fire-resistance rating discussion.pdfMiller, Chuck
From: Miller, Chuck
Sent: Wednesday, June 20, 2018 3:17 PM
To: 'Stacy White'
Subject: RE: BLDs2018-0361/-0619 - Plan Check Comments
The following are responses to your inquiries, as numbered in the most recent comments, regarding the plan review
concerns:
7. Typically, there is great value in indicating those existing elements required to be fire -resistance rated, even on
the `demolition plan'. It lets those doing and inspecting the work that there are elements that might require
additional attention if indiscriminately altered, such as removing the gypsum board without knowing the specifics
of its installation. Since it's apparent that a lot of the demolition work has already been done before the permit
has been issued, in this instance it really doesn't matter if the required fire -resistance rated construction is noted
on the `demolition plan'.
16. `Steel pipe' column - There does not appear to be any provisions for estimated weights... that's why this section is
rarely used for existing conditions where, unlike `new' construction, the specifics of the actual materials used are
difficult to ascertain. Even more troubling is the apparent inapplicability of IBC Figure 722.5.1(3) to `steel pipe'
columns. The IBC appears to only address concrete or clay masonry protected `steel pipe' columns
prescriptively. It's difficult to find many listed, tested assemblies for `steel pipe' columns and the only one with a
>1 to <2 hour rating (UL Design No. X531) also requires the weight of the steel pipe to be known. An
engineering analysis, prepared as described in IBC 703.3, Item 4, is an acceptable alternative the other listed
methods. The `steel pipe' column could also be replaced with a `structural tube' column and be protected by any
of the many available methods.
16. Wood column — There are no listed, tested assemblies for protecting wood columns exposed on all four sides. It
has been determined that a wood column, when enclosed within a fire -resistance rated wall assembly of at least
100 square feet in area with no edge dimension less than nine feet (to match the testing criteria of ASTM E 119 or
UL 263), does not require individual protection. As noted in the earlier plan review comment, if the wood
column is to be exposed/no longer protected with a fire -resistance rated wall assembly, it must be replaced with a
protected steel column.
17. Eliminating that proposal does address that concern.
19. See the responses to `16' above.
Feel free to call me if you have any questions.
Chuck Miller, Senior Plans Examiner
chuck. millerkedmondswa. gov
425-771-0220
'4C. 1 %9'
Development Services Department
Building Division
121 5tb Avenue N
Edmonds, WA 98020
www.edmondswa.vov
Development Services Permit Center Hours
Monday & Tuesday — 8:OOAM — 4:30PM
Wednesday — 8:3OAM — 12:OOPM
Thursday & Friday — 8:OOAM — 4:3OPM
From: Stacy White <stacyw@ankrommoisan.com>
Sent: Wednesday, June 20, 2018 12:17 PM
To: Miller, Chuck <Chuck.Miller@edmondswa.gov>
Cc: Molly Wolf <mollyw@ankrommoisan.com>
Subject: BLDs2018-0361/-0619 - Plan Check Comments
Good morning Chuck,
I'm contacting you regarding Project BLDs2018-0361/-0619. We would like to ensure that we are addressing your
concerns completely in our response; and would like to run a couple of questions past you before resubmitting.
Re: #7 Demolition Plan Keynotes —
We would like to remove detail reference to the final constructed product from this page, as the sheet is specific
to demolition scope of work. We are using the floor plan to guide the contractor to a detail that addresses the
fire -resistance rating requirements of the completed construction. If the necessary information is included on
the floor plan, will that address your concern?
Re: #16 Sheet AO.10 Detail 10, TI Column Surround — existing 3" dia steel columns
We had intended to reference IBC 722.5.1 (3) to address construction criteria for the fire -resistance rated
assembly. You indicate requirement to calculate fire resistance of the column using weight of said column;
though as it is an existing element we are able only to estimate weights. Utilizing the attached formula and
applying values h=.625, D = 1372, W = 25, W1= 322, we arrive at less than 60 for R. If our detail is amended to
reference 722.5.1 (3), will our single layer type X wrap (1 hour containment) address your concern?
722.5.1.2 Gypsum wallboard protection.
The fire resistance of structural steel columns with weight -to heated -perimeter ratios (W/D) less than or equal to 3 65 a
Type X gypsum wallboard shall be permitted to be determined from the following expression
R 130IL "—( 1# 7DJ n
where
R - Fire resistance (minutes)
n Total thickness of gypsum wallboard (inches).
D Heated perimeter of the structural steel column (inches).
W = Total weight of the structural steel column and gypsum wallboard protection (pounds per Nnear fool)
W = W • 501)Dr 144
Re: #16 Sheet AO.10 Detail 10, TI Column Surround — existing wood columns
We would like to indicate similar detail to steel columns, embedding wood structure entirely within 1 hour
containment. Will that approach address your concern?
Re: #17 Sheet A0.11 Interior Partition Types, Detail 4, Partition Head Attached to Suspended Acoustical Ceiling System
We are removing the single instance of that partition from the project, and its associated detail.
Re: #19 Sheet A2.00 Level 2 Floor Plan Keynotes
Our intent is to use a keynote at existing columns to identify rated protection requirements. We intent a
keynote at steel referencing 722.5.1 (3) per #16 above, and a keynote at wood referencing complete
containment within rated wall, sending to appropriate detail on A0.10. Will this address your concerns?
We much appreciate your thoughts as we try to quickly resolve this.
Thank you,
Stacy
Stacy White LEED AP ID+C, NCIDQ, CDT
SENIOR ASSOCIATE / INTERIOR DESIGNER
D) 206.876.3058
Ankrom Moisan Architects, Inc.
ARCHITECTURE INTERIORS URBAN DESIGN BRANDING
1505 5th Avenue / Suite 300 / Seattle, WA 98101
ankrommoisan.com