Fire rated assembly for structural members

[nealderidder]

This may be old ground but here goes...

Stair enclosures (1022) are required to be fire barriers and allowable penetrations per 1022.5 are scant. My engineers are always sending me details that penetrate that interior gyp. bd. membrane to bear structure (like channels for landings) on columns within the walls.

I try to shoo them out of the walls, they say they need lateral bracing. We wind up showing a detail where the penetration thru the wall is minimized and we hope nobody asks us to provide a listed rated assembly.

So the question is - what is you S.O.P. for stair landings in rated enclosures? And... are there actually any listed assemblies for structural members penetrating fire barriers? You can't swing a cat without hitting a listed assembly for wires, ducts, pipes, and etc. but where are the listed assemblies for steel channels?

714.3.2 points me to 714.3.1.1 (this is California) which says any penetration needs a rated assembly. Usually some red goo around a half dozen bolts that connect the landing rim to something in the wall is enough but is it a rated assembly?

Thanks,

Neal

 

[nealderidder]

Hello? I usually learn so much in this forum and look forward to a great conversation. No one wants to give their two cents? Was the question just too stupid to respond to?

 

[cda]

Slow time of the year

 

[mtlogcabin]

My engineers are always sending me details that penetrate that interior gyp. bd. membrane to bear structure (like channels for landings) on columns within the walls.

Does a shaft enclosure for an exit stair need to be rated from both sides?
Find an assembly that is rated from the exterior side of the shaft. GA WP 7125 comes to mind and I believe you can find other options where the interior membrane is not part of the fire assembly.

 

[cda]

Not an IBC person, engineer, structural

But appears no actual penetrations are allowed into the actual stairwell

But appears can be into the wall assembly, as long as properly fire stopped ??

 

[RLGA]

There are no tested assemblies for a steel structural member penetrating the membrane of a fire-resistance-rated assembly. This is where IBC Section 104.11 comes in handy. I'd submit an alternative design based on Section 714.3.2, Exception 1. If the penetrating steel member is less than 16 sq. in. in area and there are no more than 100 sq. in. of penetrations in 100 sq. ft. of wall, then a steel member penetrating a membrane should be no different than an electrical box doing the same thing, provided one of the five separation methods are used.

 

[nealderidder]

Nice RLGA. And that's what is so great about this forum.

I'm still curious how everyone handles this (with framed walls). Do we all just keep the penetrations (supporting stair landings) to a minimum and hope we don't get asked for a listed assembly? I find it hard to believe everyone is using "Alternative" solutions.

I guess the easy way, like for elevators, is to build the enclosure out of CMU or concrete...

Thank you,

Neal

 

[my250r11]

Seen some with clips installed first, the wall finished and then either bolted or welded, also done a couple with 4 support columns for the landings inside the enclosure, and the stairs attached to the floor at each level for the the lateral support.

 

[steveray]

Here is an interp from our state office:

http://www.ct.gov/dcs/lib/dcs/offic...files/formal_interpretations/2009/i-06-09.pdf

Most of ours are masonry and less of a deal, but as always Ron has some great advice...Which I am probably about to use in my new wood frame apartments...