BLD2022-1195_Structural_Calculations_9.8.2022_2.02.51_PM_3097711structural
ENGINEERS
January 12, 2022
Unirac
1411 Broadway Blvd. NE
Albuquerque, NM 87102
Attn.: Unirac - Engineering Department
Re: Engineering Certification for the Unirac U-Builder 2.0 SOLARMOUNT Flush Rail
PZSE, Inc. - Structural Engineers has reviewed the Unirac SOLARMOUNT rails, proprietary mounting system constructed
from modular parts which is intended for rooftop installation of solar photovoltaic (PV) panels; and has reviewed the U-
builder Online tool. This U-Builder software includes analysis for the SOLARMOUNT LIGHT rail, SOLARMOUNT
STANDARD rail, and SOLARMOUNT HEAVY DUTY rail with Standard and Pro Series hardware. All information, data and
analysis contained within are based on, and comply with the following codes and typical specifications:
1. Minimum Design Loads for Buildings and other Structures, ASCE/SEI 7-05, ASCE/SEI 7-10, ASCE/SEI 7-16
2. 2006-2018 International Building Code, by International Code Council, Inc. w/ Provisions from SEAOC PV-2 2017
3. 2006-2018 International Residential Code, by International Code Council, Inc. 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. 2015 Aluminum Design Manual, by The Aluminum Association, 2015
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 Engineering report.
Cantilever: Maximum cantilever length is L/3, where "L" is the span noted in the U-Builder 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 roof and the PV
panel is mounted on the long side.
Portrait - PV Panel short dimension is parallel to ridge/eave line of roof and the PV panel
is mounted on the short side.
1478 Stone Point Drive, Suite 190, Roseville, CA 95661
916.961.3960 916.961.3965 www.pzse.com 1 of 2
structurai
ENGINEERS
Components and Cladding Roof Zones:
The Components and Cladding Roof Zones shall be determined based on ASCE 7-05, ASCE 7-10 & 7-16 Component and
Cladding design.
Notes: 1) U-builder Online tool analysis is only for Unirac SM SOLARMOUNT Rail Flush systems only 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 Ye = 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 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 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 Software is applicable to the project, and
Understand and determine the appropriate values for all input parameters of the U-Builder software.
This letter certifies that the Unirac SM SOLARMOUNT Rails Flush, when installed according to the U-Builder engineering
report and the manufacture specifications, is 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.
DIGITALLY SIGNED
If you have any questions on the above, do not hesitate to call.
Prepared by:
PZSE, Inc. — Structural Engineers
Roseville, CA
EXPIRES 08/02/2023
1478 Stone Point Drive, Suite 190, Roseville, CA 95661
916.961.3960 916.961.3965 www.pzse.com 2of2
2"X2"
AHJ APPROVAL
STAMP
CAPSTONE
SOLAR
DESCRIPTION I DATE IDWG NO.
ORIGINAL 1 2022-9-2 1 1
Solar Specialist
DAVID NICOL
System Engineer
TIM WACHTMAN
System Designer
CASEY MILLER
I Customer Info I
VIC SUNG LAM & HERMAN HOY LAM
17806 73RD PLACE WEST
EDMONDS, WA 98026
PARCEL# 00473700000800
Project Details
10.95 KW
ROOFTOP PV
SYSTEM
TILT
1:12 PITCH
AZIMUTH
253°/ 73°
DC SYSTEM RATING
8.76 KW
AC SYSTEM RATING
9.6KW
ESTIMATED ANNUAL PRODUCTION
10,880 KWh/Yr
EQUIPMENT:
RACKING SYSTEM,
ENGINEERING STAMP
Sheet
S-5
ENGINEERING REPORT
Plan review
* Distributed Dead Load 2.54 psf
* Average Roof Point Dead Load 13.28 Ibs
TOTAL NUMBER OF MODULES
30
TOTAL KW
10.95 KW
TOTAL MODULE AREA
-.596 ft2
Loads Used for Design
BUILDING CODE
ASCE 7-10
BASIC WIND SPEED
110.00 mph
GROUND SNOW LOAD
25.00 psf
SEISMIC (SS)
1.310
ELEVATION
310.00 ft
WIND EXPOSURE
B
TOPOGRAPHICAL FACTOR KZT
1.00
VELOCITY PRESSURE, QZ
15.92 psf
Loads Determined by Zip
98026
CITY, STATE
Edmonds, WA
BASIC WIND SPEED
110.00 mph
GROUND SNOW LOAD
15.00 psf
* Calculated based on suggested quantity given on part list
Inspection
PRODUCT
MODULE MANUFACTURER
MODEL
MODULE WATTS
MODULE LENGTH
MODULE WIDTH
MODULE THICKNESS
MODULE WEIGHT
EXPANSIONJOINTS
RAILS DIRECTION
BUILDING HEIGHT
SHORTEST BUILDING LENGTH
ROOF TYPE
RAFTER SPACING
• TOTAL WEIGHT
MID CLAMP
END CLAMP
SOLARMOUNT FLUSH
United Renewable Energy
30 - F6M365E7G-BB
365 watts
69.37"
41.26"
1.38"
43.21 Ibs
Every 40'
CROSS -SLOPE
30.00 ft
20.00 ft
Other
24.00"
1513.80 Ibs
Universal AF Clamp
Universal AF Clamp
Roof Area 1: Array 1
Landscape Modules - Rails Running Across Slope (for rails with attachments > 3)
SOLARMOUNT LIGHT RAIL SPANS
ZONE 1
ZONE 2
ZONE 3
MAXIMUM POINT LOADS [LBS]
ZONE 1
ZONE 2
ZONE 3
[IN]
Up
-67.4
-127.9
-204.2
DESIGN SPAN
48
48
48
Down
178.1
178.1
178.1
Max Cantilever
16
16
16
Downslope
22.0
22.0
22.0
Max Span
76
76
72
Lateral
15.1
15.1
15.1
ZONES ZONE
ZONE
ZONE
Tributary Area [ft2]
6.9
6.9
6.9
NO OF RAILS
2
2
2
ROOF PITCH:
50
DESIGN PRESSURES [PSF]
ZONE 1
ZONE 2
ZONE 3
Up
-9.8
-18.6
-29.7
Down
25.9
25.9
25.9
Downslope
3.2
3.2
3.2
Lateral
2.2
2.2
2.2
Landscape Modules - Rails Running
Across Slope (for rails with attachments <= 3)
SOLARMOUNT LIGHT RAIL SPANS
ZONE 1
ZONE 2
ZONE 3
MAXIMUM POINT LOADS [LBS]
ZONE 1
ZONE 2
ZONE 3
[IN]
Up
-67.4
-127.9
-204.2
DESIGN SPAN
48
48
48
Down
178.1
178.1
178.1
Max Cantilever
16
16
16
Downslope
22.0
22.0
22.0
Max Span
76
76
72
Lateral
15.1
15.1
15.1
ZONES
ZONE 1
ZONE 2
ZONE 3
Tributary Area [ft2] 6.9 6.9 6.9
NO OF RAILS
2
2
2
ROOF PITCH: 50
DESIGN PRESSURES [PSF]
ZONE 1
ZONE 2
ZONE 3
Up
-9.8
-18.6
-29.7
Down
25.9
25.9
25.9
Downslope
3.2
3.2
3.2
Lateral
2.2
2.2
2.2
2"XZ"
AHJ APPROVAL
STAMP
L
CAPSTONE
SOLAR
DESCRIPTION DATE DWG NO
ORIGINAL 2022-9-2 ]
Solar Specialist
DAVID NICOL
System Engineer
TIM WACHTMAN
System Designer
CASEY MILLER
Customer Info
VIC SUNG LAM & HERMAN HOY LAM
17806 73RD PLACE WEST
EDMONDS, WA 98026
PARCEL# 00473700000800
Project Details
10.95 KW
ROOFTOP PV
SYSTEM
TILT
1:1 Z PITCH
AZIMUTH
Z53°/ 73°
DC SYSTEM RATING
8.76 KW
AC SYSTEM RATING
9.6KW
ESTIMATED ANNUAL PRODUCTION
10,880 KWh/Yr
Drawing
EQUIPMENT:
RACKING SYSTEM, SITE
SPECIFIC ENGINEERING
Sheet
S-6