Correspondence ION Solar
4801 N University Ave Suite 900
Provo, UT
luke.rowley@ibnsofar.rom "
Monday,June 27, 2022
RE: Emily H &Andrew M Mesa Residence- 11874 Southwest Penny Lane,Tigard, Oregon
To Whom It May Concern:
I have evaluated the roof structural elements of the residence for the required design loads and the additional load that
will be imposed by the proposed solar system.The existing roof information was provided by a site visit by an audit team
at ION Solar. Based on that site visit, it is my understanding that the roof framing information is as follows:
Roof Structure: Pre-Manufactured Wood Trusses with 2x4 Top Chords @ 24" O.C. that appear to be
in good working order.
Roofing Material: Composition Shingle
The Required codes and loads are as follows:
Codes: 2019 OSSC,2021 ORSC
Risk Category: II
Wind Speed (3-Sec Gust, MPH): 96
Exposure Category: C
Ground Snow Load (psf): 25
Roof Snow Load (psf): 25
Roof Live Load (psf): 20(superseded by roof snow load)
After reviewing the existing roof framing information and in accordance with the structural calculations on sheet S-5
which were performed according to the applicable codes and loads above, it is my recommendation that the existing roof
framing is adequate to safely and sufficiently support the required structural design loads and the weight of the new solar
system as is.Alteration or replacement of existing structural elements is not required.
This evaluation only applies to the areas of the roof that will be directly supporting the solar system and does not make
any recommendations for any other structural components of the building.The racking must be installed per the
manufacturer's recommendations.
The 5/16"x 3-1/2" zinc plated steel lag screw used to attach the solar system to the roof must be staggered to evenly
distribute the loads over the affected area and must penetrate the truss top chords with a minimum embedment depth
of 2.5" P ROt-e,
I Nr ,),P/, THIS LETTER VOID UNLESS STAMPED
Sincerely,
A. Luke Rowley, PE 9 950P
OREGON
9�qN 11, 2� y 06/29/2022
N R0`N
EXPIRES:12/31/24