Cables in cavitys

[foxy1978]

Sorry if this has been asked before, but I had a look else where on this site and couldn’t really see anything.
What I would like to know is if its ok to run an armoured cable in a cavity wall if it is inside some sort of conduit.
I am building a shed in my back garden but my main board is at the front end of my house and my downstairs floor is concrete. I would like to come through the back of my house, through the cavity (obviously) and then run down the party wall. Is this possible? If not can anyone please suggest some other way. Thanks in advance.

 

[Lectrician]

When you say in the cavity, and then say through the cavity, which is it you really mean?

If you mean drilling a hole through the wall for the cable, then this is fine and no conduit is required. Best to drill at an angle downwards to prevent water ingress, and depending on the size of the cable, to suit the beding radius.

If you are talking about placing a cable inside a cavity, this is not meant to be done. Armoured is less likely to become damaged during install, but you are still going to be bridging the cavity which is not allowed. A cable passing through the cavity is fine, especially with a fall to the outside, as any moisture will be directed to the outside skin.

 

[foxy1978]

I mean both. Drilling a hole through the brick veneer bridging the cavity and then running along the party wall, inside the cavity. I stay in a semi-detatched house.

 

[Lectrician]

Ah, I see.

I wouldnt want to place a cable in the cavity between me and neighbour anyway. Just seems wrong to me.

How would you get the SWA in without risking damage to the cable? Do you have access tot he cavity to such an extend you can ensure there will be no damage?

Using conduit as an extra measure still does not make it acceptable, and I am not sure how you would even get the conduit into the cavity!


Whats going in your shed? What sort of load will you need?

 

[foxy1978]

Access to the cavity would not really be to much of a problem, so i am not to worried about that side of things. There would only be a couple of double sockets in the shed running power tools, garden equipment, maybe a small heater in the winter and 2 lights, 1 inside and 1 PIR outside. My shed is about 25 meters from my main board.