T-Rating on Wall Penetration

[msmrphy]

2006 IBC, Section 712 - Penetrations.

Please confirm my thinking here is correct -

Background:

This is for an EXISTING building, single story, unsprinklered Type IIIB building currently housing F2 and B occupancies.

I am re-purposing the building to house S1/B/F1 occupancies. Per AHJ amended requirements, this increase in occupancy hazard causes a need for this building to comply with current code (IBC 2006 with City of Houston amendments).

The total GSF floor area is 14,400 GSF, so I must sprinkler or compartmentalize the fire areas. I chose to compartmentalize, since the area of town is older, and I'm not sure that pressure exists to install a new sprinkler system, even if the owner could afford it.

I have designed a 3 -hr. steel stud and gypsum board fire barrier wall (UL U419) to split the fire area into (1) 10,900 SF area and (1) 3,400 SF area.

My question:

Is about FIRESTOPS.

My question concerns the lack of a T-rating in thru-wall penetrations and joints that surround the 3 hour wall. I have two types of penetrants: 1/2" conduit with 12 AWG copper conductors and 1" dia steel pipe carrying gas supply for radiant heaters.

This section is broken down into two conditions: 712.3 FIRE RESISTANT RATED WALLS and 712.4 HORIZONTAL ASSEMBLIES

And after digging through all that, it seems that NO t-rating is required on thru-penetration firestops for walls. Floors, yes, but not walls. Is there any condition that could require a t-rating on a wall penetration firestopping system?

Does one exist in the 2012 code?

Thanks in advance.

 

[RLGA]

T-ratings are not required for walls.

Since heat rises, the potential for the temperature to cause ignition on the other side occurs where the heat is trapped at the ceiling plane of a floor/ceiling or roof/ceiling assembly.

 

[msmrphy]

Great thanks. I just realized that I'm seeing T-ratings on wall assemblies because they are both wall and horizontal assemblies in the UL catalogs. As you say, you'd need a t-rating for the horizontal aspect of the thru-penetration.

Thanks again. This site is a wealth of knowledge.