30C-058 JB-0101859-00 Reva-Golden_ENP_MA_TBD s Version #53.6 - TBD
RE: CERTIFICATION LETTER
Project/Job # 0101859
Project Address: Golden Residence
376 Florence Rd
Florence, MA 01062
AHJ NorthamptonSC Office Springfield
Design Criteria:
- Applicable Codes = MA Res. Code, 8th Edition, ASCE 7-05, and 2005 NDS
- Risk Category = II
- Wind Speed = 90 mph, Exposure Category C
- Ground Snow Load = 40 psf
- MP1: Roof DL = 7.5 psf, Roof LL/SL = 28 psf (Non-PV Areas), Roof LL/SL = 28 psf (PV Areas)
- MP4: Roof DL = 12.5 psf, Roof LL/SL = 28 psf (Non-PV Areas), Roof LL/SL = 28 psf (PV Areas)
Note: Per IBC 1613.1; Seismic check is not required because Ss = 0.22424 < 0.4g and Seismic Design Category (SDC) = B < D
To Whom It May Concern,
March 7, 2016
A jobsite survey of the existing framing system of the address indicated above was performed by a site survey team from SolarCity.
Structural evaluation was based on site observations and the design criteria listed above.
Additionally, I certify that the PV module assembly including all standoffs supporting it have been reviewed to be in accordance with the
manufacturer’s specifications and to meet and/or exceed all requirements set forth by the ASCE 7 standards for loading.
Based on this evaluationI certify that the existing structure directly supporting the PV system is adequate to withstand all loading indicated
in the design criteria above based on the requirements of the applicable existing building and/or new building provisions
adopted/referenced above.
The PV assembly hardware specifications are contained in the plans submitted for approval. Additionally a summary of the structural
review is provided in the results summary tables on the following page.
Version #53.6 - TBD
X-X Spacing X-X Cantilever Y-Y Spacing Y-Y Cantilever Configuration Uplift DCR
MP1 64''24''39''NA Staggered 39.9%
MP4 64''24''39''NA Staggered 39.8%
X-X Spacing X-X Cantilever Y-Y Spacing Y-Y Cantilever Configuration Uplift DCR
MP1 48''18''65''NA Staggered 49.7%
MP4 48''18''65''NA Staggered 49.6%
Type Spacing Pitch
MP1 Stick Frame @ 16 in. O.C.26°
MP4 Stick Frame @ 16 in. O.C.24°
Member Evaluation Results
Member Analysis OK
Member Analysis OK
HARDWARE DESIGN AND STRUCTURAL ANALYSIS RESULTS SUMMARY TABLES
Mounting Plane Framing
Hardware - Portrait Modules' Standoff Specifications
Hardware - Landscape Modules' Standoff Specifications
Qualification ResultsStructure
Landscape
Hardware
Portrait
Hardware
Refer to the submitted drawings for details of information collected during a site survey. All member analysis and/or evaluation is based on framing information
gathered on site. The existing gravity and lateral load carrying members were evaluated in accordance with the IBC and the IEBC.
Overhang 0.66 ft Actual W 1.50''
Span 1 12.16 ft Actual D 5.50''
Number of Spans (w/o Overhang)1 Span 2 Nominal Yes
Roofing Material Comp Roof Span 3 A 8.25 in.^2
Re-Roof No Span 4 Sx 7.56 in.^3
Plywood Sheathing Yes Span 5 Ix 20.80 in.^4
Board Sheathing None Total Rake Span 14.26 ft TL Defl'n Limit 120
Vaulted Ceiling No PV 1 Start 1.17 ft Wood Species SPF
Ceiling Finish 1/2" Gypsum Board PV 1 End 12.00 ft Wood Grade #2
Rafter Slope 26°PV 2 Start Fb 875 psi
Rafter Spacing 16'' O.C.PV 2 End Fv 135 psi
Top Lat Bracing Full PV 3 Start E 1400000 psi
Bot Lat Bracing At Supports PV 3 End Emin 510000 psi
Roof Pitch 6/12 Initial Pitch Adjust Non-PV Areas PV Areas
Roof Dead Load DL 7.5 psf x 1.11 8.3 psf 8.3 psf
PV Dead Load PV-DL 3.0 psf x 1.11 3.3 psf
Roof Live Load RLL 20.0 psf x 0.90 18.0 psf
Live/Snow Load LL/SL1,2 40.0 psf x 0.7 ǀ x 0.7 28.0 psf 28.0 psf
Total Load (Governing LC)TL 36.3 psf 39.7 psf
Governing Load Comb CD CL (+)CL (-)CF Cr
D + S 1.15 1.00 0.54 1.3 1.15
Governing Analysis Max Demand @ Location Capacity DCR Result
Bending (+) Stress 1539 psi 6.8 ft 1504 psi 1.02 Pass
STRUCTURE ANALYSIS - LOADING SUMMARY AND MEMBER CHECK - MP1
Member Properties Summary
MP1 Horizontal Member Spans Rafter Properties
Notes: 1. ps = Cs*pf; Cs -roof, Cs -pv per ASCE 7 [Figure 7-2] 2. pf = 0.7 (Ce) (Ct) (Is) pg ; Ce=0.9, Ct=1.1, Is=1.0
Member Design Summary (per NDS)
Roof System Properties
Member Loading Summary
Member Analysis Results Summary
Roofing Material
PV System Type
Spanning Vents
Standoff (Attachment Hardware)
Roof Slope
Rafter Spacing
Framing Type / Direction
Purlin Spacing X-X Purlins Only
Tile Reveal Tile Roofs Only
Tile Attachment System Tile Roofs Only
Standing Seam/Trap Spacing SM Seam Only
Wind Design Code
Wind Design Method
Basic Wind Speed V Fig. 6-1
Exposure Category Section 6.5.6.3
Roof Style Fig. 6-11B/C/D-14A/B
Mean Roof Height h Section 6.2
Wind Pressure Exposure Kz Table 6-3
Topographic Factor Kzt Section 6.5.7
Wind Directionality Factor Kd Table 6-4
Importance Factor I Table 6-1
Ext. Pressure Coefficient (Up)GCp (Up)Fig. 6-11B/C/D-14A/B
Ext. Pressure Coefficient (Down)GCp (Down)Fig. 6-11B/C/D-14A/B
Design Wind Pressure p Equation 6-22
Wind Pressure Up p(up)Wind Pressure Down p(down)
Y-Direction
Max Allowable Standoff Spacing Landscape 39''Max Allowable Cantilever Landscape NA
Standoff Configuration Landscape
Max Standoff Tributary Area Trib
PV Assembly Dead Load W-PV
Net Wind Uplift at Standoff T-actual
Uplift Capacity of Standoff T-allow
Standoff Demand/Capacity DCR
Y-Direction
Max Allowable Standoff Spacing Portrait 65''
Max Allowable Cantilever Portrait NA
Standoff Configuration Portrait
Max Standoff Tributary Area Trib
PV Assembly Dead Load W-PV
Net Wind Uplift at Standoff T-actual
Uplift Capacity of Standoff T-allow
Standoff Demand/Capacity DCR
No
Comp Mount Type C
26°
CALCULATION OF DESIGN WIND LOADS - MP1
Mounting Plane Information
Comp Roof
SolarCity SleekMount™
16'' O.C.
Y-Y Rafters
NANA
NA
NA
C
Gable Roof
15 ft
Wind Design Criteria ASCE 7-05
Partially/Fully Enclosed Method
90 mph
qh qh = 0.00256 (Kz) (Kzt) (Kd) (V^2) (I)Equation 6-1515.0 psf
Wind Pressure
-0.88
Wind Pressure Calculation Coefficients
0.85
1.00
0.85
1.0
Velocity Pressure
0.45
p = qh (GCp)
-13.1 psf
24''
-199 lbs
10.0 psf
ALLOWABLE STANDOFF SPACINGS
X-Direction
64''
500 lbs
39.9%
X-Direction
48''18''Staggered
Staggered
17 sf3.0 psf
22 sf3.0 psf
-249 lbs500 lbs
49.7%
Overhang 0.66 ft Actual W 1.50''
Span 1 8.61 ft Actual D 5.50''
Number of Spans (w/o Overhang)2 Span 2 8.67 ft Nominal Yes
Roofing Material Comp Roof Span 3 A 8.25 in.^2
Re-Roof No Span 4 Sx 7.56 in.^3
Plywood Sheathing Yes Span 5 Ix 20.80 in.^4
Board Sheathing Solid-Sheathing Total Rake Span 19.64 ft TL Defl'n Limit 120
Vaulted Ceiling No PV 1 Start 1.75 ft Wood Species SPF
Ceiling Finish 1/2" Gypsum Board PV 1 End 16.50 ft Wood Grade #2
Rafter Slope 24°PV 2 Start Fb 875 psi
Rafter Spacing 16'' O.C.PV 2 End Fv 135 psi
Top Lat Bracing Full PV 3 Start E 1400000 psi
Bot Lat Bracing At Supports PV 3 End Emin 510000 psi
Roof Pitch 6/12 Initial Pitch Adjust Non-PV Areas PV Areas
Roof Dead Load DL 12.5 psf x 1.09 13.7 psf 13.7 psf
PV Dead Load PV-DL 3.0 psf x 1.09 3.3 psf
Roof Live Load RLL 20.0 psf x 0.93 18.5 psf
Live/Snow Load LL/SL1,2 40.0 psf x 0.7 ǀ x 0.7 28.0 psf 28.0 psf
Total Load (Governing LC)TL 41.7 psf 45.0 psf
Governing Load Comb CD CL (+)CL (-)CF Cr
D + S 1.15 1.00 0.73 1.3 1.15
Governing Analysis Max Demand @ Location Capacity DCR Result
Bending (-) Stress -879 psi 9.3 ft -1093 psi 0.80 Pass
STRUCTURE ANALYSIS - LOADING SUMMARY AND MEMBER CHECK - MP4
Member Properties Summary
MP4 Horizontal Member Spans Rafter Properties
Notes: 1. ps = Cs*pf; Cs -roof, Cs -pv per ASCE 7 [Figure 7-2] 2. pf = 0.7 (Ce) (Ct) (Is) pg ; Ce=0.9, Ct=1.1, Is=1.0
Member Design Summary (per NDS)
Roof System Properties
Member Loading Summary
Member Analysis Results Summary
Roofing Material
PV System Type
Spanning Vents
Standoff (Attachment Hardware)
Roof Slope
Rafter Spacing
Framing Type / Direction
Purlin Spacing X-X Purlins Only
Tile Reveal Tile Roofs Only
Tile Attachment System Tile Roofs Only
Standing Seam/Trap Spacing SM Seam Only
Wind Design Code
Wind Design Method
Basic Wind Speed V Fig. 6-1
Exposure Category Section 6.5.6.3
Roof Style Fig. 6-11B/C/D-14A/B
Mean Roof Height h Section 6.2
Wind Pressure Exposure Kz Table 6-3
Topographic Factor Kzt Section 6.5.7
Wind Directionality Factor Kd Table 6-4
Importance Factor I Table 6-1
Ext. Pressure Coefficient (Up)GCp (Up)Fig. 6-11B/C/D-14A/B
Ext. Pressure Coefficient (Down)GCp (Down)Fig. 6-11B/C/D-14A/B
Design Wind Pressure p Equation 6-22
Wind Pressure Up p(up)Wind Pressure Down p(down)
Y-Direction
Max Allowable Standoff Spacing Landscape 39''Max Allowable Cantilever Landscape NA
Standoff Configuration Landscape
Max Standoff Tributary Area Trib
PV Assembly Dead Load W-PV
Net Wind Uplift at Standoff T-actual
Uplift Capacity of Standoff T-allow
Standoff Demand/Capacity DCR
Y-Direction
Max Allowable Standoff Spacing Portrait 65''
Max Allowable Cantilever Portrait NA
Standoff Configuration Portrait
Max Standoff Tributary Area Trib
PV Assembly Dead Load W-PV
Net Wind Uplift at Standoff T-actual
Uplift Capacity of Standoff T-allow
Standoff Demand/Capacity DCR
No
Comp Mount Type C
24°
CALCULATION OF DESIGN WIND LOADS - MP4
Mounting Plane Information
Comp Roof
SolarCity SleekMount™
16'' O.C.
Y-Y Rafters
NANA
NA
NA
C
Gable Roof
15 ft
Wind Design Criteria ASCE 7-05
Partially/Fully Enclosed Method
90 mph
qh qh = 0.00256 (Kz) (Kzt) (Kd) (V^2) (I)Equation 6-1515.0 psf
Wind Pressure
-0.88
Wind Pressure Calculation Coefficients
0.85
1.00
0.85
1.0
Velocity Pressure
0.45
p = qh (GCp)
-13.1 psf
24''
-199 lbs
10.0 psf
ALLOWABLE STANDOFF SPACINGS
X-Direction
64''
500 lbs
39.8%
X-Direction
48''18''Staggered
Staggered
17 sf3.0 psf
22 sf3.0 psf
-248 lbs500 lbs
49.6%