APPROVED BLD-Structural CalculationsREVIEWED
BY
CITY OF EDMONDS
BUILDING DEPARTMENT
LONGITUDE
ONE TWENTYO
ENGINEERING & DESIGN
STRUCTURAL ENGINEERING SERVICES — Construction Support
Letter created as of the 20th day of January, 2021
1 of 3
RECEIVED
Jan 25 2021
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
Project Name: 7300 176th ST Edmonds —As-Built Deck Review Project Number: S210120-4
Project Location: 7300 176t" ST SW Edmonds, WA 98026 Parcel # 00513600000902
Client's Name: Thang Nguyen (Owner)
Client's Address: 7300 17611 ST SW Edmonds, WA 98026
Dear Mr. Nguyen,
We were asked to visit the city to assess the structural integrity of an as -built exterior deck and stair construction
adjacent to the residence (connected to the structure). We visited the site on the 171h of December, and reviewed
the as -built deck which appeared to be recent construction and estimated to have been constructed within 6
months of our visual observation. We reviewed the deck for gravity components and lateral components, and that
with typical deck loading as prescribed by the currently adopted building code (IBC 2018). The gravity components
included deck joists, support beams, support columns (vertical), and support footings. For the lateral components
we observed the as -built framing to assure that the lateral force resisting system is sufficient to resist the typical
seismic and wind applied loading based on the geometry and weight of the as -built deck.
Response/Repairs as needed:
For the lateral components the system is more than adequate in terms of and the lateral knee -braces
were installed on each of the primary support columns and applied both vertically and horizontally to
further increase the rigidity of the deck diaphragm. However, the connection to columns and beams were
not adequate so we ask that on all knee -braces between columns and beams you install a %" DIA x 8" lag -
screw with a minimum penetration of 4" into each post. (See picture, typical condition needing
strengthening)
For the vertical/gravity components the deck construction complies with assigned demand typical of this
construction, with exception of two posts that will need more significant footings. In both these locations
the slab will need to be cut back and a new 30" x 30" x 12" ftg to be installed w/ (4) #4 rebar (60 KSI,
2,500 psi concrete min), each way in btm of ftg 3" from the underside of footing/soil (3" CLR).
Additionally, the existing columns will need to be connected with the concrete footing w/ minimum
ABU66 or ABU88 by Simpson, and size/type varies per existing post size. (See pictures showing two posts
which will require new footing addition)
The remainder of the deck construction complies with our structural objectives should we have designed
this structure from ground -up, hence we deem the observed components structurally sufficient with the
repairs listed above.
I I,
3 of 3
LONGITUDE
ONE TWENTY°
ENGINEERING & DESIGN
New lag -screws required on all vertical knee braces to post/beams — see report
96
Please let us know if you have any questions. . � i .Ht}*,
•* STRUCTURAL ENGINEER
Sincerely, U" L120 ENGINEERING & DESIGN
*; 13150 91 ST PL NE
Mans R. Thurfjell, P.E. * * �q t�� KIRKLAND, WA 98034
L120 Engineering & design *, s10.NAy ��;*# CONTACT: MANS THURFJELL, PE
mthurfiell@1120engineering.com &. • ' ` * PHONE: (425) 636 3313
EMAIL: MTHURFJELL@Ll20ENGINEERING.COM