Not sure how to install fire block? I’m your huckleberry. I know that’s a movie quote from somewhere but I can’t remember where. I think it means I’m your man or something southern macho like that.
If you’re reading about fire blocking then I know you must be either:
1. Someone who plans way ahead (kudos to you!)
2. Someone who is presently freaking out. Perhaps because you missed a major step in your basement finishing project.
Either way, I know I can help you. During my basement finishing project I was the latter. The guy freaking out.
I remember, it was a Monday. I mentioned to my friend Tom that I was done framing my basement walls and had scheduled my framing inspection for Thursday. He goes, “Cool. You are really doing it.” then casually mentions as he walked away. “Don’t forget fire blocking – they’ll fail you for sure.”
WHAT!!! What the hell is fire blocking? Can I do it in 3 days?
The purpose of fire blocking is two fold. Starve a fire of oxygen and prevent it from spreading. Ironically, fire blocking material does not have to be fire-proof. It just has to keep the fire from getting fuel (air/oxygen).
When you’re finishing your basement, you need to install a fire block in the gap between the top plate of your framed wall and block wall of your house foundation.
Believe it or not, that’s the best explanation I was able to write after 30 minutes of my hamster brain running. Read these other sections and it will make more sense. I know, you’re probably thinking “what the hell is he trying to say???”
What material can I use as a fire block?
I recommend using drywall as a fire stopping material. You can also use 2x4s, plywood, rigidly packed insulation, fire foam and sometimes sheet metal. I used drywall for my basement. I was a bit short on time so drywall was easiest to cut to the right width and length. It passed inspection without any issues.
How do I “install” fire block?
Fire blocking isn’t something you’ll see at the Home Depot labeled “fire stopping stuff” or “fire block”. It’s just material (drywall in my case) that’s nailed into the gap between your top plate of your framed walls and the foundation of your house.
So you’re going to cut a strip of drywall (or other material) the width of the gap from the block wall to the framed wall, probably 4 to 5 inches. Then push that strip of drywall up into that space. Take a few nails or screws and secure to the material in there so it doesn’t fall. It doesn’t have to hold Andre the Giant, just its own weight, so a couple of screws or nails should do it.
If you have small enough gap just use some fire foam and it will expand to fill the space. Plus, it fun to squirt.
Fire Block Space around Holes for Pipes or Wires
If you drill a hole in the top plate of a wall so you can run plumbing pipes or wiring you need to stuff some rock wool or insulation in the remaining space.
Yes, even a little tiny space. Don’t shortcut it.
If a fire is burning behind your wall and that space is open the fire will suck air into the gap and go burn crazy.
No hole… the fire should just smolder or even go out. Giving you, your family and your fire department time to react.
Not sure what you can use to fire block? Ask your Inspector!
If you’re not sure about what you can use in your area for fire blocking, ask your inspector. Don’t be afraid to call, they are there to help you! Call them. Here’s what you say. I wrote it down for you.
You: “Hello, I’m finishing the basement of my house and I have a question about fire blocking .”
Inspector Receptionist: “Okay, no problem, hang on while I get _____ (Fred).
Fred: “Hello? What ? (Fred is a little hard of hearing, due to that one air show he went to where he stood right next to the engine while it “warmed up”.)
You: ” Yes, Hello… Fred… What material do you recommend for fire blocking if I’m finishing my basement? Is it okay to use drywall?
Fred: “Yes….yeah… drywall is A-okay! Thanks for checking.”
See. That was easy. He even said thanks for checking, so you know you are good to go.
3 Questions, 3 Answers – About Fire Blocking
Q: Do I install fire blocking before or after wall framing?
A: After. You can also do it as you go along. I didn’t even know about it so for me… after was good.
Q: What if I don’t install fire blocking?
A: You will fail your framing inspection. Well, you “should” fail. Not a huge deal, you don’t get penalized or anything – you just have to install the fire block before they will pass you. In most areas they’ll come back for another inspection at no extra charge.
Q: What is horizontal fire blocking? Do I need to worry about it.
A: So, the fire blocking we’ve been talking about is vertical. It stops fire from moving up. Horizontal fire block stops fire from moving sideways. My county did not require horizontal fire blocking. It wasn’t even mentioned at all in the building codes. Check your code, but it seems like it’s not required in many areas for basement finishing – check your code though.
You’re doing awesome! Keep going with your basement finishing! It’s going to be so worth it.
If my awesome explanation wasn’t good enough, although I can’t see how that would be, feel free to leave a comment or question below this post.
Cheers – Jason
More Firey Links :
- Links about framing your basement.
- Do you enjoy spending too much for power tools? Don’t click here then.
- If you only buy 1 book on framing, here it is.
- How to buy lumber for your basement project.