In-cavity Cat6 Cabling

gaelicyoda

Hi all,

I've read varying posts on this site about using the wall cavity as a means of running wiring from one floor to another, and there seems to be those who think it's fine to do, and those who disagree and think that potentially bridging the inner and outer leaves of a cavity wall is just a bad idea.

Most of these posts have generally been about running power cables, but I am shortly going to begin retrofiltting my own house with Cat6 calbling. So, my plan is this:

1. Drill a 30mm hole at a downward angle through the inner leaf of the gable in the attic
2. Use cabling rods (such as these for example) to push down to the ground floor (~5-6m).
3. Use an electrical box cutter bit (such as this) to cleanly cut out the RJ45 socket(s) on the ground floor.
4. Drill through the back of that again, and at an upward angle, to gain access to the cavity. Again, 30mm hole)
5. Line up the rod to the hole (this I suspect will be the hard/time consuming part, but with rigid poles to control movement, and movent only possible in left/right direction, I expect I will get it eventually - probably a two man job though)
6. Attach a 25mm conduit containing the cables to the rod end and pull back up to the attic.
7. Finish by using expanding foam to seal the gap between the conduit and the blockwork at both ends.

The end result should hopefully be something like this:



(Note: the purpose of the angled drilling is to minimise the bending of the Cat6 cable. a 90 degree bend could damage it)

I don't expect this to be plain sailing though. The main stumbling blocks will be steps (2) and (6). As you can see above, the insulation is bonded bead insulation, so the end of the conduit would need to be covered with duct tape or something like that to stop the conduit filling with insulation on the way back up.

Am I dreaming here, or is this achieveable? Maybe ignorance is bliss here, but I think it stands a reasonable chance of success.

Any and all thoughts welcome!

DublinDilbert

The lid of mini trunking is great for fishing cable up or down.

I would imagine youd need to drill a very big hole at the ground floor to fish/rods the cable out of the cavity.

I wouldnt be tempted to use the cavity, seems like hard work. I would probably use internal partition walls and/or existing cable runs...

gaelicyoda

DublinDilbert wrote: »

The lid of mini trunking is great for fishing cable up or down.

I would imagine youd need to drill a very big hole at the ground floor to fish/rods the cable out of the cavity.

I wouldnt be tempted to use the cavity, seems like hard work. I would probably use internal partition walls and/or existing cable runs...

Thanks for the feedback Dilbert - d'oh - I just realised that I didn't mention in my original post that my whole motivation for going via the cavity is to minimize or (ideally) completely eliminate the need for tearing up the walls (except for the sockets of course). I've found that even if you patch up a wall, you can still see the difference in texture when light shines on it, so I want to just try and avoid that altogether.

paddy147

yes,you are dreaming and you will end up having so much trouble that it will just end up in a mess.

Use the void of the battons and plasterboard on the inside of the cavity wall/house.Much easier and less to go wrong.

I speak from experience here btw.

Simples.

slimjimmc

That's assuming the inner leaf is slabbed Paddy147, it could be plastered but if it is battened and slabbed that's the way to go allright.

gaelicyoda

slimjimmc wrote: »

That's assuming the inner leaf is slabbed Paddy147, it could be plastered but if it is battened and slabbed that's the way to go allright.

Thanks for the feedback lads - well, it's basically just exposed blocks at the moment, so no battens or slabbing up on the wall as of yet.

Paddy147, it sounds like you have experience in trying something like this yourself (or perhaps elements of it at least) once upon a time - I'd be very interested in hearing what went wrong for you

LLU

paddy147 wrote: »

yes,you are dreaming and you will end up having so much trouble that it will just end up in a mess.

Use the void of the battons and plasterboard on the inside of the cavity wall/house.Much easier and less to go wrong.

I speak from experience here btw.

Simples.

just wondering: from your previous experience did you cause much disruption to the insulation in the cavity? I'm half considering doing something similar but my main concern is that my insulation is polystyrene beads in the cavity and I fear that these could get knocked out so not sure if it's worth the risk.

paddy147

LLU wrote: »

just wondering: from your previous experience did you cause much disruption to the insulation in the cavity? I'm half considering doing something similar but my main concern is that my insulation is polystyrene beads in the cavity and I fear that these could get knocked out so not sure if it's worth the risk.

I dont do things with cavity walls.Messing with structural walls and inner insulation is asking for trouble.

Also trying to run a 25mm conduit with cables in it down the cavity is not going to happen in my honest opinion......more chance of winning the lottery thnt getting this to work and not causing a total fcuk up of things.

If you have your internal house laid out in 2 x 1 battons and plasterboard off the cavity wall, then simply fish the cables down behind the plasterboard.Still a bit of hassle buy alot less hassle than going near a cavity wall and bead insulation.