22B-026 (5) as �s
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ECTOR RECEIVED
E rT G I fT E E R S
OCT 2 4 2018
VSE Project Number:U1982-0892-181
DEPT DE DIatDING INSPECTIDNs
October 23,2018 NOBTNRMPTDu.
IMoroso
Trinity Solar
ATTENTION:Phil Smith
4 Open Square Way,Suite 410
Holyoke,MA 01040
REFERENCE: Lindsay Slabich Residence: 21 Corticelli Street,Northampton,MA 01062
Solar Arrav Installation
To Whom It May Concern:
Per your request, we have reviewed the existing structure at the above referenced site. The purpose of our 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 panel layout plan. Based upon out review,we conclude that the existing structure will require retrofit in order to support
the proposed solar panel installation.The existing rafters of roof 3 must be retrofit by installing a new 2x6 the full length of
the existing rafter.install the new 2x6 rafter with 16d sinkers at 6"O.C.staggered.Roof I is permitted to remain unaltered.
Design Parameters
Code:Massachusetts State Residential Code(780 CMA Chapter 51,9th Edition(2015 IRC))
Risk Category:D
Design wind speed: 117 mph (3-sec gust)per ASCE 7-10
Wind exposure category:C
Ground snow load: 40 psf
Existin¢Roof Structure
Roof structure:true 2.4 rafters @ 24"O.C.
Roofing material:asphalt shingles
Roofslope:40°
Connection to Roof
Mounting connection:(1)5/16'lag screw w/min.2.6'embedment into framing at max.72"O.C.along mils
Conclusions
Based upon our review,we conclude that the existing structure will require retrofit in order to support the proposed solar
panel installation. The glass surface of the solar panels allows for a lower slope factor per ASCE 7, resulting in reduced
design snow load on the panels. The attached calculations verify the adequacy of the roof m support the solar array after the
aforementioned retrofit is complete.
651 W.Galena Park Blvd.,Ste. 101/Draper,UT 84020/T(801)990-1775/F(801)990-1776/www.vectorse.com
JOB NO.: U1982-0892-181
��/ECTOR SUBJECT: WIND PRESSURE
n e j n E= rz R s
PROJECT: Lindsay Slabich Residence
Fc—o,p,n,nt,and Cladding Wind Cali
Label: ISolar Panel Array Note: Calculations per ASCE 7-10
SITE-SPECIFIC WIND PARAMETERS:
Basic Wind Speed [mph]: 117 Notes:
Exposure Category: C
Risk Category: 11
ADDITIONAL INPUT& CALCULATIONS:
Height of Roof, h [ft]: 20 (Approximate)
Comp/Cladding Location: Gable Roofs 27*<O5 45*
Enclosure Classification: Enclosed Buildings
Zone 1 GCP: 1,0 Figure 30.4-2C (enter largest abs. value)
Zone 2 GCP: 1.2 (enter largest abs. value)
Zone 3 GCP: 1.2 (enter largest abs. value)
a 9.5 Table 26.9-1
zg [ft]: 900 Table 26.9-1
Kh: 0.90 Table 30.3-1
K,: 1 Equation 26.8-1
Kd: 0.85 Table 26.6-1
Velocity Pressure, ch [psf]: 26.9 Equation 30.3-1
GCP,: 0 Table 26.11-1 (largest abs. value)
OUTPUT: 1 p—qhlt,C, Equation 30.9-1 W
Zone 1 Pressure, p [psf]: 26.9 psf(1.0 W, Interior Zones*)
Zone 2 Pressure, p [psf]: 32.2 psf(1.0 W, End Zones*)
Zone 3 Pressure, p [psf]: 32.2 psf(1.0 W, Corner Zones'within a)
(a= 3 ft)
VECTOR GRAM
JOB NO.: 0892-181
SUBJECT: GRAVITY LOADS
E 71 O 1 m E E R 8
PROJECT: Lindsay Slabich Residence
CALCULATE ESTIMATED GRAVITY LOADS
Increase due to Original
ROOF DEAD LOAD D pitch loading
Roof Pitch/12 10.1
Asphalt Shingles 2.6 1.31 2.0 psf
1/2" Plywood 1.3 1.31 1.0 psf
Framing 3.0 psf
Insulation 0.0 psf
1/2"Gypsum CIg. 0.0 psf
M, E & Misc 0.0 psf
OL 7 psf
PV Array DL 4 psf
ROOF LIVE LOAD (Lr)
Existing Design Roof Live Load [psf] 20 ASCE 7-10,Table 4-1
Roof Live Load With PV Array[psfJ
w/Solar Panel
SNOW LOAD (S): Existing Array
Roof Slope[x:12]: 10.1 10.1
Roof Slope [°]: 40 40
Snow Ground Load, p9 [psf]: 40 40 ASCE 7-10,Section 7.2
Terrain Category: C C ASCE 7-10,Table 7-2
Exposure of Roof: Fully Exposed Fully Exposed ASCE 7-10,Table 7-2
Exposure Factor, Ca: 0.9 0.9 ASCE 7-10,Table 7-2
Thermal Factor, CI: 1.1 1.1 ASCE 7-10,Table 7-3
Risk Category: II 11 ASCE 7-10,Table 1.5-1
Importance Factor, Is: ;Fe57-2;b
1.0 ASCE 7-10,Table 1.5-2
Flat Roof Snow Load, pt[psf]: 35 ASCE 7-10, Equation 7.3-1
Minimum Roof Snow Load, p. [psf]: 0 ASCE 7-10,Section 7.3.4
Unobstructed Slippery Surface? Yes ASCE 7-10,Section 7.4
Slope Factor Figure: Fi ure 7-2b ASCE 7-10,Section 7.4
Roof Slope Factor, C,: 0.50 ASCE 7-10, Figure 7-2
Sloped Roof Snow Load, ps [psfl: 32 18 ASCE 7-10, Equation 7.4-1
Design Snow Load, S [psf]: 32 18
YECTOR
JOB NO.: U1982-0892-181
SUBJECT: SOLAR LAYOUT
f
PROJECT: Lindsay Slabich Residence
A
2
12
4
A
A
S
10
11
9