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Firestops across studs - where are they used? How do you deal with them?

Firestops across studs - where are they used? How do you deal with them?

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  #1  
Old 06-21-17, 08:25 AM
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Firestops across studs - where are they used? How do you deal with them?

I feel like a moron - I was trying to run a data cable in our house from the attic to a 2nd floor room. could have sworn I got in the right cavity to drop the data cable. But couldn't see it at the hole we cut in the wall for the data box.

After my son who never pulled cables suggested, I realized there might be a fire stop in there. Stuck a mirror in there and looked up. Sure enough, there it was.

How do you deal with those when running a new cable other than make a hole above and below it?

Is there a rule of thumb when they are used?
 
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Old 06-21-17, 09:05 AM
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You need to use a long flexible auger bit (they make them in various lengths) and once you have drilled through the top plate and fire blocking you tie your fish tape to the end of the auger bit and drop it down the wall to your other hole. You can then pull your auger and fish tape out that lower hole. Then you can tie a pull wire onto the fish tape and pull it all back up.

There is an art to making sure you tie it so that it doesnt pull apart and also doesnt catch on the edges of the hole as you pull it back up. Think about that as you tie and wrap the connection with electrical tape before pulling it up.
 
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Old 06-21-17, 09:24 AM
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You can get a long flexible drill bit in the electrical tools area of your local home center which will get you through the fire stop. However, fishing through two holes (top plate & fire stop) gets pretty tricky. Another tool that helps in this situation is fish sticks also in the same aisle. These are fiberglass rods with hooks on the end.

It will also help to drill the hole through the top plate oversized, like with a hole saw so you can sight down through the hole and thread your fish stick through the fire stop hole.

...or if you don't want to mess with all that, cut a piece of wall board out and get out your drywall knives.
 
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Old 06-21-17, 09:42 AM
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Wire fishin'

I'm usually on the alarm / security system page but this is right down my alley. The long auger bit idea is probably the best. The only qualifier is that you should use the bit from the attic and drill straight down. To start, drill a large hole from the attic down. Talking like 1" to 1 1/2" with a speed boar (paddle bit). Now you can look down the hole with a penlight flashlight and see what your hitting. If you can see the fire stop, then use the long bit and drill straight down through the fire stop. Your bit should have a hole in the shaft and the end of the auger bit. Pull the bit back up - tie a piece of string on the drill chuck end of the bit - slide it down the hole and through the hole in the fire stop - secure the auger end in the attic so you don't loose your bit (vice grips) - use a piece of coat hanger with a hook in the end to snag the string from your hole on the second floor - tie your new wire to the string and pull it up to the attic. If you drill exactly below the hole in the attic - you can also use a string with a small piece of chain on it but they need to be lined up almost exactly.
Good luck fishin.
 
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Old 06-21-17, 09:48 AM
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thanks guys! Yeah, older - that big hole at the top helps me alleviate my fear of drilling through / nicking wires that are in the area. But I guess the bit's not spinning till it gets to the firestop. But I'll find a way : (
 
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Old 06-21-17, 09:31 PM
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But I guess the bit's not spinning till it gets to the firestop.
Not quite following you there. The bit should spin when the drill starts.

If you mean don't spin the bit until it hits the firestop.... that is correct.
You don't want that long bit bouncing around in the wall.
 
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Old 06-22-17, 08:42 AM
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SOrry - dumb humor. you'd drill through the top header. then stop the drill to lower it down to the fire stop / avoid wires that might be in there, then start the drill bit again once it's on the firestop, rather than spinning / nicking cables that might be in the space as the bit lowers.
 
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Old 06-29-17, 08:54 AM
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reason for horizontal fireblocks inside wall

The question that wasn't answered in this thread is when/where/why is horizontal blocking used in the first place. I realize that it's motivation could be: fire blocking, strengthening wall, surface on which to attach horizontal seams of wall siding. However, the question I have is whether each of these reasons are motivated more by best practice and are therefore optional, or are any of them actually mandated by code (which code?). The state of interest is Maine.
 
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Old 06-29-17, 10:07 AM
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It most likely isn't fire stops just Cleats for hanging kitchen cabinets or something like that what year was your house built roughly
 
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Old 06-29-17, 11:20 AM
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Supposedly built in 1990. There are two levels of blocking within the wall, splitting it up roughly into thirds. The level of each block is not exactly the same going across from one stud cavity to the next - just roughly the same. I am not sure if the two habitual stories above ground are done the same way. I have observed this in an interior, non load bearing wall in the basement. However, this is commonly found in many homes in this part of the country. In videos, tutorials, and discussion boards, it is often referred to as "fire blocking." But I am just not sure what the real reason is, and whether, as I say, it is optional or mandated. These walls are interior walls with sheet rock on both sides.
 
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Old 06-29-17, 06:40 PM
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They did it to "attempt" to keep the 2x3's from bowing. They were probably all over the place.
 
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Old 06-30-17, 10:59 AM
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In some local/state codes horizontal fire blocking is required in stud spaces. It is not required in the national / model codes for standard residential new construction. You'll also run into it in much older houses like 19th century up to maybe 1950 which were balloon framed that have all sorts of horizontal blocks and bracing in random places.
 
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