Fire Stops in walls

[N9JIG]

I am preparing to run several (about a dozen) coax runs from my attic into my office for the radios and trying to figure out how to get the coax runs down the wall. I had planned on drilling a series of holes in the cap to route the wires down but I have run into a snag.

I used a stud finder to see if my interior walls have fire stops and it appears they do, so it will be next to impossible to get them run thru the wall down from the attic.

Is there a way, short of using a drill bit with a 6 foot shank, to do this? The only other way I can see is to open up the wall, which would mean a certain divorce or my death from the wife.

 

[ke4psa]

i hate to say it, but the preferred way is the 6ft "installer bit because after drilling, you can tape your lines to it and pull everything thru.

that said, using a utility knife and cutting at 45degrees to the flat wall, you can cut out segments of wallboard and easily tape/mud them back in without need for backing(think 4"x4" inner hole, but with a 5"x5" bevelled face, the bevel will keep the piece from falling back into the wall when you cover up your holes!!

and if your wires will penetrate the wall, i would recommend a flush mount and junction box, the cleaner the look, the less odd looks you'll get from the Mrs or any wandering eye of an electrical inspector!!

you can always do it right the 2nd time, but fines make it more expensive!!

 

[Thayne]

It can be a pain, but they make 12"-24" extensions you can use with paddle bits once you get thru the cap. Be careful and tighten the setscrews on the extension(s) so you don't lose the whole deal, and look thru the cap holes with a LED flashlight to see any other problems such as other cables, etc. Small window sash chain works great for dropping down as a fish chain. Also sometimes you can get a lot of cables down the same bay as a plumbing vent if it is near where you want to end up.

 

[iMONITOR]

I strung CAT5e network cables through my heat vents, and cold air returns.

 

[jland138]

We use several runs of 2" Schedule 40 PVC conduit in an adjacent closet, down from the closet ceiling and terminated on closet side wall with an LB conduit body. On the other side of the wall, we cut in a standard PVC electrical wall box with the back removed. Cover the electrical wall box with bulk cable wall plate (see: Quest Technology Dual Gang Polished Bulk Cable Wall Plate White VHT-8201 - Micro Center). If you decide you no longer need it, you can swap this with a blank plate. Nobody cares about conduit in a closet.

 

[n9mxq]

How far from the radios is the main wet wall?

 

[SCPD]

Out and in

Is there any practicality to coming outside the building, around the firewall, and back in?

 

[AK9R]

Rich, are you finding these "fire stops" in the wall within one floor of the house? In other words, is the blockage in the middle of the first or second floor?

The point I'm getting at is that in most new house construction, you don't generally find fire stops in the middle of a floor. New houses are built by building a floor deck with sub-flooring applied (or pouring a concrete floor for a slab house), then building the walls on that deck, then building the deck for next floor up, then building the walls for the second floor, finished by resting up the roof trusses on the stud walls. The sub-flooring and the sill and top plates of the walls become the fire stops. And, under most building codes, the builder comes back after the plumbing, electrical, and HVAC is installed to squirt fire stop material into the penetrations between floors. That's sufficient under most building codes to "fire proof" the house. A fire in one room of a house is bad enough, but the codes are designed to stop that fire from spreading to other parts of the house.

What's more likely that horizontal blocking was put into the walls to strengthen the wall or provide attachment points for stuff inside the house (cabinets, bathroom fixtures, etc.). The corners of the house are a common place to find horizontal blocking. Also, if an interior wall meets an exterior wall in the middle of a stud bay, you'll find horizontal blocking in the exterior wall so the framers will have something to attach the interior wall to.

A hundred years ago, multi-story houses were built using what they called "balloon framing". Long studs ran the full height of the house and the floors were attached to the inside of the stud walls. Those houses were often not built with any fire stops, so a fire in the first floor could travel right up the stud bays to the second floor. The so-called "western framing" that we use these days where the studs only run the height of one floor and the floor decks are resting on the stud walls is pretty much the only way that wood framed houses are built today.

If it were me, I'd check the stud bays to the right or left of where you are finding the blocking to see if there's also blocking in the adjacent stud bays. Of course, if you do find blocking, my theories get blown out of the water.

As for getting through the blocking, a long drill bit is the way to go. You should be able to find long bit extensions at your local home improvement store.

This won't help you now, but when my house was being built, I spent an afternoon in the house the day before the insulators came in taking photographs of every wall in the house. Even though the walls are now sealed, I can go back to my photos to see where blocking, plumbing, electrical, and HVAC ducts are located.

 

[radioman2001]

Fire stops mid wall are now becoming common practice in residential buildings especially in cities, and it doesn't cost that much more to do when the wall is open.. While it is a PIA I wouldn't breech one. The proper way to do it is cut the sheet rock above and below the stop remove it then cut the stop as much as you need to run your cabling and then use fire retardant silicone and reseal the hole then re-sheet rock and spackle. It's some times easier to make a large hole and then use the piece to reseal it.
I have investigated many a fire that was stopped by the fire stop and the building was saved along with the residents.

 

[N9JIG]

It is a single story home, 6 years old on a pre-stressed slab in the desert. There are 10 foot ceilings, and the fire stop where I want to run the dozen or so coax lines is about midway up the wall. On the other side of the wall is the laundry room with cabinets.

I wonder if it might work better to run the coax down the outside of the wall on the laundry room side of the wall then thru the wall into the office.This might allow me to avoid having to breach the cap or fire stop.

There is another alternative I thought of before where I would run the coaxes from the attic into the garage (which abuts the other wall of the office) and then into the house from there. I could then drill a 2 or 3 inch hole from the garage into the office, put in a short length of pipe thru the wall and seal it off with flame-retardant sealant.

The third alternative would be to run the coax down the corner of the wall inside the office and build a chase around it, painted to match the room.

Regardless of the method I think a carpenter is going to be needed...

 

[QDP2012]

...There is another alternative I thought of before where I would run the coaxes from the attic into the garage (which abuts the other wall of the office) and then into the house from there. I could then drill a 2 or 3 inch hole from the garage into the office, put in a short length of pipe thru the wall and seal it off with flame-retardant sealant....

You've probably already considered this, but in many modern houses, there is extra protection requred between the garage and the rest of the structure, so that carbon monoxide from vehicles/mowers/etc. in the garage cannot poison the people in the house. You might want to choose one of the other options you mentioned, and not breach the garage wall.

Hope this helps,

 

[n5ims]

These (B.E.S. 1/2" x 72" High Speed Steel Flex Bit : FLX1272) actually work quite well and come in various sizes. The shaft is quite flexible (I've seen it bend 180 degrees so the drill doesn't have to be in direct line with the hole) so you can simply cut an outlet box size hole (for a nice clean looking mounting, using an existing construction outlet box and faceplate) and drill up through the fire stop. There's even a hole in the bit for pulling the wire back down.

 

[mmckenna]

Or just get some large Panduit duct. This is commonly used for telephone/data cabling in buildings where its not possible to go down the inside of the wall. Have it come down behind your radio desk and stop there. Cabling can come out the end and to your radios.
http://www.panduit.com/ccurl/88/673/wiring-duct-selection-guide-wdsg01.pdf

 

[jim202]

Rich, are you finding these "fire stops" in the wall within one floor of the house? In other words, is the blockage in the middle of the first or second floor?

The point I'm getting at is that in most new house construction, you don't generally find fire stops in the middle of a floor. New houses are built by building a floor deck with sub-flooring applied (or pouring a concrete floor for a slab house), then building the walls on that deck, then building the deck for next floor up, then building the walls for the second floor, finished by resting up the roof trusses on the stud walls. The sub-flooring and the sill and top plates of the walls become the fire stops. And, under most building codes, the builder comes back after the plumbing, electrical, and HVAC is installed to squirt fire stop material into the penetrations between floors. That's sufficient under most building codes to "fire proof" the house. A fire in one room of a house is bad enough, but the codes are designed to stop that fire from spreading to other parts of the house.

What's more likely that horizontal blocking was put into the walls to strengthen the wall or provide attachment points for stuff inside the house (cabinets, bathroom fixtures, etc.). The corners of the house are a common place to find horizontal blocking. Also, if an interior wall meets an exterior wall in the middle of a stud bay, you'll find horizontal blocking in the exterior wall so the framers will have something to attach the interior wall to.

A hundred years ago, multi-story houses were built using what they called "balloon framing". Long studs ran the full height of the house and the floors were attached to the inside of the stud walls. Those houses were often not built with any fire stops, so a fire in the first floor could travel right up the stud bays to the second floor. The so-called "western framing" that we use these days where the studs only run the height of one floor and the floor decks are resting on the stud walls is pretty much the only way that wood framed houses are built today.

If it were me, I'd check the stud bays to the right or left of where you are finding the blocking to see if there's also blocking in the adjacent stud bays. Of course, if you do find blocking, my theories get blown out of the water.

As for getting through the blocking, a long drill bit is the way to go. You should be able to find long bit extensions at your local home improvement store.

This won't help you now, but when my house was being built, I spent an afternoon in the house the day before the insulators came in taking photographs of every wall in the house. Even though the walls are now sealed, I can go back to my photos to see where blocking, plumbing, electrical, and HVAC ducts are located.

Fire codes have changed over the years and most jurisdictions have adopted the new codes that require the fire stop to be put mid way in most vertical walls. So expect a problem if the structure was built after some time in the early 2000's or so.

 

[N9JIG]

You've probably already considered this, but in many modern houses, there is extra protection requred between the garage and the rest of the structure, so that carbon monoxide from vehicles/mowers/etc. in the garage cannot poison the people in the house. You might want to choose one of the other options you mentioned, and not breach the garage wall.

Hope this helps,

If I sealed the breach with weather and fire resistant sealant (that gooey expanding foam stuff) after running the cables thru it do you think that would suffice?

I just have so many coax runs I want to put in, I would have to drill several holes in the fire stop to fit them in so that would reduce the effectiveness of them.

 

[N9JIG]

Or just get some large Panduit duct. This is commonly used for telephone/data cabling in buildings where its not possible to go down the inside of the wall. Have it come down behind your radio desk and stop there. Cabling can come out the end and to your radios.
http://www.panduit.com/ccurl/88/673/wiring-duct-selection-guide-wdsg01.pdf

That might be difficult to get past the wife but I might try to see if there would be a way to camouflage or hide it. With 10 foot ceilings there would be a good 6 feet of this exposed. I suppose this might work in the other corner, where we have a 6 foot wall unit in place.

 

[AK9R]

If I sealed the breach with weather and fire resistant sealant (that gooey expanding foam stuff) after running the cables thru it do you think that would suffice?

I just searched on HomeDepot.com using the term "firestop". It gave me a couple of hits for the expanding foam fire-stopping material. I would imagine Lowes has it, too. I will assume that the expanding spray foam weather-stopping material may not have the fire resistant rating that the fire-stopping material has. When my house was built in 2008, the last thing the electricians and plumbers did before the insulation batting was installed was spray the firestop foam in all of the penetrations in the top and bottom sills. The electricians also sprayed it in the penetrations in the electrical boxes.

 

[N9JIG]

But if I used it to seal a breach between the garage and den it should be OK? This would be a 2 or 3 inch hole they the common wall, not the 2x4 fire stops.


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[jeatock]

Rich:

Take your wife out to a nice dinner (or whatever works) and when she's in a good mood explain that you need to open up the wall ONE TIME and put in a pair of the biggest diameter plastic pipes that will fit. Explain that after the wall is repaired it will be better than new and you will never have to have 'just one more' run of coax visible.

It may cost you a week of planting petunias but will be worth it in the long run.

 

[mmckenna]

That might be difficult to get past the wife but I might try to see if there would be a way to camouflage or hide it. With 10 foot ceilings there would be a good 6 feet of this exposed. I suppose this might work in the other corner, where we have a 6 foot wall unit in place.

Placing it in a corner and painting to match existing works pretty well. Not the ideal choice, but might be easier than opening up the walls.
We've used it in a lot of places at work where there were concrete walls and there is no other option. Looks better than bare EMT conduit.
There is some pretty big versions of this stuff, so wouldn't be an issue for a number of coax runs. There are even divided versions so you can run different services inside. Coax down one side, 220v down the other for your amplifier.