Do I need to firestop everything? Maybe you don’t…

I talk firestop and all the things you should firestop.

I don’t talk much about things you don’t need to firestop, so I want to share a few thoughts on something that came up on a project recently.

Imagine the electrical room walls have received drywall and the electric panels are mounted to the wall before the opposite side of the wall is closed in.

When this happens it’s easy to say … Hey we have to firestop that hole in the wall.

But do we?

The code is silent on this. There are no firestop detail for toggle bolts in fire rated walls. If we talk to the firestop companies, they are going to have firestop blinders on and they are going to say YUP, go ahead and firestop it.

Now I’m not going to say that firestopping that is a bad idea. Especially if you have a smoke barrier that will require an L rating on the firestop applications. I will get to that later, but for now let’s look at my argument for why we do NOT need to firestop these toggle bolts. (see the bottom of this post for that code section 713.5)

Here is the list I will go over this week:

• Membrane vs through
• Altitude vs pressure
• What’s on the other side?
• Good, Better, Best

So, see you tomorrow for more. For now, here is the code section referenced earlier.

713.5 Penetrations in Smoke Barriers

Penetrations in smoke barriers shall be tested in accordance with the requirements of UL 1479 for air leakage. The air leakage rate of the penetration assemblies measured at 0.30 inch (7.47 Pa) of water in both the ambient temperature and elevated temperature tests, shall not exceed: 

1. 5.0 cfm per square foot (0.025m3 / s × m2) of penetration opening for each through-penetration firestop system; or 
2. A total cumulative leakage of 50 cfm (0.024m3/s) for any 100 square feet (9.3 m2) of wall area, or floor area.

**Code sections pulled from the 2009 IBC. I’m expecting this to be the same in the future code cycles but please check to confirm.