Fire Stop Cable Penetration

[thanley]

I'm preparing to run structured media wiring throughout my house that was built in 1990. Crawl space and attic that are both easily acccessable and I've spent time recently running line voltage Romex for additional and modified circuits so I know the layout well.

With the way the house is layed our putting the structured media box right next to the circuit panel is going to be the most central location as this is all in the garage.

What I am trying to wrap my mind around is fire barriers with wires and conduit that goes through the top plate from the garage all the way to the attic. I will finish drywalling the garage as soon as I get this wiring done. (All wiring is on the "outside" wall which until now has not been drywalled or have any other fire barrier.

So...the question(s):
whats the best practical way to provide a fire barrier for the original electrical wiring that just has bored holes running through the top plate.

I plan on using electrical PVC conduit for the low voltage stuff to help future proof. I need to run the conduit from the garage through the exterior walls and up to the attic. When it comes to firestopping what is the best way? My initial thought is one of the Metacaulk firestop collars for the exterior of the conduit on both the insertion point in the garage and the exit point in the attic.

Am I overthinking? Not considering something? The conduit will run all the way to the media box in the garage but I had initially planned on just having it be "open" at the top.

thanks in advance.

 

[pattenp]

There is a spray foam in a can just for this purpose.

 

[thanley]

agreed; just wasn't sure if there was anything else I needed to consider!

this might have been just me overthinking it all and the spray foam is the ticket.

Thanks

 

[jeffmoss26]

They also make firestop caulk and putty.

 

[rlitman]

BTW, I believe that the regular "Great Stuff" foam is rated the same as a "fire stop" as that pictured can.

It is easy to use, but if you know the stuff, you'll know how it gets everywhere, and sticks to your skin for weeks. Also, if you're going to be running more wires in the future, it is difficult to cut out, around existing wires.

If you have conduit runs, I would use great stuff to seal around the perimeter of the conduit, an the red firestop caulk to seal the ends. That is easier to remove when you want to make changes.

 

[Steevo]

We use EZ-Path products for our facilities:

http://cableorganizer.com/sti/ez-path-cableway-systems/

You do not want to be in a situation where your insurance company can say you compromised a firewall and deny your claim.

 

[jeffmoss26]

Steve, I have a few samples of their single cable firestop grommets. They look nice. I know that brand as one of the 'industry standards' in firestopping.

 

[theoldwizard1]

Plenum rate low voltage cable will not sustain a flame even when installed vertically.

 

[aandpdan]

If this is something that needs to be inspected, check with your AHJ. My building inspector is adamant that the "red fire proofing" including "Great Stuff" will not pass inspection.

In my case I have to use black "fire brick mortar." It comes in a tube just like caulking.

 

[jeffmoss26]

Yes, you are supposed to use riser cable for vertical runs between floors.

 

[6768rogues]

I used to inspect firestopping systems in large commercial projects.
There are two types of firestopping material, intumescent and endothermic. Intumescent swells up under heat. Endothermic gives up moisture and retards the spread of fire, but does not swell up.
Plastic conduit will burn away and leave a hole. It should be firestopped with intumescent material. Metal conduit will not burn away for quite a while and can be firestopped with endothermic material.
Fire caulks, putties, foams, pillows, etc. do not have fire ratings on their own. They are components of tested systems. Each has limitations in its use. For example, a fire caulk might be acceptable for metal piping through gypsum wallboard with an annual space of 0 to 1/2 inch. That means it can be used for metal pipe through GWB with a space around the pipe of 0 (touching the wallboard) up to 1/2 inch. It would require filling the gap to the full depth of the GWB and putting a surface bead where the pipe touches the GWB.
If you want to do it correctly, you need to get a book of tested systems from the supplier of the firestopping material. For example, Hilti has a firestopping manual that shows the type of construction, the penetrating item, and describes a tested system and product for that installation.
Simply buying a UL approved product and using it is not the right way to do it. My toaster is UL approved, but I cannot firestop a hole in the wall with it.
If you have a sleeve where wires will be changed or added, you can use a tested system to firestop the sleeve and then use a firestop putty in a tested system for inside the sleeve. Then you can remove the putty, add a wire, and put the putty back.
Ask a Hilti rep, or a 3M rep, or a rep from any company that markets firestopping products and they will know what I am talking about. Making up your own system is better than not doing anything with the hole, but not much better.

 

[MrMark]

Is there any requirement for firestopping of wiring penetrations through the top plate in residential construction? I have never seen it and would be very hesitant to spray that awful foam on my wires unless I had to.

Anyone know the rules?

 

[aandpdan]

Is there any requirement for firestopping of wiring penetrations through the top plate in residential construction? I have never seen it and would be very hesitant to spray that awful foam on my wires unless I had to.

Anyone know the rules?

When I gutted my house and rewired, the building inspector required that all top plate and bottom plate penetrations be sealed. Between studs no.

It was inspected as part of the framing inspection.

 

[ishiboo]

When I gutted my house and rewired, the building inspector required that all top plate and bottom plate penetrations be sealed. Between studs no.

It was inspected as part of the framing inspection.

Same here. All my wires get foamed, inspected or not. If it's in a room with a subwoofer, they get foamed in the studs too

 

[ishiboo]

BTW, I believe that the regular "Great Stuff" foam is rated the same as a "fire stop" as that pictured can.

It is easy to use, but if you know the stuff, you'll know how it gets everywhere, and sticks to your skin for weeks. Also, if you're going to be running more wires in the future, it is difficult to cut out, around existing wires.

If you have conduit runs, I would use great stuff to seal around the perimeter of the conduit, an the red firestop caulk to seal the ends. That is easier to remove when you want to make changes.

Yes, the orange foams are the same as the equivalent yellow foam.

The can posted was for the Great Stuff gun, they ONLY make the orange (closed cell) and the regular open cell (windows and doors), and they price it the same. The orange cans which are 4X normal price are a huge ripoff.

 

[MrMark]

I wonder if it is an insulation thing. Where I live insulation is not such a big deal and the older houses didn't even have it. I certainly don't sweat insulation when the ave coldest month is like 8 degrees different from the ave hottest month.

I just can't remember ever seeing the foam stuff shot on wires around here.

 

[aandpdan]

I wonder if it is an insulation thing. Where I live insulation is not such a big deal and the older houses didn't even have it. I certainly don't sweat insulation when the ave coldest month is like 8 degrees different from the ave hottest month.

I just can't remember ever seeing the foam stuff shot on wires around here.

Not from my conversation with my inspector. He explained how fire travels through a structure and spreads. Those little holes around the wires allow heated air and gases to travel up the wall, like a chimney, and into the next floor. Holes around pipes are a bigger problem.

It's all to slow the spread of fire and buy you time. That's all it does, it won't stop a fire.

 

[MrMark]

Thank you. I am going to look at some new construction to see if I have just been missing this. I have asked about it before locally and been told you don't need it, but . . .

 

[6768rogues]

Probably an insulation thing. Firestopping is generally required between stories of a building and the attic is not a story. However, properly firestopping the penetrations will meet the energy requirements and will add a level of safety. When a fire reaches the attic, it spreads across the structure quickly.

 

[Motofixxer]

Top plates should always be sealed for drafts as a minimum. It's best to contact your local inspector and ask. I used spray foam that was approved by one inspector only to be told it wasn't accepted by the next. So its best to find out from the actual one who will inspect.