cables in walls - horizontal from sockets?

[dennis]

You could put a dummy face plate with a note in it near the ceiling to mark where it starts.

[Lobster]

Actually, I happen to have a 'before' picture too, so here it is:

just a regular 13A spur, presumably for the TV (and no, the Daily Sport wasn't mine! I think it would have been a pro job, but can't be sure. Judging by the colour scheme (!) I would place it at pre-1970s, so as another poster as alluded to, maybe it was actually legal then.

David

[Tim Watts]

It's still in the 17th exactly as you say :)

[John Rumm]

Which is ok on new build, but often impossible to avoid on a rewire...

or RCD protect it at

[spamlet]

Not much choice if floor is concrete: just a couple of feet with the angle grinder fills whole house up with incredible amount of plaster dust though!

S

[John Rumm]

Well you can go up into the floor void above...

(wall chaser with dust extraction is significantly better BTW than an ordinary AG).

[spamlet]

Only needed to do it once so far John: I only do the odd one when say furniture - in this case a piano - prevents access to an existing socket. Otherwise I've tended to drill and chisel rather than use an angle grinder (old house mostly very very soft plaster), but in this spot the buggers had concreted up the wall under the plaster and I had nothing to cut it with but a borrowed angle grinder. I have to say I was pretty impressed by the total white out that a few seconds of cutting created! :-)

S

[John Rumm]

BTSTGTTS!

First time I tried it, I got about half way down a 4' chase in new plaster before I realised I could not see my hands 1' in front of my face anymore!

I would not repeat that exercise in an inhabited building again! The chaser however makes is no worse than using the SDS with a chisel bit.

[spamlet]

I didn't get the T-shirt, but it looks like when I get back on the ball I'll be in the market for some SDS gear, after all the praise it is getting here lately. :-) S

[John Rumm]

Best mess I ever made with an AG was helping a mate convert his integral garage. There came a point where we needed to cut a doorway through an existing external wall. Knowing what to expect I put on a disposable coverall (the sort with hood and everything), respirator, and visor, took a kw of flood lighting into the room and let them seal me in ;-) Cut most of the way through (i.e. max depth of a 9" grinder) from that side, then finished off with a single disc in a wall chaser from the other side (marked the corners of the doorway by drilling through first so we knew the cuts would align). I remember having to wait 10 mins for the dust to subside enough after cutting to make it safe to unseal the room!

[BruceB]

Which rule says >50mm from surface applies to ceilings?

522.6.6 relates to walls.

Regards Bruce

[David Robinson]

Thanks everyone for the advice.

The surprising thing about the existing (original, 1973, woefully inadequate) wiring is how neatly it's all installed. Though there is at least one point where cables are run diagonally. Very economical on use of copper.

Cheers, David.

[Dave Plowman (News)]

Do note if you intend using it for chasing walls to get one of the lightweight ones - which sadly usually means more expensive. Trust me. ;-)

[js.b1]

522.6.5 relates to ceilings & floors (p59 of the 17th OSG). Where a cable is installed under a floor or above a ceiling it shall be run in such a position that it is not liable to be damaged by contact with the floor or ceiling or the fixings thereof.

So the rule does not apply to cables run loose on ceilings.

However, consider a cable penetrating a joist and then running parallel to the joist along the ceiling - it is quite possible someone may screw into the joist using a stud detector and by chance catching the cable. An example would be a battery powered CO alarm or smoke alarm to the ceiling, or clothes airer, CO or smoke alarm, wireless camera or office style lowered on steel cables (can be great for hiding cable trays of networking cables :-)

[js.b1]

Go by dust extraction - which is a whole new thread, adventure & whiteout of its own.

I have used an arbor with diamond cutting disc in a 14V cordless (not mains!) drill to slot walls, with a helper running a vacuum cleaner nozzle catching the "very narrow & controlled jet of ejectile material". Very cheap, somewhat slower, but almost no mess, Miele will handle plaster ok - at least a very old battered Miele cleaner with everything broken off it has done so for several years.

[Andy Burns]

Downstairs of house was almost entirely out of action, I waited for a windy day, wedged open front door, back door, and internal doors thenlet rip with the AG, shopped out a full height breeze block wall in the porch, and "chased" all the drops for re-wiring the kitchen, looked like smoke belching out of kitchen door ...

[Steve Walker]

Unfortunately the accessory is vertically *above* the RSJs, and the ring is in the floor that they support.

I know where it is though, so I'll either do something if I rewire the extension or just tell the buyers when we move house.

SteveW