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RE: Firewall:(was)CMU Wall Supported by Plyw

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Dave:

You can check out the NCMA Tek 5-8A called Details for Concrete Masonry
Fire Walls.

There might be another NCMA Tek note about firewalls, but I cannot find it
right now.  So, I am not sure if I have the one listed above or if it is
another one (the one listed above was from a search on NCMA's web page).

Hope that helps,

Scott


On Fri, 23 Feb 2001, dcarroll wrote:

> WHAT IS THE MEANING OF         "SNIP"       ????      are you referring to
> some attachment(s) that you inadvertently omitted,  since you only comment
> on one method after you say there are several ways to accomplish the reqd
> result ?
> 
> 
>      I appreciate your comments and am currently developing a study on this
> very subject.    Is there a good treatise on structural design/detailing for
> fire walls???    pls write back - and  thx again
> 
> 
> 
> PS:  Our (Kentucky) SEAOK group is writing a White Paper on Firewalls - does
> ANYBODY out there have some neat, clean details for these animals? I would
> love for you to mail, fax,  or email me
> Pls send to:     David Carroll PE
> c/o   BFM ENGINEERS, Inc        241 Regency Circle,  Lexington, Ky. 40503
> Ph: 859_278-5050 ,,       Fax  859_278-6060
> 
> 
> 
> 
> -----Original Message-----
> From: Roger Turk [mailto:73527.1356(--nospam--at)compuserve.com]
> Sent: Thursday, February 22, 2001 12:32 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Firewall:(was)CMU Wall Supported by Plyw
> 
> 
> Scott Maxwell wrote:
> 
> . > Now about firewalls...
> 
> [snip]
> 
> . > The first thing is to realize that there is a difference between a
> . > firewall and a fire separation wall.  A fire separation wall is a wall
> . > between two spaces that is meant to stop or slow the spread of fire.  A
> . > fire wall is essentially a fire separation wall that MUST remain
> standings
> . > AFTER one side of the building has collapsed (or is one of the two
> . > buildings has collapsed).
> 
> . > If you must have a firewall, then that wall between the two buildings
> must
> . > be designed in a fashion that it would remain standing if either
> building
> . > collapses.  Thus, if the new building falls, then the fire wall MUST
> . > remain standing or if the existing building falls, then the fire wall
> MUST
> . > remain standing.
> 
> . > This can typically be done one of several ways.  You can:
> 
> . > 1) [snip]
> 
> . > 2) Do a single wall that is tied to each structure that has "break away"
> . > connections so that one side can fall without causing the other to
> . > collapse or bringing down the wall.  With a masonry wall with wood
> joists,
> . > this has traditionally been done with a "fire cut".
> 
> . > 3) [snip]
> 
> It seems to me that a "fire wall" would be virtually impossible in seismic
> country as the code requires that the diaphragm be tied to masonry/concrete
> walls.  "Fire cuts" would be ineffective as the joists are tied to the wall
> with "tension ties" or other anchors.  A "fire cut" would only be effective
> for wood joists resting on or in walls without any other type of connection
> between the joist and the wall.  For a fire cut to be effective with tension
> ties, the tension tie would have to be a fusable link and even then it is
> questionable whether that would work, e.g., a fire destroys the wood joist
> at
> mid-span, but does not reach releasing temperature at the fusable link at
> the
> wall.
> 
> A. Roger Turk, P.E.(Structural)
> Tucson, Arizona
> 
> 
> 
>