HomeMy WebLinkAboutC_08-14-20 Plan Review Letter from Al_v1
August 14, 2020
Ms. Karen Lang
212 South 20th Place
Renton, WA 98xxx
RE: Building Permit Structural Plan Review – Prescreen Submittal
212 S 20th Place – Deck (Code 20-000309)
Dear Ms. Lang:
We performed a prescreen of the proposed project for compliance with the structural
provisions of the 2015 International Residential Code (IRC) and 2015 International
Building Code (IBC) as amended and adopted by the state of Washington and the City
of Renton. The design team should address the comments below.
We recommend that the permit applicant have the geotechnical engineer, architect,
and structural engineer respond and resubmit for additional review.
All information should be submitted directly to the City of Renton.
Geotechnical
1. Due to building on the sloping ground, the geotechnical engineer should submit
a report or letter including total and differential settlements, slope instability
and remediation measures, and the allowable soil load-bearing pressure. It is
our understanding that slope may be of questionable quality. See IRC Sections
104.1 and 106.1 as well as IBC Sections 104.1, 1603.1.6, 1613.3.2, 1803.5.11,
and 1803.5.12.
2. If an allowable soil load-bearing pressure exceeding 1,500 psf was used in the
design of the proposed structure, then the City of Renton requires a
geotechnical evaluation be submitted to support using an allowable soil load-
bearing pressure exceeding 1,500 psf. Please submit such a geotechnical
report or revise the design to show the proposed structure does not exceed the
1,500 psf loading threshold. See IRC Sections 104.1 and 401.4.
Ms. Lang
Page 2 of 4
August 14, 2020
Architectural
1. Please submit a site plan so that a review of structure’s requirements with
respect to fire resistance requirements may be determine. If the proposed
structure is less than 5 feet from the property line then by IRC Table 302.1(1),
the structure should be constructed to have a 1-hour fire resistance rating in
accordance with ASTM E119 or UL 263. See IRC Section 106.1.1.
Structural
General
1. The drawings do not indicate climatic or geological information (i.e.; ground
snow load, wind, seismic design category, frost line depth, etc.…). The
drawings should be revised to include this information and resubmitted for
review. See IRC Sections 106.1.1 and 301.2 and Table 301.2(1) as well as IBC
Section 2308.1.
2. Please submit substantiating data, such as additional documentation, that
fasteners installed in preservative-treated wood were be hot-dipped zinc-
coated galvanized. This includes nuts and washers. Fasteners other than nails
and timber rivets are permitted to be mechanically deposited zinc-coated with
coating weights complying with ASTM B 695, Class 55 minimum. See IRC
Section 317.3.
3. Our review of drawings indicate there are non-prescriptive structural details
(details beyond those give in the 2015 IRC). For those sheets with these details,
the sheets need to include the stamp and signature of the engineer of record.
Please revise these sheets to include the engineer’s stamp and signature and
resubmit for review. See the Washington Administrative Code Sections 196-23-
010 and 196-23-020 (especially with respect to “Final documents”).
4. Please submit in drawings indicating the connection details to allow for a
review. The current drawings set does not detail the connections. The revised
drawings should be resubmitted for review. See IRC Sections 106.1.1 and 301.1
as well as IBC Sections 107.2.1 and 1604.2.
Ms. Lang
Page 3 of 4
August 14, 2020
5. Please submit drawings indicating the grade of species of lumber used to
construct the proposed deck. See IRC Sections 104.1 and 106.1.1.
Foundation
6. Please submit calculations showing the proposed foundation system has design
the capacity to resist the required dead and live loads. See IRC Section 301.1 as
well as IBC Section 1604.2.
7. Please submit drawings that show the proposed foundation system so that a
review of system including its connections may be preformed. See IRC Sections
106.1.1 and 301.1.
8. Follow the above comment, please explicitly indicate the minimum frost depth
of the proposed foundation. Our review indicates the minimum frost depth to
be a minimum of 12 inches. See IRC Sections 106.1.1 and 301.1 as well as see
https://edocs.rentonwa.gov/Documents/0/edoc/956006/Climatic%20design%2
0criteria.pdf and the “Climate and Geographic Design Criteria” under the New
Single Family Home section for further information.
Vertical
9. Please submit calculations showing the proposed deck has the design capacity
to resist the required dead and live loads. Note that per the State amended
Table R301.5, the deck shall be designed for a minimum of 60 psf live load. See
IRC Sections 106.1.1 and 301.1 and the State amendments to the Residential
Code in https://fortress.wa.gov/ga/apps/sbcc/Page.aspx?nid=14 as well as
Interpretation 16-11 in
https://fortress.wa.gov/ga/apps/sbcc/Page.aspx?nid=75.
Lateral
10. Please submit lateral calculations which show the proposed deck and its
supports have the design capacity to resist wind/seismic uplift and seismic
forces, especially with respect to seismic pounding of the proposed deck to the
existing structure. See IBC Section 1604.2 and 1613.1 as well as ASCE 7-10
Table 12.12.3.
Corrections and comments made during the review process do not relieve the permit
Ms. Lang
Page 4 of 4
August 14, 2020
applicant or the designers from compliance with code requirements, conditions of
approval, and permit requirements; nor are the designers relieved of responsibility for
a complete design in accordance with the laws of the state of Washington. This review
is for general compliance with the International Residential Code and International
Building Code as they relate to the project. See IRC Section 105.4.
If you have any questions or need additional clarification, please contact us.
Sincerely,
Alan D. Findlay, P.E.
Building Plan Reviewer, City of Renton
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