HomeMy WebLinkAboutLA208913-APPROVED - Thomas Fisher - Roof EvaluationSTRUCTURAL CERTIFICATION REPORT
Roof-mounted Solar Panels
December 16, 2022
To: Powerfully Green Re: Thomas Fisher
2010 E Hennepin Ave.17452 Iceland Trail
Minneapolis, MN 55413 Lakeville, MN 55044
Powerfully Green proposes to install new roof-mounted solar panels at this residence and asked Right Angle Engineering
to review the existing structure for suitability. This letter summarizes the methods that were used to survey, evaluate, and
certify the existing roof framing and the attachment of the new solar panels to it. Pictures and calculations are available
on request.
STRUCTURAL DESIGN
Building Code:International Residential Code 2018
Design Standards:ASCE 7-16
Snow:Ground: pg= 50.0 psf | Flat Roof: pf= 34.65 psf | Sloped Roof: ps= 30.03 psf
Wind:Ultimate Wind Speed = 115.0 mph | Exposure = C
Seismic:Risk Category = 2 | Seismic Design Category = A | Site Class = D
STRUCTURE
Field Technicians from Powerfully Green visited the site and observed the existing structure :
Array Name Panel Quantity Roof Framing Material Pitch
Array 1 3 2x4 Truss DF#2 | 24" o.c.Asphalt Shingles 18
Array 2 15 2x4 Truss DF#2 | 24" o.c.Asphalt Shingles 18
Array 3 10 2x4 Truss DF#2 | 24" o.c.Asphalt Shingles 18
ANCHORAGE
The solar panel anchorage shall be installed according to the manufacturer's most current installation manual.
Anchorage shall be staggered to distribute the load evenly to adjacent roof members. The solar panels should be
mounted flush to the roof surface.
Array Name Connection Type Fastener Max Anchorage Spacing
Array 1
Sunmodo NanoMount with (4)
#14 roof screws into 3/4 inch
OSB
(4) Self-tapping screws,
#14x3.00 (0.5" embedment)
into roof substructure
34"
Array 2
Sunmodo NanoMount with (4)
#14 roof screws into 3/4 inch
OSB
(4) Self-tapping screws,
#14x3.00 (0.5" embedment)
into roof substructure
34"
Array 3
Sunmodo NanoMount with (4)
#14 roof screws into 3/4 inch
OSB
(4) Self-tapping screws,
#14x3.00 (0.5" embedment)
into roof substructure
34"
Installation Instructions
Solar panels and the equipment shall be installed per the manufacturer's installation specifications. Improper installation
will void this certification. Deviations from the approved structural plans (including equipment substitutions) are not
allowed without written approval from Right Angle Engineering. Prior to installation, the installer should:
•Confirm that the existing structure matches the information provided in the structural survey, the approved
installation plans and this certification.
•Identify discrepancies between this certification and the approved installation plans. If found, then this
certification shall govern.
•Identify structural elements that are dangerous (cracked, broken, excessive sag, signs of overstress, rot,decay,
fire, water). If found, installation shall cease until those elements are adequately abated and made to comply with
the referenced building code.
•Provide fire setbacks and access pathways as required by local ordinances
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 1 of 2
STRUCTURAL CERTIFICATION
I certify the addition of solar panels on the roof of this structure does not cause the structure to become unsafe or make
it generally less compliant with the life-safety requirements of the referenced building code. Based on the evaluation
methods described below, for the loads that exist at this site, the existing framing should safely support the new solar
panels if they are installed and attached correctly. Electrical design is not included in this certification.
Array Name Certification Method Retrofits
Array 1 Stress analysis International Residential code None required
Array 2 Stress analysis International Residential code None required
Array 3 Stress analysis International Residential code None required
Regards,
12/16/2022
Robert D. Smythe, P.E.
Right Angle Engineering
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 2 of 2
Concept Approval ONLYSubject to Field Inspection
Inspector Date
2020
MN Bldg
Code
12/16/2022dpfannenstein
Please provide a copy of
the City Approved plans on
site at final inspection.