Running Mains (and LV/network) across a path


Postby brislex » Mon Nov 30, 2009 6:30 pm

Hi,

I'm about to have a fairly detailed discussion with my esteemed local sparky, but before I get him over (and scare him off) I'm trying to figure out some cable runs. I've been searching google and this forum for info on buried cable, and it all seems to say ~500mm depth required in soil, but I haven't seen anything clear about concrete.

My house is surrounded by a concrete path - hard to get under.

Is it permissible to chase an SWA + some low voltage stuff into a channel cut in the path, and then mortar over the channel? The regs seem to say it's got to be protected from reasonable movement - what is reasonable in a concrete path?

The location is about 2ft of path next to the house (and conveniently, the consumer unit). In short, the concrete isn't going to move (and there will be a small amount of cable going up the wall that should show where the tiny trench is). I know this is notifiable (will be done by pro), it's just I need to buy the light fittings ahead of time (or not, if I can't get the cable to them).

On an unrelated note, in the Part P doc, Additional notes to table 1, it suggests that outdoor lights attached to the wall are not notifiable if there are no exposed connections? Whats the precise meaning of exposed connections - can I run a cable straight through the wall, to the fitting, and not notify?
brislex
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Postby sparx » Thu Dec 03, 2009 8:33 pm

Hi, regs don't state min depths, principle is to avoid damage or/& someone 'finding' a cable unexpectedly!
For normal 'soft dig' situations eg under lawn or flower bed etc idea is to go deeper than some one digging over with a fork / spade etc, at which depth they should discover a yellow marker tape which you will have laid some way above the cable.
Whilst it is ok to chase a Steel wire armoured cable into concrete there is a problem at the edge of the path in that how do you get from above path to say 550mm down without some one with an edging tool cutting into cable.

As path only 2 feet wide why not dig trench upto path edge at full depth, small tunnel under as far as possible with garden trowel etc.

drill/break a hole against house side of path and with piece of tube or similar, bore down and with a garden hose in top hole and tube up 'tunnel' it is quite possible to make a mini tunnel to pass cables through.

Sounds worse than it is & I have done this several times before.
regards Sparx
sparx
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Postby brislex » Thu Dec 03, 2009 9:40 pm

Thanks for the full response,sparx. I didn't think of tunneling (or indeed edging tools striking the cable on the way down).

I think that'll work really nicely - there's even a crack in the path in the right place.

(I'll be getting an electrician in anyway to join it up, but this way I can dig the trench and tunnel (and buy the lights alongside a related job).
brislex
Posts: 2
Joined: Mon Nov 30, 2009 4:55 pm


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