cir., Carmel, IN 46033 Solar Array Installation To Whom It May Concern: Per your request, BES has reviewed the existing structure at the above referenced location. The purpose of this 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 attached panel layout plan. Based upon our review, we certify that existing roof structure will adequately support with the following: Racking and attachment 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. Solar module mounting hardware design is by the manufacturer. 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 BES 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 to not overload any existing structural member. The design of the solar panel racking (mounts, rails, etc.) is the responsibility of the manufacturer. Waterproofing around the roof penetrations is the responsibility of others. BES assumes no responsibility for improper installation of the solar array. Existing structure meets or exceeds standard building practices with current building code with assumed single layer asphalt shingles. Sincerely, Jermey Bowers M.E., P.E. Principal Engineer 08/05/2021 10/04/21 Project: 1957 Rev: - Page 1 of 5 121 S. Main ST Bowers Engineering Services Auburn, IN (260) 333-0900 ________________________________ Structural Analysis Location 3231 Eden Way Cir. Roof Mount Solar 8/5/2021 Carmel, IN 46033 08/05/2021 10/04/21 BES Date: 8/5/2021 Connections 121 South Main ST Auburn, IN Cust. Name: Bowers Engineering Services Subject: Roof Mount Job Number: 1957 Originator 0 Checker: STRUCTURAL SUMMARY CODE SPEC WIND IBC 2012 Speed:115 MPH ASCE 7-10 Exp.:C Risk Cat: II Wind Load - uplift Max lb Zone 1 -21.88 psf -147 lb Zone 2 -40.98 psf -275.36 lb Zone 3 -62.85 psf -422.36 lb Max trib 11.20 ft2 Max loading at connection Negitive -422.36 lb/fastener Connection (Pull Out) Lag screw 5/16 in Cd 1.60 Table 2.3.2 embedment 2.5 in Nominal CapacityPrying 205.00 lbs G=0.42 Max capacity (lbs) 533.00 > 422.36 OK Note: * Lag screws to be diameter 5/16x2.5inches long. * All fasteners need to be placed at roof rafters. PAGE2 OF 5 10/04/21 BES WIND LOADING 121 South Main ST Per ASCE 7-10 Auburn, IN Cust Name: Bowers Engineering Services Subject: Roof Mount Job Number: 1957 Originator: 0 Checker: Input Data: Wind Speed, V = 115 mph (Wind Map, Figure 26.5-1A-C) Bldg. Classification = II (Table 1-1 Occupancy Category) Exposure Category = C (Sect. 26.7) Ridge Height, hr = 17.38 ft. (hr >= he) Eave Height, he = 10.00 ft. (he <= hr) Building Width = 29.50 ft. (Normal to Building Ridge) Building Length = 75.00 ft. (Parallel to Building Ridge) Roof Type = Gable (Gable or Monoslope) Topo. Factor, Kzt = 1.00 (Sect. 26.8 & Figure 26.8-1) Direct. Factor, Kd = 0.85 (Table 26.6) Enclosed? (Y/N) Y (Sect. 28.6-1 & Figure 26.11-1) Hurricane Region? N Component Name = Decking (Purlin, Joist, Decking, or Fastener) Effective Area, Ae = 11.1 ft.^2 (Area Tributary to C&C) Overhangs? (Y/N) N (if used, overhangs on all sides) Resulting Parameters and Coefficients: Roof Angle, T = 26.57 deg. Mean Roof Ht., h = 13.69 ft. (h = (hr+he)/2, for roof angle >10 deg.) Roof External Pressure Coefficients, GCp: GCp Zone 1-3 Pos. = 0.49 (Fig. 30.4-2A, 30.4-2B, and 30.4-2C) GCp Zone 1 Neg. = -0.90 (Fig. 30.4-2A, 30.4-2B, and 30.4-2C) GCp Zone 2 Neg. = -1.68 (Fig. 30.4-2A, 30.4-2B, and 30.4-2C) GCp Zone 3 Neg. = -2.57 (Fig. 30.4-2A, 30.4-2B, and 30.4-2C) Positive & Negative Internal Pressure Coefficients, GCpi (Figure 26.11-1): +GCpi Coef. = 0.00 (positive internal pressure) -GCpi Coef. = 0.00 (negative internal pressure) If z <= 15 then: Kz = 2.01*(15/zg)^(2/D) , If z > 15 then: Kz = 2.01*(z/zg)^(2/D) (Table 30.3-1) D = 9.50 (Table 26.9-1) zg = 900 (Table 26.9-1) Kh = 0.85 (Kh = Kz evaluated at z = h) Velocity Pressure: qz = 0.00256*Kz*Kzt*Kd*V^2 (Sect. 30.3.2, Eq. 30.3-1) qh = 24.43 psf qh = 0.00256*Kh*Kzt*Kd*V^2 (qz evaluated at z = h) Design Net External Wind Pressures (Sect. 30.4 & 30.6): For h <= 60 ft.: p = qh*((GCp) - (+/-GCpi)) (psf) For h > 60 ft.: p = q*(GCp) - qi*(+/-GCpi) (psf) where: q = qh for roof qi = qh for roof (conservatively assumed per Sect. 30.6) PAGE 3 of 5 To L B hr heh Plan Elevation L 10/04/21 Wind Load Tabulation for Roof Components & Cladding Component z Kh qh p = Net Design Pressures (psf) (ft.) (psf) Zone 1,2,3 (+) Zone 1 (-) Zone 2 (-) Zone 3 (-) Decking 0 0.85 24.43 11.99 -21.88 -40.98 -62.85 15.00 0.85 24.43 11.99 -21.88 -40.98 -62.85 For z = hr: 17.38 0.85 24.43 11.99 -21.88 -40.98 -62.85 For z = he: 10.00 0.85 24.43 11.99 -21.88 -40.98 -62.85 For z = h: 13.69 0.85 24.43 11.99 -21.88 -40.98 -62.85 Notes: 1. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces. 2. Width of Zone 2 (edge), 'a' = 3.00 ft. 3. Width of Zone 3 (corner), 'a' = 3.00 ft. 4. For monoslope roofs with T <= 3 degrees, use Fig. 30.4-2A for 'GCp' values with 'qh'. 5. For buildings with h > 60' and T > 10 degrees, use Fig. 30.6-1 for 'GCpi' values with 'qh'. 6. For all buildings with overhangs, use Fig. 30.4-2B for 'GCp' values per Sect. 30.10. 7. If a parapet >= 3' in height is provided around perimeter of roof with T <= 10 degrees, Zone 3 shall be treated as Zone 2. 8. Per Code Section 30.2.2, the minimum wind load for C&C shall not be less than 16 psf. 9. References : a. ASCE 7-02, "Minimum Design Loads for Buildings and Other Structures". b. "Guide to the Use of the Wind Load Provisions of ASCE 7-02" by: Kishor C. Mehta and James M. Delahay (2004). PAGE 4of 5 10/04/21 Roof Components and Cladding: TT <= 7 deg. 7 deg. < T <= 27 deg. 27 deg. < T <= 45 deg. Roof Zones for Buildings with h <= 60 ft. (for Gable Roofs <= 45o and Monoslope Roofs <= 3o) Roof Zones for Buildings with h > 60 ft. (for Gable Roofs <= 10o and Monoslope Roofs <= 3o) PAGE 5 of 5 10/04/21 Frame Design General Info Cust. Name: Bowers Engineering Services Subject: Roof Mount Job Number: 1957 Originator: Checker: Date: 44413 Address 3231 Eden Way Cir. Rev: - City, State: Carmel, IN 46033 Roof Rafter Roof Loads Rafter Size= 2x6 SYP Dead Load= 6 psf #1 Live Load= 20 psf Trib. Area= 1.33 ft Snow Load= 20 psf Rafter length= 14 ft Load Combination D+0.75L+0.75S 36.0 psf EI= 3.3E+07 ib-in w= 47.88 plf Sx = 7.5625 CM= 1.0 M= 1173.06 lb-ft Cr= 1.2 CD= 1.15 CF= 1.3 CL= 1.0 Fb= 1500 psi fb= 1861.38 psi F'b= 2578.88 psi OK ǻ/ 0.69 in ǻ6 0.69 in ǻ'/ 0.90 in l/120 ǻallow in= 0.90 < 1.40 OK l/180 ǻallow in= 0.69 < 0.93 OK 2x6 @ 1.33 o/c OK *Assume rafters are fully braced* ͷݓ݈ସ ͵ͺͶܧܫ ݂ܾ=ܯכ12 ܵݔ Fᇱܾ =ܨܾכܥ݀כܥݎכܥ݂כܥ݉כܥ݈ 10/04/21