Hi All,

I am a d.i.y.er seeking your kind advice/guidance adding a 13A double socket in a single-brick wall, opposite to ("back to back" with) an existing 13A double wall socket on the other side.

The existing circuit is a 2.5 mm2 radial on a 16A RCB supporting two 13A double sockets, to which I am adding a third on the end.

My question is, do the regulations require a steel (or other) conduit pipe between the backs of the two metal back-boxes, or is it permitted to simply run the cable through grommeted punch-holes and through the 14mm drilled hole?

I'm using sheathed 2.5 mm2 twin + earth cable, an off-cut from the same circuit which was left over by the Electrician who rewired the house.  

Attaching pic of the 14mm hole.

Many thanks, ian

Many thanks Lectrician, will remember to offset boxes next time. Take care, ian