Solid Floors
When the floor assembly is monolythic such as with concrete or CLT, hollow core, PT deck, cast in place or any concrete floor assembly including hollow core the penetration of a tub or shower lands in the THROUGH penetration category of the building code.
When the floor assembly is wood framed or a G 500 assembly such as Hambro, Epic deck and others, then the shower/tub drain is a membrane penetration and we have to shift to a different section of the code and that my friends, is where the game changes.
Let’s start with the through penetration section for this discussion. The legacy codes and the I codes had T ratings as requirements until the 2012 IBC when the through penetration section discussing T ratings received a second exception that read and still reads like this
- Floor penetrations by floor drains, tub drains or shower drains contained and located within the concealed space of a horizontal assembly do not require a T rating.
I discussed a code change proposal, suggesting that this section says “horizontal assembly” should be changed to “horizontal fire-resistance rated assembly” because builders were/are simply putting up a hard lid or a grid ceiling to say that this code section was achieved, but it was not a rated assembly and therefor it was not achieved.
My suggestion was summarily shot down because the people I was talking to don’t go in the field. They just look at the code and they understand it on a level that the field crews don’t. These people told me that the way the code is written it is expected that this is a horizontal fire resistance rated assembly because this code section is in chapter 7.
Do you agree? Is this clear to you? (it’s not to me, but maybe I’m just slow…_
How do you read this code section?? If you have a PT deck do you allow a hard lid to eliminate the T rating for tub and shower drains? Does it have an access panel? That is not going to be required to be rated… What do you think is okay or not okay here?
