Exterior Egress - NFPA 253 applies?

Archive of Older Topics Archive - Specifications Discussions #5
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Hello,

This is more of a code question than a spec question probably, but I thought I’d write it up here in case anyone might know the answer.

I am working on a small residential project in Kentucky (2012 IBC, essentially). It’s a 13R sprinklered building that has a double-loaded, exterior corridor. Four units per floor, and two exterior stairs (one on either end of the corridor).

Our setup for the code analysis essentially follows the logic determined in this thread (thanks to Bill Foster for the info here):

http://www.iccsafe.org/iccforums/pages/default.aspx?action=ViewPosts&fid=11&tid=24398&page=1

I was wondering if anyone knew whether the Radiant Flux requirements for the flooring (IBC section 804.4) applies in an exterior egress system such as this? The code continually references interior finishes, but also mentions “… floor covering materials in exit enclosures, exit passageways, corridors…” must meet the critical radiant flux (NFPA 253). We’re hoping to use a composite lumber in these walkways, but I can’t find any testing data for these materials. (I find plenty of flame spread, ASTM E-84 data, but no NFPA 253 data)

Any help on either the interpretation of this code section, or it’s applicability would be greatly appreciated.

Many thanks

Luke Field

www.citystudiosarch.com

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Luke:

The open ended corridor is a corridor per Section 1018, so, in essence, the requirements for floor finishes in Section 804 would apply.

However, Section 804 generally applies to fiber-bearing floor covering systems, such as carpet. The exception to Section 804.1 allows “traditional type” flooring to be exempt. They list some examples, but the use of of the phrase “such as” does not limit the exception to only those materials listed.

The IBC Code and Commentary states, “Smooth surface floor coverings generally contribute minimally to a fire. The focus is more upon textile floor coverings, such as carpets.”

Therefore, I would consider the composite lumber to be wood flooring (i.e. smooth, hard surface) and not subject to the requirements of NFPA 253.

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Ronald,

Thank you for the reply - this helps to clarify the intent greatly.

Many Thanks,
Luke Field