I was going to put a doble socket spur off a double socket in my sons room and I assume the circuit is on a ring. I was going to connect via the back of the original socket but I noticed that the ring passed under the floor where I was putting the new one. I stripped back the insulation on the wire on the circuit without cutting through and put it through a 30A JB and used 2.5T&E for the spur. The cable was sleeved and sunk into the wall up into the box. The JB will be accessible in future and its postion is clearly marked on the floor boards above it. All I really want to know is, does the work I have done sound OK or does anyone really recommend that I do it properly.