# Cable in commercial TI with rock to ceiling



## Awg-Dawg (Jan 23, 2007)

Going_Commando said:


> I wanted some ideas on how to a) hang the cable (I was going to use bridle rings), but what should do I do through the interior partitions? PVC pipe sleeve?.


 I’m not sure what you mean on how to hang the cable?

But thru the wall, I do what you’re saying , except I use EMT with knock on bushings.


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## macmikeman (Jan 23, 2007)

Going_Commando said:


> Hey guys, the job I'm working on now has sheetrock running up in the interior partitions up to the sheetrocked lid above the drop ceiling. This is a new thing for me to deal with, as the brunt of the commercial TI's I have done only have rock going up a bit above the grid, so I wanted some ideas on how to a) hang the cable (I was going to use bridle rings), but what should do I do through the interior partitions? PVC pipe sleeve? I just don't want the rockers to smash the cables up against the steel top plate.


Use your tin snips. Cut out a channel in the top plate for the cables, use a two hole strap exactly centered in the channel you cut to secure the cables at that spot and keep going. The rocker will notch around your cables. You could even strap a short pipe up in that knocked out top plate also that way for a chase if you have that bad of rockers.


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## 99cents (Aug 20, 2012)

Even the brainless drywallers I deal with have enough sense to cut a notch. I would cut out a piece with tin snips like mac says or drill a hole with a step bit.


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## splatz (May 23, 2015)

I am assuming this is NM and you made sure the ceiling rating isn't an issue. I'd prefer to just make a full stub, from the box to the 90 into the ceiling space. One piece of conduit per box, one bend, and it doesn't have to be exact. Two hangers into the stud and you're done. It might not come out more than a couple bucks a box different. 

Bridle rings are OK but it might come out nicer to just tack up strapping on top of the drywall and staple to that. Not a big deal if there's lots of vertical space between the drop ceiling and the drywall ceiling but I doubt that's the case.


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## 99cents (Aug 20, 2012)

NM in a commercial TI with steel studs?


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## splatz (May 23, 2015)

99cents said:


> NM in a commercial TI with steel studs?



I was assuming if it's MC you wouldn't even worry about it, like you say they'll notch around it and even careless drywallers won't harm the cable. (BTW I'd also strap it so it exits the wall a couple inches below the top plate, forcing them to notch around it, removing the temptation to slam the cables between the top plate and edge of the sheet.) 



When I hear a drywall ceiling above the drop ceiling, I think of a building being repurposed for office use, an old store or old house or etc., and around here if the building type and ceiling rating allows NM, it gets done in NM.


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## Going_Commando (Oct 1, 2011)

This is for Cat6, security and fire cable, hence why it's in the structured cabling sub forum. The MC I don't care about. I have already been notching top plates like gangbusters for pipe, so I will keep rolling with that. I like the 2 hole strap idea too.


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## MTW (Aug 28, 2013)

I like the idea of PVC or EMT sleeve for every partition. Yeah, more labor but definitely protected from any kind of damage.


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## splatz (May 23, 2015)

Going_Commando said:


> This is for Cat6, security and fire cable, hence why it's in the structured cabling sub forum. The MC I don't care about. I have already been notching top plates like gangbusters for pipe, so I will keep rolling with that. I like the 2 hole strap idea too.


Definitely just stub up from the box to the ceiling space. I'd use low voltage mounting rings with the open back and KOs for the conduit. 



Use these, Arlington LVMB1 or LVMB2 for 2-gang












and / or the LVMB1 












If you place your boxes back to back in the same stud bay, you can serve two boxes with one conduit. You can leave all your slack in the wall. FAST


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## joebanana (Dec 21, 2010)

"Drywall all the way to the ceiling"? Sounds like a fire rating. Use EMT sleeves, and bang-on bushings, so you can firestop it. Caddy "J" hooks might be more direct than bridal rings.


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## Cow (Jan 16, 2008)

We'd probably precut a bunch of emt nipples with pound on bushings in the shop.


Then have a guy run around and notch the top plates out and strap the nippled in where needed. It'd be a good job for an apprentice or helper if you have one.


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## VELOCI3 (Aug 15, 2019)

The walls are probably fire rated. If it’s a plenum up there no PVC sleeves. 


Sent from my iPhone using Tapatalk


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## macmikeman (Jan 23, 2007)

I'd wait till the sheetrock was in then poke holes in that, run the cables and fill the space around the cables with expanding fire stop foam from Home Depot. 
They got's flame resistant cables out there for this. And calc's for how much penetrations of the firewall can be made in square inches.


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## Lightsmith (Oct 8, 2010)

I would want a security and fire cable run done with EMT to protect the cable from mechanical and fire damage. Surprised that this isn't mandatory.


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