HomeMy WebLinkAboutReport ms-r 2023- 001 oz. 'FIVE .
City of Tigard 1 „R z / 2023
114 '' Building Division CITY OF TIGARD
• 13125 SW Hall Blvd,Tigard, OR 97223 BUILDING DIVISION
Phone: 503.718.2439 Fax: 503.598.1960
TIGARD Inspection Line: 503.639.4175
www.tigard-or.gov
2010 Oregon Solar Installation Specialty Code
Check List for Prescriptive Installation of Roof-Mounted
PhotoVoltaic Solar Panel System
Property Information
Installation Address: 15315 SW Alderbrook Dr
City: Tigard Zip: 97224
Owner's Name: Richard Garber Date: 3/21/23
Contractor's Name: Blue Sky Solar CCB #: 223739
Design Parameters of the Property/Structure
If"Yes", does not
Flood Hazard Is the installation ❑ Yes qualify for the
Area Located in a flood prescriptive path, follow
plain/flood way? ,' No OSSC or ORSC for
desk requirements.
Is the wind exposure Yes If"Yes", qualifies for
Wind Exposure "c"or less?
❑ No the prescriptive path.
Installations on detached Is the Ground Snow
single/two-family Load 70 psf or less?
dwelling/single/two- If"Yes", qualifies for
family townhomes .er Yes the prescriptive path.
and/or their accessory
Ground structures. ❑ No
Snow Load Is the Ground Snow
Installations on all Load 50 psf or less?
If"Yes", qualifies for
structures other than
❑ Yes the prescriptive path.
above
❑ No
1
I:/Building/Forms/Photo V oltaic-Checklist02.01-11.docx
Is the construction Yes
material wood and does
Type of If"Yes", qualifies for
the construction qualify
Construction as "conventional light ❑ No the prescriptive path.
frame" construction?
Is the spacing 24 inches
or less?
Pre-engineered trusses. 12. Yes If"Yes", qualifies for
the prescriptive path.
❑ No
Roof framing
members Is the spacing 24 inches
or less?
If"Yes", qualifies for
Nominal lumber.
E Yes the prescriptive path.
E No
Is the combined weight o Yes
of the PV modules and If"Yes", qualifies for
racking less than or E No the prescriptive path.
Solar equal to 4.5 psf?
installation Is the solar installation
layout in accordance Yes
with Section 305.4(3) of If"Yes", qualifies for
the 2010 Oregon Solar ❑ No the prescriptive path.
Code?
0 Metal
Single layer If roofing material is
Roofing Check the type of 0 of wood one of the three types
material roofing material shingle/shake checked, qualifies for
Max. two layers the prescriptive path.
of composition
shingle.
Is the roof mounted /Yes
Connections of solar assembly
the solar assembly connected to roof If"Yes", qualifies for
to the roof framing or blocking ❑ No the prescriptive path.
directly?
2
t113uilding/Fortes/PhotoVoltaic-ChecklistD2-01-11.docx
Is the gauge 26 or less?
If"Yes", qualifies for
❑ No the prescriptive path.
115 lbs for 60 inch
spacing or less?
If"Yes", qualifies for
Yes the prescriptive path.
❑ No
Minimum Uplift rating
of Clamps? 75 lbs for 48 inches
spacing or less?
If"Yes", qualifies for
S Yes the prescriptive path.
❑ No
Attachment of
roof mounted Minimum 24 inches If the spacing falls
solar systems Spacing of clamps? within 24 inches and 60
directly to inches Maximum 60 inches inches, qualifies for the
standing seam prescriptive path.
metal panels Width of roofing If the width of the panel
panels? 18 inches or less is less than 18 inches,
inches qualifies for the
prescriptive path.
Minimum#10 at 24
inches o/c?
Size and spacing of If"Yes", qualifies for
rde
fastener? Yes the prescriptive path.
❑ No
Is the roof decking of
WSP min. '/"thickness, Yes
decking connected to If"Yes", qualifies for
framing members ❑ No the prescriptive path.
w/min. 8d nails @
6"/12" o/c?
Is the height less than or
Maximum 18 inches equal to 18 inches?
Height of the from the top of the If"Yes", qualifies for
solar modules module to the roof Yes the prescriptive path.
surface. r No
3
I:fBui I dingfForms/PhotoVoltaic-Checkl ist02-01.11.doex
Submittal Documents required for Prescriptive Installations
Show the location of the PV system in relation to buildings, structures,
property lines, and, as applicable, flood hazard areas.
Site Plan Details must be clear and easy to read.
Minimum size of the plan is 8.5 x 11 inches.
Attach a simple structural plan showing the roof framing (rafter size, type, and
spacing) and PV module system racking attachment.
System must be shown in sufficient detail and clarity to assess whether it
Structural Plan meets the prescriptive construction requirements as listed earlier above in the
matrix.
Minimum size of the plan is 8.5 x 11 inches.
PV Modules
Manufacturer: REC Solar
Model Number:
Listing Agency: REC Solar/ Blue Sky Installing
4
I:Building/Forms/PhotoVoltaic-Checklist02.01-11.docx
W .SSUNG RECEIVED
• �+• MAR 2 / 2023ONSULTING
76 North Meadowbrook Drive
Scott E. Wyssling, PE Alpine, UT 84004
Coleman D. Larsen, SE, PE CITY OF TIGARD office (201) 874-3483
Gregory T. Elvestad, PE BUILDING DIVISI,flgfssling@wysslingconsulting.com
March 16, 2023
Blue Sky Solar LLC
1550 West Gordon Avenue
Layton, UT 84041
Re: Engineering Services
Garber Residence
15315 Southwest Alserbrook Drive, Tigard, OR
6.000 kW System
To Whom It May Concern:
We have received information regarding solar panel installation on the roof of the above referenced
structure. Our evaluation of the structure is to verify the existing capacity of the roof system and its ability
to support the additional loads imposed by the proposed solar system.
A. Site Assessment Information
1. Site visit documentation identifying attic information including size and spacing of framing
for the existing roof structure.
2. Design drawings of the proposed system including a site plan, roof plan and connection
details for the solar panels. This information will be utilized for approval and construction
of the proposed system.
B. Description of Structure:
Roof Framing: Prefabricated wood trusses at 24" on center. All truss members are
constructed of 2x4 dimensional lumber.
Roof Material: Composite Asphalt Shingles
Roof Slope: 20 degrees
Attic Access: Accessible
Foundation: Permanent
C. Loading Criteria Used
• Dead Load
o Existing Roofing and framing = 7 psf
o New Solar Panels and Racking = 3 psf
o TOTAL = 10 PSF
• Live Load = 20 psf(reducible)—0 psf at locations of solar panels
• Ground Snow Load = 36 psf
• Wind Load based on ASCE 7-16
o Ultimate Wind Speed = 96 mph (based on Risk Category II)
o Exposure Category C
Analysis performed of the existing roof structure utilizing the above loading criteria is in accordance
with the 2022 Oregon Structural Specialty Code, including provisions allowing existing structures
to not require strengthening if the new loads do not exceed existing design loads by 105% for
gravity elements and 110% for seismic elements. This analysis indicates that the existing framing
will support the additional panel loading without damage, if installed correctly.
•Page 2 of 2
D. Solar Panel Anchorage
1. The solar panels shall be mounted in accordance with the most recent Unirac installation manual.
If during solar panel installation, the roof framing members appear unstable or deflect non-
uniformly, our office should be notified before proceeding with the installation.
2. The maximum allowable withdrawal force for a 5/16" lag screw is 298 lbs per inch of penetration as
identified in the National Design Standards (NDS) of timber construction specifications. Based on
a minimum penetration depth of 2'/2", the allowable capacity per connection is greater than the
design withdrawal force (demand). Considering the variable factors for the existing roof framing
and installation tolerances, the connection using one 5/16" diameter lag screw with a minimum of
2'%"embedment will be adequate and will include a sufficient factor of safety.
3. Considering the wind speed, roof slopes, size and spacing of framing members, and condition of
the roof, the panel supports shall be placed no greater than 48" on centers.
Based on the above evaluation, this office certifies that with the racking and mounting specified, the existing
roof system will adequately support the additional loading imposed by the solar system. This evaluation is in
conformance with the 2022 Oregon Structural Specialty Code, current industry standards, and is based on
information supplied to us at the time of this report.
Should you have any questions regarding the above or if you require further information do not hesitate to
contact me.
Very truly yours,
4,
'•-9 0 ,- ��D PROFF
Scott E. Wy--i g, • �5� %NF ' S'i,,a
`
Oregon Li, nse • •'•:01
1/ 'Ec .
c
/i,
°rr E. wr55`•`
Signed: 3/16/2023