From: "Sprague, Harold O." <SpragueHO(--nospam--at)bv.com>
Date: Fri, 3 Mar 2000 12:27:50 -0600
Tarno Coleman and I had an off line discussion about penetrations of fire
walls. I thought that the thread might prove to be informative to the
Tarno pointed out the distinction between area separation walls and
occupancy separation walls.
From: TARNO COLEMAN [SMTP:TCOLEMAN(--nospam--at)OPENGOVT.OPEN.ORG]
Sent: Wednesday, February 23, 2000 1:31 PM
Subject: Re: RE: Area separation walls.
The code has many different requirements that specify fire resistive
construction. Different types of separations (occupancy; area;
specific) may have the same hourly fire-resistant and can result in
confusion. All walls with a equal fire-resistance hourly rating are
not necessarily the same for code purposes. An area separation wall
a special critter. Exit enclosures are an example of specific
requirements for stairway protection.
The following is from the 1997 UBC and the 1997 UBC Handbook:
1997 UBC Volume 1
"504.6 Area Separation Walls.
504.6.1 General. Each portion of a building separated by one or more
area separation walls that comply with the provisions of this
may be considered a separate building. The extent and location of
area separation walls shall provide a complete separation.
When an area separation wall also separates occupancies that are
required to be separated by an occupancy separation, the most
restrictive requirements of each separation shall apply."
1997 UBC HANDBOOK
"504.6 Area Separation Walls. In Section 302 the code introduced the
concept of the fire-resistive separation, designated the "occupancy
separation," where the openings in the separation wall are protected
by fire-protection assemblies. The Uniform Building Code has a
type of fire-resistive separation, which is called the "area
separation wall." The intent of the code is that the function of the
wall is exactly as its name implies-a vertical wall that separates
areas. This is to distinguish it from an occupancy separation that
be horizontal. Structural members that penetrate area separation
could limit the effectiveness and would not comply with the
that states such walls "shall provide a complete separation." Any
member that passes through an area separation wall could affect the
integrity of the required fire-resistive construction. However, the
code does not prohibit western platform framing to divide a two-hour
area separation wall if solid blocking is provided within the floor
roof cavity. See Footnote 2 for a reference to an article by Paul
Sheedy which illustrates this concept." (emphasis added)
>>> "Sprague, Harold O." <SpragueHO(--nospam--at)bv.com> 02/23/00 08:38AM >>>
I have often seen stairwells in buildings with rated enclosures that
had to be sealed at the top to prevent smoke from entering the stair
enclosure. Or another one was a small office adjacent to a
facility. The roof structure went through uninterrupted. They were
referred to as area separation walls. This is very common in the
metal building industry.
Is this a correct interpretation?
> -----Original Message-----
> From: TARNO COLEMAN [SMTP:TCOLEMAN(--nospam--at)OPENGOVT.OPEN.ORG]
> Sent: Wednesday, February 23, 2000 10:33 AM
> To: SpragueHO(--nospam--at)bv.com
> Subject: Area separation walls.
> Excuse the off-line reply, but our mail system does not permit
> to the list.
> Our interpretation of the UBC regarding area separation wall is
> no structural members pass through it. The logic being if the
> fails on the fire side it may pull the wall apart.
> As an alternate method on one job, we accepted 2-hour protection
> beams and columns supporting the beam that passed though the area
> separation wall. (sismic tie) This building was fully sprinklered.
> ps: I appreciate your thoughtful and incisive responses to the
> Tarno Coleman, PE
> Plan Check Engineer
> e-mail: tcoleman(--nospam--at)mail.open.org
> Marion County Building Inspection
> PO Box 14500, Salem, Oregon 97309