From: Charles Espenlaub <Cespenlaub(--nospam--at)martinaia.com>
Date: Wed, 28 Jun 2000 10:28:35 -0400
The Architect is responsible for determining required rating for
assemblies, etc. However, you also need to be involved. Type II is
non-combustible, so wood as a structural element is not allowed (I am
not 100% sure about heavy timber though). Eventhough the Architect
chooses fire ratings, his choices will affect your design. If you've
masonry walls, you may need 2,3 or 4-hour rated block. If this is the
case, you need to call for this on the structural drawings, otherwise
the contractor will probably miss it. The higher the rating, the higher
percent solid the block needs to be. Also be ware; the average
thickness requirements for a given rating vary for UL, SBC, and NCMA TEK
notes. UL is the most restrictive, and their requirements need to met
if the Architect is using the cmu in an UL assembly.
If you are using steel, most likely the architect will protect the steel
with spray on fire proofing, or encasement in gypsum sheathing. Here
you need to know what UL assembly he is using, as they often require
minimum sizes (read generally minimum weight per foot). So even though
you may only need a W8x10 for that little span, to meet the assembly
requirements, you may have to use a W8x18, or larger.
With concrete, the required fire rating will drive the minimum thickness
or size of members, as well as the minimum cover to the reinforcing.
The minimum thickness, size, and/or cover will depend not only on the
rating required, but also on the type of aggregate used.
It is best to get with the Architect early in the project, and see what
requirements affect you. At that point they are easy to design around.
Later on it can cause you both problems (such as trying to fit the 10"
concrete column where everyone had planed for an 8" column).
Charles F. Espenlaub, III, P.E.
From: Michael Zaitz [mailto:mzaitz(--nospam--at)hgbd.com]
Sent: Monday, June 26, 2000 10:44 AM
Subject: Fire Protection
We have a building which is required to be Type II construction per the
Building Code. This requires the structural members to have fire
ratings from 2
to 4 hours depending on the member. I have not done a building that
Fire Protection at this level. My questions are:
Who's responsibility is the Fire Protection? Ours, the Architect's or
Are there any good references out there on this subject?
I understand that there are prorated assemblies for fire rating. Is
published by the Underwriter's Laboratory (UL)?