Type IiB construction vertical continuity

[aztec]

Hi, i have a simple question and hope someone can direct me to the right code. I have a type IIB construction fully sprinklered and 99% of the 1 hr rated assemblies go from floor to deck. However, i have one wall that is currently dying into the web of a steel beam - right smack in the center. My first thought is this is incomplete, the steel beam must be encased. Is that true? I cant seem to find where the walls must go from slab to deck, not a beam. Single story building, height is 26'. Thanks.

 

[Francis Vineyard]

Assuming 2009 IBC and a Fire Barrier; technically a fire barrier should meet the underside of the roof deck but then T601 roof support is rated zero. Not knowing the size of this configuration it sounds like a case by case basis; what are the odds that the fire will breach over 1 hr. barrier or cause the barrier to fail before the roof decking?

Francis

 

[Builder Bob]

The fire barrier (if such) shall terminate at the roof deck or other rated assembly. A beam is not an rated assembly. The termination at the bottom of the beam does nothing to prevent the spread of smoke as it rises to the roof............ The fire barrier is supposed to resist the passage of fire and fire gasses/smoke. I bet if you took a lift up, you have anywhere from 6 to 10 inch gap above the steel beam.

 

[AegisFPE]

Where a fire-resistance-rated wall terminates at the underside of the flange of an I-beam with the web of the beam parallel to the wall, the issue is that the code requires a wall assembly to pass a fire test with a limited unexposed surface temperature, among other criteria.

Due to the conductivity of steel, we would not expect it to pass the fire test required for a wall assembly.

However, if the purpose of the limited unexposed surface temperature is to prevent the ignition of combustibles on the other side, or provide for occupants to walk adjacent to the assembly without being exposed to extreme heat, there may be a rational approach to justify the subject condition at the roof of a noncombustible building as a modification or alternative to the prescribed code criteria.

 

[Markmax33]

Can you just jog the wall around the beams? You might be able to put in a little horrizonatal piece to put them all on one side of the wall or the other instead of trying to encase them?