B-2016-1434 FRAMING CERT LETTER®iaf Its/
February 9, 2016
RE:
Project/Job # 9506471
Project Address:
AHJ
SC Office
Design Criteria:
CERTIFICATION LETTER
Thompson Residence
22248 Hammond Way
Cupertino, CA 95014
Cupertino
.Foster City
Applicable Codes = 2013 CBC, ASCE 7-10, and 2012 NDS
Risk Category = II
Wind Speed = 110 mph, Exposure Category C
Ground/Roof Snow Load = 0 psf
MPS: Roof DL = 15 psf, Roof LL = 18 psf
MP2: Roof DL = 15 psf, Roof LL = 18 psf
Per Section 1613.1, W-(PV)/ W-(exist roof) = 4.4%, Increase Seismic Shear Load < 10%, -> [OK]
To Whom It May Concern,
Version #53.6 - TBD
Digitally signed
by Henry Zhu
Date: 2016,02.09
22:53:16-08'00'
Ajobsite 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.
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.
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.
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.
RECEIVED
ED
3055 Clearview Way San Mateo, CA 94402 T (650) 638-1028 (888) SOL-CITY r (650) 638-1029 colareity.com
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SEISMIC CONSIDERATIONS
Seismic Design Criteria(per USGS
SeismicDesignCode
ASCE 7-10
Latitude
37.3311
Longitude
-122.0823
SRA at Short Period
Ss
2.548
USGS
SRA at is Period
Sl
1.298
USGS
Soil Site Class
D
IBC 1613.5.2
Seismic Design Category
SDC
E
USGS
Seismic Check Required (Ss>_
-
IBC 1613.1
0.4 & SDC ? D
.Yes
ALTERATION LATERAL DESIGN 10% EXCEPTION CHECK
Weight of Proposed PV System
Area
Dead ad Lo
Weight
PV System Weight -
Total Weight of PV System
W(PV)
551 sf
3 sf
1,6 :2 lbs
1,652 lbs
Weight of Roof on Existing Building
Sum Area of MPs with PV
1343 sf
'Portion of Roof Weight
-
Area
Dead Load
- Weight.
Roof
Ceiling
Interior Walls (Top Half)
Exterior Walls CTop Half
1,343 sf
15.0 psf
20,150 lbs
-
1343:sf
6.5 psf
8,732 lbs
586 sf
5.0 psf
2,932 lbs
586 sf
85 psf
4,985 lbs
Net Weight of Roof Under PV
Wtext:tl
36,799 lbs
Check% Increase of Roof Weight /'Seismic Shear Load
% Increase of DCR of Lateral
W Wexmt)
(PV)� (
_
4.5% u
IBC Sect. 3404.4
Force Resisting stem
Increase Seismic Shear Load < 10 /o > OK
, ( ]
Note: Seismic base shear is directly proportional to roof weight.
CALCULATION OF DESIGN WIND LOADS - MP1
Mounting Plane Information
Roofing Material
Flat Tile Roof
PV System Type
_
SoldrClty'.SleekMount'"'
Spanning Vents
No
Standoff Attachment Hardware
Mighty Hook HOG FT
-
Roof Slope
270
Rafter Spacing
-. 24"OTC,
Framing Type / Direction
Y-Y Rafters
Purlin Spacing
X-X Purlins Only
- NA
Tile Reveal
Tile Roofs Only
13"
Tile Attachment System
Tile Roofs Only
SM Span
-,
,Standing Seam/TrapSeam/Trap Spacing
SM Seam Only
NA
Wind Design Criteria
Wind Design Code
ASCE 7-10
Wind Design Method
Partially/Fully Enclosed Method
Basic Wind Speed
V
110 mph
Fig. 26.5-1A
Exposure Category
C
Section 26.7
Roof Style
Gable Roof
Fig. 30.42A/B/C-5A/B
Mean Roof Height
h.
15 ft.
- Section 26.2.
Wind Pressure Calculation Coefficients
Wind Pressure Exposure
Kz
0.85
Table 30.3-1
Topographic Factor -
Kn
1.00
Section.26.8
Wind Directionality Factor
Ka
0.85
Section 26.6-1
importance Factor -
I
NA
Velocity Pressure
qh
qh = 0.00256 (Kz) (Kzt) (Kd) (VA2)
Equation 30.3-1
22.4 psf
Wind Pressure.
Ext. Pressure Coefficient U
GC u
-0.88
Fig. 30.4-2A/B/C-5A/B
Ext. Pressure Coefficient Down
GC pow
0.45
'Fig. 30.4-2A/13/C-5A/13
Design Wind Pressure
p
P = gh (GC)
Equation 30.4-1
Wind Pressure Up
p „
-19.6 psf
Wind Pressure Down
down
16.0 psf
ALLOWABLE STANDOFF SPACINGS
X-Direction -
Y-Direction
Max Allowable Standoff Spacing
Landscape
72"
52"
Max Allowable Cantilever
Landscape
24"
24"
Standoff Configuration
Landscape
Not -Staggered
Max Standoff Tributary Area. _
Trib
26 sf
PV Assembly Dead toad
W-PV
3.0 psf
Net Wind Uplift at Standoff
T-actual
-263 Ibs
Uplift Capacity of Standoff
T-allow
500 Ibs
Standoff Demand/Capacity
DCR
52.7%
X-Direction.
Y-Direction
Max Allowable Standoff Spacing
Portrait
48"
52"
Max Allowable Cantilever
Portrait
20"
24"
Standoff Configuration
Portrait
Not -Staggered
Max Standoff Tributary. Area
Trib
17 sf
PV Assembly Dead Load. _
W-PV
3.0 psf
Net Wind Uplift at Standoff
T-actual
-176 Ibs.
Uplift Capacity of Standoff
T-allow
500 Ibs
Standoff Demand Ca aci
OCR
35.16/o
CALCULATION OF DESIGN WIND LOADS - MP2
Mounting Plane Information
Roofing Material
Flat Tile Roof
PV System Type
SolarCity SleekMountT`"
Spanning Vents
No
Standoff Attachment Hardware
Mighty Hook HDG FT
Roof Slope
270
Rafter Spacing
24" O.C.
Framing Type Direction
Y-Y Rafters
Purlin.Spacing
X-X Purlins Only
NA
Tile Reveal
Tile Roofs Only
13"
Tile Attachment System
Tile Roofs Only
SM Span
,Standing Seam/TrapSeam/Trap Spacing
SM Seam Only
NA
Wind Design Criteria
Wind Design Code
ASCE 7-10
Wind Design Method
Partially/Fully Enclosed Method
Basic Wind Speed
V
110 mph
Fig. 26.5-1A
Exposure Category
C
Section 26.7
Roof Style
Gable Roof
FIg. 30.4-2A/B/C-SA/B
Mean Roof Height
h
15 ft
Section 26.2
Wind Pressure Calculation Coefficients
Wind Pressure Exposure
K�
0.85
Table 30.3-1
Topographic Factor
Krt
1.00
Section 26.8
Wind Directionality Factor
Kd
_
0.85
Section 26.6-1
Im ortance Factor
I
- NA
Velocity Pressure
qh
qh = 0.00256 (Kz) (Kzt) (Kd) (VA2)
Equation 30.3-1
22.4 psf
Wind Pressure
Ext. Pressure Coefficient U
GC
-0.88
Fig. 30.4-2A/B/C-5A/B
Ext. Pressure Coefficient ( Down
GC Down
0.45
Fig. 30.42A/B/C-5A/B
Design Wind Pressure
p
p = qh (GC)
Equation 30.4-1
Wind Pressure U
p "
19.6 psf
Wind Pressure Down.
dow"
16.0 psf
ALLOWABLE STANDOFF SPACINGS
X-Direction
Y-Direction
Max Allowable Standoff Spacing
Landscape
48"
52"
Max Allowable Cantilever
Landscape
24" -
24"
Standoff Configuration
Landscape
Not -Staggered
Max Standoff Tributary Area
Trib
17 sf
PV Assembly Dead Load
W-PV
3.0 psf
Net Wind. Uplift at Standoff
T-actual
-176 Ibs -
Uplift Capacity of Standoff
T-allow
500 Ibs
Standoff Demand Ca aci
DCP
35.1%
X-Direction,
Y-:Direction
Max Allowable Standoff Spacing
Portrait
48"
52"
Max Allowable Cantilever
Portrait
20"
24"
Standoff Configuration
Portrait
Not -Staggered
Max Standoff Tributary Area
Trib
17 sf
PV Assembly Dead Load
W-PV
3.0 psf
Net Wind Uplift at Standoff
T-actual
-176 Ibs
Uplift. Capacity of Standoff
T-allow
500 Ibs
Standoff Demand/Capacity
DCR
35.1%