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

[Beefy]

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!

 

[Pennywise]

Personally id be drilling out of the loft and putting some conduit on the outside wall then drilling in at the desired height low level in the room and cutting a single or double box out. that age of building the cavity is going to be very tight, by all means maybe cut a single back box into the wall in the 2nd floor room go through into the cavity see if its possible, if not cut a double box in over the single you've cut already so you can get a fixing.

 

[SJD]

There may well be a clear route from the loft to the second floor room, but you might also find lots of builders debris in the way, that just got dropped or swept into the cavity during construction.

 

[Beefy]

Personally id be drilling out of the loft and putting some conduit on the outside wall then drilling in at the desired height low level in the room and cutting a single or double box out. that age of building the cavity is going to be very tight, by all means maybe cut a single back box into the wall in the 2nd floor room go through into the cavity see if its possible, if not cut a double box so you can get a fixing.

ing r
Thanks Pennywise, i was considering this, just thought cavity would be neater with less cable showing. (And i dont have a 5m ladder!) Do you have any good recommendation for the conduit? I opened a 2nd question after this one asking for peoples experiences of PVC conduit for this sort of job as everything i saw wasn't UV protected and had no good water sealing parts and ratings. 10 cables is also on the thicker side of conduit i suppose?
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There may well be a clear route from the loft to the second floor room, but you might also find lots of builders debris that just gets dropped or swept into the cavity during construction.

Thanks SJD, This was my fear. It's next to a chimney breast that you can see in the pic. I was considering dropped it down that as it's unused!! lol Bad idea?

 

[Pennywise]

ing r
Thanks Pennywise, i was considering this, just thought cavity would be neater with less cable showing. (And i dont have a 5m ladder!) Do you have any good recommendation for the conduit? I opened a 2nd question after this one asking for peoples experiences of PVC conduit for this sort of job as everything i saw wasn't UV protected and had no good water sealing parts and ratings. 10 cables is also on the thicker side of conduit i suppose?
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Thanks SJD, This was my fear. It's next to a chimney breast that you can see in the pic. I was considering dropped it down that as it's unused!! lol Bad idea?

Dont get me wrong getting it down the cavity is far neater, im just looking at it from an effort point of view but then if this is your own home and not a paying job and you've got the time its worth spending the time doing some exploratory work. I only use Marshall Tufflex conduit, used plenty of other brands over the years but always go back. Also 10 cat7 is going to need maybe 2 runs of 25mm conduit, cant get away with anything less than cat7 its more than double the price of cat5.

 

[plugsandsparks]

You can use solvent waste pipe. You can get it black and white, its UV stable and when glued is as water tight as you like...

 

[pirate]

I feel that the chances of old builders debris at that level is fairly low. Also, probably no "fire stops" in the cavity, so actually I would just go for dropping the cat cable "as is"...it ain't gonna kill anyone. and will probably work just fine.

 

[Beefy]

Dont get me wrong getting it down the cavity is far neater, im just looking at it from an effort point of view but then if this is your own home and not a paying job and you've got the time its worth spending the time doing some exploratory work. I only use Marshall Tufflex conduit, used plenty of other brands over the years but always go back. Also 10 cat7 is going to need maybe 2 runs of 25mm conduit, cant get away with anything less than cat7 its more than double the price of cat5.

Thanks i'll look into there product line, is it rated for outdoor use? I had a quick browse and a lot if it looks to be internal conduit products? Have you used it outside to good effect?

 

[littlespark]

I’d be tempted for surface trunking, or change where you need the cables so they come down inside a cupboard and through the wall.
Too much hassle down a cavity. Wall ties, jaggy mortar...

 

[Beefy]

You can use solvent waste pipe. You can get it black and white, its UV stable and when glued is as water tight as you like...

I hear that this is good stuff. Do you have a good brand in mind that offer T pieces and termination options? technically i'd be running a vertical piece from loft to ground floor and a few runs horizontally to the rooms is all.

 

[pirate]

Ah...just seen this is a combined thread. Honestly, cat cable is not a problem externally. Plugsnsparks suggested solvent waste pipe...it's fine, as is any decent quality plastic conduit. It's all about appearance and neatness of you have multiple cables. Choose whatever suits.

 

[Beefy]

I’d be tempted for surface trunking, or change where you need the cables so they come down inside a cupboard and through the wall.
Too much hassle down a cavity. Wall ties, jaggy mortar...

Good plan. Thanks everyone some good info.

 

[freddo]

You can buy PVC conduits and some boxes and fittings up to 2". Not easy to find though.

 

[davesparks]

I wouldn't run cat7 in a cavity, or any network cable, damage, kinks, or over bending can all harm their ability to perform at their rated speed.

Assuming that you are installing cat7 because you need cat7 speeds, and not just because it sounds like the latest thing so you must have it, then you need to take care to ensure it is not kinked or damaged in installation and it is always handled with care and in accordance with manufacturers instructions.

 

[Beefy]

I wouldn't run cat7 in a cavity, or any network cable, damage, kinks, or over bending can all harm their ability to perform at their rated speed.

Assuming that you are installing cat7 because you need cat7 speeds, and not just because it sounds like the latest thing so you must have it, then you need to take care to ensure it is not kinked or damaged in installation and it is always handled with care and in accordance with manufacturers instructions.

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.
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You can buy PVC conduits and some boxes and fittings up to 2". Not easy to find though.

Yeah i saw Does anyone have any good brands and products for this purpose? I had a look a few weeks ago and even called a few suppliers and some couldn't guarantee me it wouldn't fall apart from UV damage within 2-3 years Getting black over white was also very tough in the larger sizes. The only guarantees we're with using soil tubing's but the diameters of tubes were very big if i remember correctly.