Chasing Cables - remove ceiling, or horizontal chasing?

[George Hartshorn]

Hello,

I have a basement flat which currently has surface mounted sockets.

I want to chase all of these in whilst I am refurbing it, and when my electrician came round he mentioned that I would need to remove the ceiling to put all of the cables in, and then chase down the walls to where I want the sockets.

I can remove the ceiling myself but it's a messy job - and putting a new plaster board ceiling up & skimming will be expensive, so i'm looking at other options first.

Is there any reason why I can't chase horizontally into the walls to avoid going in the ceiling?

There would be quite a few cables running in the channels out of the DB, is there a max width that you can chase before you risk the structure of the wall?

Thanks in advance

 

[oldbutnotdead]

Horizontal chases are fine as long as they are within the safe zones established by sockets, switches etc.
Chase depth max 1/3 of the wall thickness, no limit i know of on width.

 

[BS3036]

Chase depth max 1/3 of the wall thickness, no limit i know of on width.

I recall 1/6th for horizontal chases. Quite important for obvious reasons.

 

[rsgaz]

depth max 1/3

For a horizontal chase, it's one sixth. Which is why it's not always do-able.

OP, You can run cables round the top 150mm of the wall and drop down to accessories. If you're re-wiring, doesn't the ceiling need to come down in places anyway for lighting cables(and/or moving/adding lights)?

 

[oldbutnotdead]

I recall 1/6th for horizontal chases. Quite important for obvious reasons.

That would make sense. TBH most plastered walls there's enough plaster to hide the cables...

 

[JohnD]

he mentioned that I would need to remove the ceiling to put all of the cables in, and then chase down the walls to where I want the sockets.

"need" is not true.

taking down a ceiling is a great deal of work, and if the house is old with L&P, extremely dirty.

if you are obliged to take the ceiling down for some other reason, and are going to reinstate it with improved soundproofing and fire protection, you may as well run new ceiling lighting cables.

But for sockets, it makes much more sense to channel horizontally around the walls. No need to keep going up and down. Use oval conduit and it is very easy to add more at whim.

 

[George Hartshorn]

Thanks for the advice so far

There's no need to rewire any of the lighting, it's just all of the sockets are surface mounted which is quite ugly.

I was thinking about cornicing or something similar to hide it if we ran horizontally near the ceiling but my electrician said there would probably be too much cable to hide behind it, but if there's no restrictions on width then chasing horizontally may just be the ticket.

Having said that, now that i'm spending time in the flat i'm hearing a lot of noise coming from upstairs. Maybe it might be a good time to add a bit of additional sound proofing!

 

[rsgaz]

but if there's no restrictions on width

Up at ceiling level you have 150mm to play with.

Going round the walls at socket height, the prescribed zone the cable can be in is the height of the socket, which is 87mm.

There would be quite a few cables running in the channels out of the DB

Why so many cables? If you use a horizontal chase at socket height, any extra cables which are just passing by/through, can't be just snuck into these prescribed zones, they would technically be against the rules. (522.6.202). At ceiling level there is no restriction on which cables can be there.

 

[JohnD]

you will have lots of sockets in every room in the house (except the bathroom) so it makes sense to chase horizontally for them.

the kitchen might have a cooker circuit, and possibly a dedicated freezer circuit.

the lights you are not concerned about.

Phones, LAN, burglar alarm, aerial, speakers are not "electrical" for these purposes

how many other circuits are running round the flat?

I get the impression you have no access under the floor.

 

[sparkwright]

Clipping the cables straight to the wall just below the ceiling and fitting COVING should make the work easier.

 

[jj4091]

If it is a basement will you not have to be careful of damaging any tanking that has been done.