Pass Through Couplers

[kwschumm]

For a new build I need to run network and surveillance cables up a low voltage wiring shaft into the attic and then out to the destination.
 
Of course the wiring shaft needs to be sealed at the top for fire code.
 
I was thinking that sealing the shaft with plywood and installing pass through couplers through the plywood would be a great way to do this. Never did like rework-ability of spray foam. This is my house so the incremental higher cost won't be an issue.
 
I'm a little concerned about losing some signal integrity through the use of them though.
 
Anyone ever done this before?

 

[wuench]

Most  data centers I have seen use solid foam that expands in a fire to block the chases...  This is the closest I could find.
 
https://www.cableorganizer.com/fire-protection/fire-stop-devices.html

 

[pete_c]

My electrical conduit going to the attic used expando foam and when I ran network cabling from the basement to the attic in the two story and used expando foam too.  All the CCTV under the second floor eaves came from the attic.  I built a chase from the basement to the attic.
 
I did once have an issue with the 120VAC smokes on the second floor due to moisture dripping down from the attic to the metal cans used for the smokes. 

 

[drvnbysound]

I've been in some commercial spaces where I've seen 4" conduit sealed with a fire putty; apparently named intumescent putty according to the link wuench shared above. Literally, exactly like shown in many photos on that page where the cable simply passes though the conduit w/o termination...  like this: 
https://www.cableorganizer.com/sti/ready-sleeve-firestop-kits/

 

[Neurorad]

Duct Seal is another brand of conduit putty, to block the spread of fire (and bugs), in conduit.

 

[tmbrown97]

I've used the jacks you're talking about at times - but never for that application.  In theory you lose a little signal but with just one in the mix, you'd be fine.  However, they are another connection point - they can get dirty over the years and deteriorate the connection quality, especially in a dirty unconditioned space.  Plus, if you have a bad insertion, how far will that wire fall back into the wall?
 
Personally I'd run everything now in a single conduit and seal it up as suggested above - but also leave 2-3 extra tubes coming up that are just capped and not plugged with fire putty - so if you choose to use them in the future, you can run the next bundle up, then seal them as well (lets be honest; homeowners never worry about code once the inspector leaves; they'd just use it as an open conduit for the future).