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Fire proofing joist hanger?

mtlogcabin

mtlogcabin

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I have 3 story R-2, V-A building with a NFPA 13R system, 2006 IBC

There are some steel columns and beams the I-joist floor system will be hanging from using top flange hangers. The contractor was informed by the fire spray applied fire proofing contractor that the I-Joist hangers need to be fire proofed also since they are steel. The GC is asking if this is required now. Never heard of having to do this.
 
thinking outloud without benefit of code article.

5A construction requires rated floor / ceiling assembly of 1 hour

rated construction assemblies require SUPPORT to match assembly supported,

hanger supporting assembly should be inside a listed assembly (listing support method as hangers)
 
Architect1281 said:
thinking outloud without benefit of code article.5A construction requires rated floor / ceiling assembly of 1 hour

rated construction assemblies require SUPPORT to match assembly supported,

hanger supporting assembly should be inside a listed assembly (listing support method as hangers)
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I could be wrong, but for some reason I doubt that typical hangers are part of any spray fireproofing listing.
 
The joist hangers are the supporting member for the joists - can the joist hangers be removed and the joist remain supporting the load(s) they are carrying? Some form of protection should be used -

No problem if covered by gypsum board - but open bays could be an issue.

JMHO
 
Think about it-- the hangers are supporting I-Joists

The bare steel hanger's fire resistance is several times that of the I-Joist it is supporting About 20 minutes vs 5 minutes

The gypsum board protecting the I joists will provide adequate protection for the hangers.

Spray on fireproofing would not be effective on sheetmetal joist hangers as these systems depend on the mass of the steel as a heat sink--hence the minimum member size in each listing.

The gypsum board provides its own heat sink.
 
The bare steel hanger's fire resistance is several times that of the I-Joist it is supporting About 20 minutes vs 5 minutes
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That is what The GC and I where thinking. the I-Joist would fail before the hangers.

All of this is in a 1-hour fire rated floor ceiling assembly, nothing is exposed
 
"All of this is in a 1-hour fire rated floor ceiling assembly"

Bingo, does the listed 1-hour assembly show the condition? If it's part of the assembly then.........

Sounds to me like the spray applied contractor is looking for a few more bucks, pay for the summer vacation, ya know?
 
The only question I have is - Is the building a designed building by an engineer? If so you're answer is easy - what does the engineer require and what will he affix his stamp to. If it's not an engineered building then this isn't the answer you were looking for.
 
mmmarvel said:
The only question I have is - Is the building a designed building by an engineer? If so you're answer is easy - what does the engineer require and what will he affix his stamp to. If it's not an engineered building then this isn't the answer you were looking for.
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Plan review by Braille.
 
It is an engineered building. The problem lies with the monocoat manufacturer will not sign off on the fire proofing of the beam if the joist hangers are not covered unless the AHJ says it is ok. If this was a heavy timber wood beam in lieu of steel the question never would have come up. BTW steel package fabrication is complete and will ship next week so it is to late to change. All the listed assemblies I have looked at never show a floor connection to a beam or wall. They all bear on top of the supporting construction
 
The building official still needs to check the building for compliance even if an engineer designed the building.

This points out one of the problems with the concept that if the item is not in the fire test assembly that it cannot be used. If you were strict in enforcing this interpretation I expect that you could come to the opinion that no wood building would comply. We would then find that all manufacturers of joist hangers would have to perform fire tests with there products used in all of the assemblies. We would probably need a different series of fire tests for different styles of hangers for each manufacturer. This would make UL rich and increase the cost of construction.

Given that the I-joists have such a low fire rating without the ceiling and the reality that the joist hangersprobably have as good or better rating than the I-joists I suggest they can be used without being listed in the assembly.

I believe that this approach is supported by experience. There are a lot of fires in wood buildings and if the joist hangers were the weak link in the system I would expect that this would have been identified as a problem.

It is my belief that if we applied a strict literal interpretation to the code we could legally stop all construction.
 
The problem lies with the monocoat manufacturer will not sign off on the fire proofing of the beam if the joist hangers are not covered unless the AHJ says it is ok.
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That's bull-puckey. The word of the AHJ won't make their product perform any differently. If they are concerned about the performance of their product, they should simply say that the hangers need to be sprayed.

My first inclination is to agree with the others and say that if concealed within the rated assembly, then no problem; however, I won't do that if the fireproofing folks are going to put the potential for failure on me. No way.
 
permitguy said:
however, I won't do that if the fireproofing folks are going to put the potential for failure on me. No way.
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Thanks for reminding us all of two important sections of the code: The one which says "The AHJ shall limit his liability regardless of what the code requires," and of course the one which says "Subcontractors shall determine the applicability of all code provisions."
 
Where in the code does it require that the firproofing contractor sign off on the installation? There is a requirement for special inspection of the fireproofing by a special inspector hired by the Owner. The nature of the special inspections called for by the IBC do not address the composition of the assembly.

Ignore the contractor and ask the Owner to provide the required special inspections.
 
If it's a listed, tested assembly, and it complies wth the listing, a special inspection is not necessary.
 
Fatboy

IBC Section 1704.12 requires special inspection even if it is part of a listed assembly.
 
Bruggers I agree that is why I mentioned enclosed within an approved assembly > as a listed / tested support method

I too know of no spay method on a hanger that legitimizes it as rated.

Maybe some of that Magic Intumescent Paint everyone touts these days. (doubtful too)

If it is listed as a portion of something like UL 528 or 529 assembly perhaps .

The same would be true if not on steel but onto a face or top hanger to a Glulam or LVL assembly within a rated assembly.
 
Don't have my IBC at home with me. You are saying that I HAVE to require special inspections for a listed, rated assembly? Could you please post that section requires that? Because we've been screwing it up for years in this jurisdiction, and there's going to be some PO'd designer/contractor/owners when/if I were to start requiring it.
 
mmmarvel said:
The only question I have is - Is the building a designed building by an engineer? If so you're answer is easy - what does the engineer require and what will he affix his stamp to. If it's not an engineered building then this isn't the answer you were looking for.
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MMM As a RDP myself and a CBO I am sometimes appalled at the length of my plan review comments list requesting clarification or inclusion of means methods.

I word it that way cause non-compliace sounds so negative. So leaving it up to the DRP cause they have a stamp and signature is not a winner for me.
 
Couple of observations. MTLC, you have to have special inspections for spray applied fireproofing even if it is a listed assembly. How do you know the fireproofing was applied in compliance with the listing? There are some "outs" that allow you to waive special inspections, but I'd be careful using them.

More to the subject: I would think that the fireproofing contractor is not requiring the fireproofing of the hangers for their protection (since they are protected by gyp. bd.), but is requiring them to be fireproofed because they are hung from the beam, and to not apply fireproofing to them would leave the beam unprotected. Can it be proven that the gyp. bd. envelope provides adequate protection for the beam? If so, why is ANY spray applied fireproofing required?
 
Thanks for reminding us all of two important sections of the code: The one which says "The AHJ shall limit his liability regardless of what the code requires," and of course the one which says "Subcontractors shall determine the applicability of all code provisions."
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The manufacturer of the product is basically saying "this isn't right, but we'll do it anyway if the building official says we can." That is clearly problematic. If you need help understanding why, just ask. No need to get nasty about it.
 
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