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1-hr fire rated wall assembly penetrations

Papio Bldg Dept

Papio Bldg Dept

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Jan 24, 2011
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I have a 1-hr fire rated wall assembly for a corridor that has several light cove details that call for 2x3 exposed wood supports to penetrate the wall assembly in order to attach to the side of the wood stud in the wall assembly. The UL listings provided allow for similar penetrations of metal and plastic piping with fire caulking.

Am I missing something here? Is this compliant?
 
Do you feel a solid wood 2x3 provides as much protection as a listed plastic pipe? If so, the penetration detail should be equivalent.
 
fire stopping

If in any way you deviate from the UL listed system, then it is not compliant to that system. You should be able to contact the manufacturer of the fire stopping material you want to use, tell them your situation, then they can see if they have another system or product that will work. If not they can issue an engineering judgement "EJ". They will look at their systems that are similar and combine 2-3 systems, and basically say in their judgement then it will be a 1hr fire rating.
 
Coug Dad said:
Do you feel a solid wood 2x3 provides as much protection as a listed plastic pipe? If so, the penetration detail should be equivalent.
Click to expand...
That is my basic question. Is a 2x3 equivalent to metal or pvc pipe in the assembly listings? The assembly listings do not say they were tested for this and I have not found one that is, UL, GA or otherwise. When the fire caulk expands it crushes the pipe and seals the penetrations. How does this same principle work for a 2x3 wood member? Does an all wood construction light cove with 2x3 supports penetrating the corridor drywall create enough of a breach in the fire-rated assembly to be non-compliant? In my opinion yes, but is it actually any greater of a fire risk than mounting a ledger mounted light cove over the drywall?

I will see if I can upload some sketches.
 
Papio,

What about using a FRTW and an approved type fire caulking

around the penetration in to the rated assembly (per Section

104.11 - Alternative materials, design and methods of

construction and equipment, 2006 IBC?

.
 
globe trekker said:
Papio,What about using a FRTW and an approved type fire caulking

around the penetration in to the rated assembly (per Section

104.11 - Alternative materials, design and methods of

construction and equipment, 2006 IBC?

.
Click to expand...
Thanks gt. I would definitely feel better about the situation if it was FRTW, however, I do not want to make them do something that is excessive just to make me feel better. As brudgers would say, "how can I approve this detail?" I think me needs more information from the RDP in order to do that.
 
why not look at framing it with a steel member, (light gauge framing members) the same gauge thickness as the pipe wall ( that is ok), citting drywall tight, taping tight firecaulking accordingly. just an idea , now that i've seen the sketch.
 
2009 IBC Section 713.3.2 states that membrane penetrations must meet the requirements of Section 713.3.1 the same as a through penetration. The two options under Section 713.3.1 are Section 713.3.3.1.1 Installed as tested in an approved fire-resistance rated assembly or installed as tested in accordance with ASTM E 814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water and shall have an F rating of not less than the required fire-resistance rating of the wall.

I think in order to penetrate a rated wall membrane with combustible material perscriptively it would have to be Type IV construction otherwise it needs a membrane penetration detail. Looking through the different manufactures of penetration seals and their specification books I did not come up with one as an "off the shelf" application. You may need to do what Sparky suggested and call one of them to get a system for it.

ZIG
 
Let a product manufacturer specify it for you. As a practical matter, a solid wood member would take some time to burn to the point of compromising the wall, FRTW even longer. An intumescent finish on the wood might be a part of a solution. Same concept as the fire caulk, but applied to the surface. There are intumescents out there now that are used to protect steel structures. Looks like gloppy latex paint.
 
Although southern pine has a char rate of 1 1/4 inch per hour, the issue is really having a wooden member penetrating the membrane of a fire rated assembly. This is outside the limitations of the prescriptive means of the code. Either have an "Engineered Judgment" for a fix or don't allow it.

As far as the burn through, that is not the question --- smoke development from a fire is the issue. Please see the below technical paper and you will see why limiting smoke travel in a structure is so important - fire doesn't kill people, the smoke and fire gasses do.

http://www.ul.com/global/documents/corporate/newsroom/storyideas/smokecharacterizationstudy/SmokeStudyTechnicalReport.pdf

A UL and NFPA study on smoke characterization........
 
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I had a similar situation where wood trusses penetrated a rated shaft wall. I sent this to a Fire Protection Engineer as the architect could not find a product tested on wood penetrations. The FPE came back with a detail which required a 6" gyp wrap or the penetrating truss perpendicular to the wall to effectively create a 1 hour burn time for the wood penetrating the wall.
 
Thanks for all of your comments. I have requested more information from the RDP, and will update the post when I have a response.
 
Here is one of the Useful Links that Jeff posted. There's a video about rated penetrations. At least there was. It could be anything by the time you find this. So really... just forget it.

Missouri Association of Code Enforcement
 
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brudgers said:
It's a half assed detail and is non-compliant.
Click to expand...
Details please details....the Devil is in the details and I'll be damned if I know what detail you are referring to.
 
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