Cavity wall access from Loft to 2nd floor for low voltage cable.

Beefy · May 10, 2020

Hi guys,

I know this is technially not a mains electrical question as it's regarding network cable (CAT7) rated for inwall installation. But my question follows the same theory. I'm looking at dropping a few network cables from the gable end of my wall in the loft down into a room on the 2nd floor. The wall in question is an externally facing wall. (End of terraced external wall)

In your experiences does the cavity from the loft gable end run into the 2nd floor cavity wall with no obstructions? (Wood, Brick, Mortar seperating the floors?) Does it also run down to the ground floor with no obstructions? Wasnt sure that as the loft was breeze block whether it would not run in parallel with the brick cavity?

My house was made in 1956 and has no in wall insulation. Any advice or experience people can share would be amazing before i core out a 50mm hole

I've included a picture for a bit of context.

Thanks chaps!

davesparks · May 11, 2020

Beefy said:
I here your concern. It's thicker, and less manageable than other categorizations. I'm an IT guy needing 10gb speeds for 10gb enabled servers for home lab work otherwise i totally would have gone for CAT 5e or 6 for it's ease of installation.

In which case you want it capable of its full capacity, so need to avoid any sharp bends, kinks or crushing, so basically don't try to get it down the cavity as this is almost guaranteed to happen.

Have you considered fibre for this?

Beefy · May 11, 2020

davesparks said:
In which case you want it capable of its full capacity, so need to avoid any sharp bends, kinks or crushing, so basically don't try to get it down the cavity as this is almost guaranteed to happen.

Have you considered fibre for this?

Thanks - Yeah, The kinks are my biggest concern. I've got the thick, double insulated S-FTP stuff, which i intended on protecting round corners using strain relief and smoothing edges, I have a lot of cable on hand so don't see the harm in trying tbh, it's just my time and filling the odd hole and as i decorating the whole house, it makes sense to do it now. My only real criteria has been to do it cheaply and functionally, The decision for copper over fibre was due to having a 1000m spool on hand for it. I've never laid fibre for residential use, but my experiences in enterprise would lead me to think it would have been a lot thinner but more prone to breakage due to the small runs and quick directional changes in installation in a house scenario. Also the kit i have largely dictates the networking format.

AJ16 · May 12, 2020

Beefy said:
Hi guys,

I know this is technially not a mains electrical question as it's regarding network cable (CAT7) rated for inwall installation. But my question follows the same theory. I'm looking at dropping a few network cables from the gable end of my wall in the loft down into a room on the 2nd floor. The wall in question is an externally facing wall. (End of terraced external wall)

In your experiences does the cavity from the loft gable end run into the 2nd floor cavity wall with no obstructions? (Wood, Brick, Mortar seperating the floors?) Does it also run down to the ground floor with no obstructions? Wasnt sure that as the loft was breeze block whether it would not run in parallel with the brick cavity?

My house was made in 1956 and has no in wall insulation. Any advice or experience people can share would be amazing before i core out a 50mm hole I've included a picture for a bit of context.

Thanks chaps!

I would be wary of small animals chewing the cable,out of sight. Conduit sounds a lot better, it’s plastic so easy to fit and cheap to buy.