Structural Calculation - Signed (22) (1)RE:CERTIFICATION LETTER
Project Address: BARRY GRUBER
128 BROOKSIDE CIR
NORTHAMPTON, MA 01062
Design Criteria:
- Applicable Codes = 2015 IBC/IEBC W/(780 CMR) 9th Edition, 2015 IRC W/(780 CMR) 9th Edition, ASCE 7-10 and 2015 NDS
- Risk Category = II
- Wind Speed = 117 mph, Exposure Category B, Partially/Fully Enclosed Method
- Ground Snow Load = 40 psf
- ROOF 1 & 2: 2 x 4 @ 24" OC, Roof DL = 9 psf, Roof LL/SL = 35 psf (Non-PV), Roof LL/SL = 27.4 psf (PV)
To Whom It May Concern,
July 18, 2023
This document is the property of Barun Corp and cannot be reproduced without prior consent.It is site specific and shall not be transferred to any other property,
property owner,person(s),or entity.This document may include an expression of professional opinion by the engineer of record,which is based on his or her best
knowledge,information provided by others,and belief.Other professionals may have different opinions.Barun Corp reserves the right to amend and/or supplement
this document in the event additional information be uncovered or made available.
A structural evaluation of loading was conducted for the above address based on the design criteria listed above.
Existing roof structural framing has been reviewed for additional loading due to installation of Solar PV System on the roof. The structural
review applies to the sections of roof that is directly supporting the Solar PV System.
Based on this evaluation, I certify that the alteration to the existing structure by installation of the Solar PV System meets the prescriptive
compliance requirements of the applicable existing building and/or new building provisions adopted/referenced above.
Additionally, the Solar PV System assembly (including attachment hardware) has been reviewed to be in accordance with the manufacturer’s
specifications and to meet and/or exceed the requirements set forth by the referenced codes.
Sincerely,
Barun Corp | Design and Engineering | 610.202.4506 | chrisk@baruncorp.com | www.baruncorp.com 1/4
ROOF PITCH
23°
Limits of Scope of Work and Liability:
The existing structure has been reviewed based on the assumption that it has been originally designed and constructed per appropriate
codes.The structural analysis of the subject property is based on the provided site survey data.The calculations produced for this
structure's assessment are only for the roof framing supporting the proposed PV installation referenced in the stamped planset and were
made according to generally recognized structural analysis standards and procedures.All PV modules,racking and attachment
components shall be designed and installed per manufacturer’s approved guidelines and specifications.These plans are not stamped for
water leakage or existing damage to the structural component that was not accessed during the site survey.Prior to commencement of
work,the PV system installer should verify that the existing roof and connections are in suitable condition and inspect framing noted on
the certification letter and inform the Engineer of Record of any discrepancies prior to installation.The installer should also check for any
damages such as water damage,cracked framing,etc.and inform the Engineer of Record of existing deficiencies which are unknown
and/or were not observable during the time of survey and have not been included in this scope of work.Any change in the scope of the
work shall not be accepted unless such change, addition, or deletion is approved in advance and in writing by the Engineer of Record.
BARUN CORP RESULTS SUMMARY
BARRY GRUBER, 128 BROOKSIDE CIR, NORTHAMPTON, MA 01062
MOUNTING PLANE STRUCTURAL EVALUATION
MOUNTING PLANE
ROOF 1 & 2
GOVERNING ANALYSIS
IEBC IMPACT CHECK
RESULT
OK
MOUNTING PLANE
STANDOFF HARDWARE EVALUATION FOR WIND UPLIFT
WIND UPLIFT DCR
Barun Corp | Design and Engineering | 610.202.4506 | chrisk@baruncorp.com | www.baruncorp.com 2/4
PV Panels Weight =2.50 psf
Hardware Assembly Weight =0.50 psf
PV-DL =3.00 psf
Existing Roofing Material Weight 2 Layer(s)=5.00 psf
Underlayment Weight =0.50 psf
Plywood/OSB Sheathing Weight =1.50 psf
Framing Weight =0.73 psf
No Vaulted Ceiling =0.00 psf
Miscellaneous =1.50 psf
Total Roof Dead Load R-DL =9.20 psf
Roof Live Load Lo =20.00 psf
Member Tributary Area At <200 ft2
ROOF 1 & 2 Pitch 23° or 5/12
Tributary Area Reduction Factor R1 =1.00
Roof Slope Reduction Factor R2 =0.95
Reduced Roof Live Load, Lr = Lo (R1) (R2)Lr =19.00 psf
Ground Snow Load pg =40.00 psf
Effective Roof Slope 23°
Snow Importance Factor Is =1.00
Snow Exposure Factor Ce =1.00
Snow Thermal Factor Ct =1.10
Minimum Flat Roof Snow Load pf-min =35.00 psf
Flat Roof Snow Load pf =35.00 psf
Roof Slope Factor Cs-roof =1.00
Sloped Roof Snow Load on Roof ps-roof =35.00 psf
Roof Slope Factor Cs-PV =0.78
Sloped Roof Snow Load on PV Panels ps-PV =27.40 psf
BARUN CORP ROOF 1 & 2
LOAD CALCULATION
BARRY GRUBER, 128 BROOKSIDE CIR, NORTHAMPTON, MA 01062
PV PANELS DEAD LOAD (PV-DL)
ROOF DEAD LOAD (R-DL)
Total PV Panels
2 x 4 @ 24 in. O.C.
REDUCED ROOF LIVE LOAD (Lr)
SNOW LOAD
SLOPED ROOF SNOW LOAD ON ROOF (Non-Slippery Surfaces)
Composite Shingle Roof
SLOPED ROOF SNOW LOAD ON PV PANELS (Unobstructed Slippery Surfaces)
Barun Corp | Design and Engineering | 610.202.4506 | chrisk@baruncorp.com | www.baruncorp.com 3/4
psf
psf
psf
psf
psf
psf
-10.41%OK
WITH PV PANELS
13.56
34.43
Roof Live Load (Lr) =
ROOF 1 & 2
EXISTING
9.20
WITH PV PANELS
BARRY GRUBER, 128 BROOKSIDE CIR, NORTHAMPTON, MA 01062
EXISTING
12.20
0.00
BARUN CORP IEBC IMPACT CHECK
Roof Snow Load (SL) =27.40
Roof Dead Load (DL) =
19.00
35.00
The requirements of section 807.4 of 2015 IEBC are met and the structure is permitted to remain unaltered.
Load Increase (%) =
(DL + Lr)/Cd =
(DL + SL)/Cd =
Maximum Gravity Load =
22.56
38.43
38.43 34.43
Barun Corp | Design and Engineering | 610.202.4506 | chrisk@baruncorp.com | www.baruncorp.com 4/4