HomeMy WebLinkAboutLA224045 - APPROVED-TOM KING Permit PlansConcept Approval ONLYSubject to Field Inspection
Inspector Date
2015
MN Bldg
Code
05/23/2024jnuetzman
STRUCTURAL CERTIFICATION REPORT
Roof-mounted Solar Panels
May 20, 2024
To: All Energy Solar Re: Tom King - 83060
1264 Energy Lane 4774 165th St W
St. Paul, MN 55108 Lakeville, MN 55044
AHJ: Lakeville (City), MN
All Energy Solar 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.
STRUCTURAL DESIGN
Building Code:Minnesota Residential Code 2020
Design Standards:ASCE 7-16
Snow:Ground: pg= 60.0 psf | Flat Roof: pf= 41.58 psf | Sloped Roof: ps= 24.95 psf
Wind:Ultimate Wind Speed = 109.0 mph | Exposure = C
Seismic:Risk Category = 2 | Seismic Design Category = A | Site Class = D
STRUCTURE
Field Technicians from All Energy Solar visited the site and observed the existing structure :
Array Name Panel Quantity Roof Framing Material Pitch
Array 1 7 Pre-Manufactured Truss | 24"
o.c.Asphalt Shingles 45°
Array 2 23 Pre-Manufactured Truss | 24"
o.c.Asphalt Shingles 34°
Array 3 2 Pre-Manufactured Truss | 24"
o.c.Asphalt Shingles 34°
Array 4 4 Pre-Manufactured Truss | 24"
o.c.Asphalt Shingles 34°
ANCHORAGE
The solar panel anchorage shall be installed according to the manufacturer's most current installation manual. The
attachment configuration should match the certified building plans. The solar panels should be mounted parallel (max 5
inches) to the roof surface.
Array Name Connection Type Fastener Max Anchorage Spacing
Array 1 Anchor Foot
5/16” lag screw (2.5"
embedment) into roof
substructure
48"
Array 2 Anchor Foot
5/16” lag screw (2.5"
embedment) into roof
substructure
24"
Array 3 Anchor Foot
5/16” lag screw (2.5"
embedment) into roof
substructure
24"
Array 4 Anchor Foot
5/16” lag screw (2.5"
embedment) into roof
substructure
24"
Installation Instructions
Solar panels and the equipment shall be installed per the manufacturer's installation specifications. Improper installation
will void this certification. If deviations from the approved structural plans occur, Right Angle Engineering must be
notified. Prior to installation, the installer should:
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 1 of 7
•Confirm that the existing structure matches the information provided in the site 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.
•Verify that both the existing structure and the solar addition has been permitted through the AHJ.
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 will 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 Prescriptive method Minnesota Conservation Code for Existing
Buildings code 806.2 None required
Array 2 Prescriptive method Minnesota Conservation Code for Existing
Buildings code 806.2 None required
Array 3 Prescriptive method Minnesota Conservation Code for Existing
Buildings code 806.2 None required
Array 4 Prescriptive method Minnesota Conservation Code for Existing
Buildings code 806.2 None required
Regards,
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 7
Job Details
Roof Snow Load - ASCE 7-16
Ground Snow Load (pg)
Section 7.2 60.0 psf
Exposure Factor (Ce)
Table 7.3-1 0.9
Thermal Factor (Ct)
Table 7.3-2 1.1
Importance Factor (Is)
Table 1.5-2 1
Flat Roof Snow Load (pƒ)
Equation 7.3-1 41.58 psf
Non-Slippery Surface Slope Factor
(Cs) Figure 7.4-1 1
Slippery Surface Slope Factor (Cs)
Figure 7.4-1 0.6
Roof Snow Load
Equation 7.4-1 41.58 psf
Reduced Snow Load (Slippery
Surface)
Equation 7.4-1
24.95 psf
Design Criteria
Wind Speed (Vult)
Local Design Criteria 109.0mph
Exposure Category C
Risk Category 2
Mean Roof Height 20 ft
Roof Type Gable Roof
Building Type Enclosed
Roof Live Load
Existing Roof Live Load
ASCE 7-16 Table 4.3-1 20 psf
1Roof Dead Load
Asphalt Shingles 2.0 psf No Drywall 0.0 psf
5/8" Plywood Sheathing 2.0 psf Solar Panel Array 2.74 psf
Roof Framing 4 psf Dead Load Without Panels 9.2 psf
Insulation 1.2 psf
1Roof Dead Load is taken from the worst case scenario dead load from all arrays of the job in order to provide a more
conservative evaluation.
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 3 of 7
Array 1
Array Details
Roof Framing Pre-Manufactured
Truss
Spacing 24.0"
Beam Span 17.0'
Roof Pitch 45°
Panel Quantity 7
Panel Array Area 151.45 ft²
Panel Orientation Portrait
Lag Screw Embedment 2.5"
Roof Attachment Type Anchor Foot 5/16” lag
screw
Shear Capacity
NDS 190.0 lbs
Pullout Capacity
NDS 665.0 lbs
Velocity Pressure
Equation 26.10-1 (Kz=0.9, Kht=1,
Kd=0.85, Ke=0.97)
22.54 psf
GCP Zones 1/2e/
2r 2n/3r 3e
GCpFigure 30.3-(2A-5B)-1.8 -2.0 -3.2
Design Pressure Up [psf]
Equation 29.4-7 ga=0.49 gE=1.0,-20.0 -22.2 -35.6
Factored Design Pressure
Up [psf]
ASD LC (.6D + .6W)
-10.9 -12.2 -20.2
Exposed Design Pressure
Up [psf]
ga=0.49 gE=1.5,
-30.0 -33.4 -53.4
Design Pressure Down
[psf]8.9 8.9 8.9
Tributary Area [ft2]13.4 13.4 13.4
Maximum Connection
Spacing [in]51 51 51
Maximum Rail Span [in]48 48 48
Maximum Rail Cantilever
[in]16 16 16
Design Connection
Spacing [in]48 48 48
Deign Connection Spacing
(exposed) [in]48 48 48
Prescriptive Method: Minnesota Conservation Code for Existing Buildings Code 806.2
Total load on member without solar 1878.86 lbs
Total load on member with solar 1357.44 lbs
Percentage of total design load on member with solar 0.72%
The 2020 Minnesota Conservation Code for Existing Buildings section 806.2 indicates that alterations to an existing
building that results in less than a 5.0% increase in the total stress may be performed without a structural evaluation of
the existing building. As demonstrated in the above calculations, the additional weight of the solar panels will be less
than 5.0% increase in the gravity loading and therefore stress on the existing roof framing. Load case before and load
case after solar panels have been added have both been considered according to Minnesota State Building Code
1607.13.5.1.
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 4 of 7
Array 2
Array Details
Roof Framing Pre-Manufactured
Truss
Spacing 24.0"
Beam Span 25.0'
Roof Pitch 34°
Panel Quantity 23
Panel Array Area 497.61 ft²
Panel Orientation Portrait
Lag Screw Embedment 2.5"
Roof Attachment Type Anchor Foot 5/16” lag
screw
Shear Capacity
NDS 190.0 lbs
Pullout Capacity
NDS 665.0 lbs
Velocity Pressure
Equation 26.10-1 (Kz=0.9, Kht=1,
Kd=0.85, Ke=0.97)
22.54 psf
GCP Zones 1/2e/
2r 2n/3r 3e
GCpFigure 30.3-(2A-5B)-1.8 -2.0 -3.2
Design Pressure Up [psf]
Equation 29.4-7 ga=0.49 gE=1.0,-20.0 -22.2 -35.6
Factored Design Pressure
Up [psf]
ASD LC (.6D + .6W)
-10.7 -12.0 -20.0
Exposed Design Pressure
Up [psf]
ga=0.49 gE=1.5,
-30.0 -33.4 -53.4
Design Pressure Down
[psf]8.9 8.9 8.9
Tributary Area [ft2]12.3 12.3 12.3
Maximum Connection
Spacing [in]47 47 47
Maximum Rail Span [in]48 48 48
Maximum Rail Cantilever
[in]8 8 8
Design Connection
Spacing [in]24 24 24
Deign Connection Spacing
(exposed) [in]24 24 24
Prescriptive Method: Minnesota Conservation Code for Existing Buildings Code 806.2
Total load on member without solar 2691.34 lbs
Total load on member with solar 1822.31 lbs
Percentage of total design load on member with solar 0.68%
The 2020 Minnesota Conservation Code for Existing Buildings section 806.2 indicates that alterations to an existing
building that results in less than a 5.0% increase in the total stress may be performed without a structural evaluation of
the existing building. As demonstrated in the above calculations, the additional weight of the solar panels will be less
than 5.0% increase in the gravity loading and therefore stress on the existing roof framing. Load case before and load
case after solar panels have been added have both been considered according to Minnesota State Building Code
1607.13.5.1.
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 5 of 7
Array 3
Array Details
Roof Framing Pre-Manufactured
Truss
Spacing 24.0"
Beam Span 13.0'
Roof Pitch 34°
Panel Quantity 2
Panel Array Area 43.27 ft²
Panel Orientation Portrait
Lag Screw Embedment 2.5"
Roof Attachment Type Anchor Foot 5/16” lag
screw
Shear Capacity
NDS 190.0 lbs
Pullout Capacity
NDS 665.0 lbs
Velocity Pressure
Equation 26.10-1 (Kz=0.9, Kht=1,
Kd=0.85, Ke=0.97)
22.54 psf
GCP Zones 1/2e/
2r 2n/3r 3e
GCpFigure 30.3-(2A-5B)-1.8 -2.0 -3.2
Design Pressure Up [psf]
Equation 29.4-7 ga=0.49 gE=1.0,-20.0 -22.2 -35.6
Factored Design Pressure
Up [psf]
ASD LC (.6D + .6W)
-10.7 -12.0 -20.0
Exposed Design Pressure
Up [psf]
ga=0.49 gE=1.5,
-30.0 -33.4 -53.4
Design Pressure Down
[psf]8.9 8.9 8.9
Tributary Area [ft2]12.3 12.3 12.3
Maximum Connection
Spacing [in]47 47 47
Maximum Rail Span [in]48 48 48
Maximum Rail Cantilever
[in]8 8 8
Design Connection
Spacing [in]24 24 24
Deign Connection Spacing
(exposed) [in]24 24 24
Prescriptive Method: Minnesota Conservation Code for Existing Buildings Code 806.2
Total load on member without solar 1472.62 lbs
Total load on member with solar 1298.81 lbs
Percentage of total design load on member with solar 0.88%
The 2020 Minnesota Conservation Code for Existing Buildings section 806.2 indicates that alterations to an existing
building that results in less than a 5.0% increase in the total stress may be performed without a structural evaluation of
the existing building. As demonstrated in the above calculations, the additional weight of the solar panels will be less
than 5.0% increase in the gravity loading and therefore stress on the existing roof framing. Load case before and load
case after solar panels have been added have both been considered according to Minnesota State Building Code
1607.13.5.1.
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 6 of 7
Array 4
Array Details
Roof Framing Pre-Manufactured
Truss
Spacing 24.0"
Beam Span 17.0'
Roof Pitch 34°
Panel Quantity 4
Panel Array Area 86.54 ft²
Panel Orientation Portrait
Lag Screw Embedment 2.5"
Roof Attachment Type Anchor Foot 5/16” lag
screw
Shear Capacity
NDS 190.0 lbs
Pullout Capacity
NDS 665.0 lbs
Velocity Pressure
Equation 26.10-1 (Kz=0.9, Kht=1,
Kd=0.85, Ke=0.97)
22.54 psf
GCP Zones 1/2e/
2r 2n/3r 3e
GCpFigure 30.3-(2A-5B)-1.8 -2.0 -3.2
Design Pressure Up [psf]
Equation 29.4-7 ga=0.49 gE=1.0,-20.0 -22.2 -35.6
Factored Design Pressure
Up [psf]
ASD LC (.6D + .6W)
-10.7 -12.0 -20.0
Exposed Design Pressure
Up [psf]
ga=0.49 gE=1.5,
-30.0 -33.4 -53.4
Design Pressure Down
[psf]8.9 8.9 8.9
Tributary Area [ft2]12.3 12.3 12.3
Maximum Connection
Spacing [in]47 47 47
Maximum Rail Span [in]48 48 48
Maximum Rail Cantilever
[in]8 8 8
Design Connection
Spacing [in]24 24 24
Deign Connection Spacing
(exposed) [in]24 24 24
Prescriptive Method: Minnesota Conservation Code for Existing Buildings Code 806.2
Total load on member without solar 1878.86 lbs
Total load on member with solar 1357.44 lbs
Percentage of total design load on member with solar 0.72%
The 2020 Minnesota Conservation Code for Existing Buildings section 806.2 indicates that alterations to an existing
building that results in less than a 5.0% increase in the total stress may be performed without a structural evaluation of
the existing building. As demonstrated in the above calculations, the additional weight of the solar panels will be less
than 5.0% increase in the gravity loading and therefore stress on the existing roof framing. Load case before and load
case after solar panels have been added have both been considered according to Minnesota State Building Code
1607.13.5.1.
581 E Technology Ave, C1500 | Orem, UT 84097 | 925-787-3067 | www.rightangleeng.com | Page 7 of 7