Altitude vs Pressure

Let’s think about what happens in fire. Let’s imagine for one horrible moment that there is a fire in the building. If the fire is in the room beside this electrical room, the heat and pressure will go all the way to the ceiling. As the pressure grows and the heat builds, the positive pressure plane will work down the room.

This means the higher the ceiling, the more time until the fire is at the location of the toggle bolts that we are talking about. If the heat and the pressure never reach the highest toggle bolt, then the fact that it is even there is irrelevant.

But let’s say the ceiling is 8 feet height and the highest toggle bolt hole is 6 feet high. Will that toggle bolt allow more heat or smoke through than the electrical outlet if it were at the same elevation? If the code is okay with electrical outlets, it seems it would be okay with the toggle bolt because remember we are talking about a membrane penetration. If this were a through penetration, we would be having very different discussion.

Don’t read this and take it to mean that you can partially firestop a through penetration, or any firestop penetration for that matter. The code allows these breaches and that means that when firestop is required, it is making up for things just like this.

So, see you tomorrow for more where we are going to cover something super important. We will talk about why you need to consider what is on the other side of the wall we are talking about. But that is for tomorrow. See you then!