Fire Treated Timbers Penetrating 2 Hour Walls

[TomFairbourn]

Hello,

In the past we have been able to use a fire treated timber (6x12) to penetrate a two hour shaft (Stair) to use as the landing beam. This is a much easier assembly than typically off set firewall hangers which means I have to build the mid landing and floor landing walls at different heights that interrupt the top plates.

I have used this method on multiple jobs around Salt Lake City, I am currently running into a city that will not allow this because there is no specific UL listing that represents this method. I also cant seem to find anything in the IBC that gives real directive on this issue.

Any information would be greatly appreciated because if this is the case I will also not be able to use fire treated timbers for deck assembly that have the beams supported back in the floor and penetrate the 2 hour exterior walls.

Thanks,

 

[Yankee Chronicler]

Specific in the IBC? IBC 2021:

1023.5 Penetrations. Penetrations into or through interior exit stairways and ramps are prohibited except for the following:
1. Equipment and ductwork necessary for independent ventilation or pressurization.
2. Fire protection systems.
3. Security systems.
4. Two-way communication systems.
5. Electrical raceway for fire department communication systems.
6. Electrical raceway serving the interior exit stairway and ramp and terminating at a steel box not exceeding 16 square inches (0.010 m2).
7. Structural elements supporting the interior exit stairway or ramp or enclosure, such as beams or joists.
Such penetrations shall be protected in accordance with Section 714. There shall not be penetrations or communication
openings, whether protected or not, between adjacent interior exit stairways and ramps.
Exception: Membrane penetrations shall be permitted on the outside of the interior exit stairway and ramp. Such
penetrations shall be protected in accordance with Section 714.4.2.