HomeMy WebLinkAboutLA208343-APPROVED - Engineering Certification of SM-MNEngineering Alliance, Inc
https://www.eng-alliance.com
4603 April Meadow Way, Sugar Land, TX 77479. Ph: 832 865 4757
11-November-2022
Unirac
1411 Broadway Blvd. NE
Albuquerque, NM 87101
Tel: 505 242 6411
Attn.: Engineering Department
Subject: Engineering Certification for the Unirac SOLARMOUNT Flush Rail System to Support Photovoltaic Panels.
The Unirac SOLARMOUNT Flush-to-Roof is an extruded aluminum rail system that is engineered to hold most framed solar
modules to a roof structure and installed parallel to the roof.
We have reviewed the SOLARMOUNT system, a proprietary mounting system constructed from modular parts which are
intended for rooftop installation of solar photovoltaic (PV) panels; and have reviewed the U-Builder 2.0 Online tool. This U-
Builder 2.0 software includes analysis for the SOLARMOUNT rails (SM LIGHT rail, SM STANDARD rail, and SM HEAVY DUTY rail)
with Standard and Pro Series hardware. All information, data, and analysis are in compliance with the following codes, city
ordinances, and typical specifications:
Codes: 1. ASCE/SEI 7-16 Minimum Design Loads for Buildings and other Structures
2. 2020 Minnesota Building Code, w/ Provisions from SEAOC PV-2 2017
3. 2020 Minnesota Residential Code, w/ Provisions from SEAOC PV-2 2017
4. AC428, Acceptance Criteria for Modular Framing Systems Used to Support Photovoltaic (PV) Panels,
November 1, 2012 by ICC-ES
5. Aluminum Design Manual, 2015 & 2020 Edition
Following are typical specifications to meet the above code requirements:
Design Criteria: Ground Snow Load = 0 - 100 (psf)
Basic Wind Speed = 85 - 190 (mph)
Roof Mean Height = 0 - 60 (ft)
Roof Pitch = 0 - 45 (degrees)
Exposure Category = B, C & D
Attachment Spacing: Per U-Builder 2.0 Engineering report.
Cantilever: The maximum cantilever length is L/3, where “L” is the span noted in the U-Builder 2.0 online
Tool.
Clearance: 2” to 10” clear from top of roof to top of PV panel
Tolerance(s): 1.0” tolerance for any specified dimension in this report is allowed for installation
Installation Orientation: See SOLARMOUNT Rail Flush Installation Guide.
Landscape - PV Panel long dimension is parallel to ridge/eave line of the roof and the PV panel is
mounted on the long side.
Portrait - PV Panel short dimension is parallel to ridge/eave line of the roof and the PV panel is
mounted on the short side.
Engineering Alliance, Inc
https://www.eng-alliance.com
4603 April Meadow Way, Sugar Land, TX 77479. Ph: 832 865 4757
Components and Cladding Roof Zones:
The Components and Cladding Roof Zones shall be determined based on ASCE 7-05, 7-10 & 7-16 Component and Cladding
design.
Notes: 1. U-Builder 2.0 Online tool analysis is only for Unirac SM SOLARMOUNT Rail Flush systems
and do not include roof capacity check.
2. Risk Category II per ASCE 7-16.
3. Topographic factor, kzt is 1.0.
4. Array Edge Factor ƳE = 1.5
5. Average parapet height is 0.0 ft.
6. Wind speeds are LRFD values.
7. Attachment spacing(s) apply to a seismic design category E or less.
Design Responsibility:
The U-Builder 2.0 design software is intended to be used under the responsible charge of a registered design professional where
required by the authority having jurisdiction. In all cases, this U-Builder 2.0 software should be used under the direction of a
design professional with sufficient structural engineering knowledge and experience to be able to:
• Evaluate whether the U-Builder 2.0 Software is applicable to the project, and
• Understand and determine the appropriate values for all input parameters of the U-Builder 2.0 software.
This letter certifies that the Unirac SM SOLARMOUNT Rails Flush, when installed according to the U-Builder 2.0 engineering
report and the manufacture specifications are in compliance with the above codes and loading criteria.
This certification excludes evaluation of the following components:
1) The structure to support the loads imposed on the building by the array; including, but not limited to: strength and
deflection of structural framing members, fastening and/or strength of roofing materials, and/or the effects of snow
accumulation on the structure.
2) The attachment of the SM SOLARMOUNT Rails to the existing structure.
3) The capacity of the solar module frame to resist the loads.
This requires additional knowledge of the building and is outside the scope of the certification of this racking system.
Please feel free to call for any questions or clarifications.
Prepared By:
Engineering Alliance, Inc
Sugar Land, TX
Professional Engineer
I hereby certify that this plan, specification, or report was
prepared by me or under my direct supervision and that I am
a duly Licensed Professional Engineer under the laws of the
state of Minnesota.
Signature:
Typed or Printed Name: Saddam Ahmad
Date: License Number: 5538111-NOV-2022
Concept Approval ONLYSubject to Field Inspection
Inspector Date
2020
MN Bldg
Code
11/16/2022dpfannenstein
Provide copy of city approved plans
on the job site for the inspector