I'm planning on putting down additional insulation and boarding in our loft, however I have run into the problem of the current wiring for the first floor lights, which is currently at a level that would be covered by the new insulation (obviously a no-no) and which doesn't appear to have enough slack to simply run on top of the new level of insulation. In any case I wouldn't want the wires to be hidden under the boarding and so I was considering running new wiring along the loft rafters so that it would be well out of the way and using vertical lengths of wood over where the wires need to drop to ceiling level for the light fixtures and switches.
A couple of things are concerning me and any advice would be greatly appreciated.
1) The current wiring appears to be in a loop - I can find one point where two wires come up from inside a wall and go off in opposite directions. Is it necessary for it to be in a loop through each light fitting or could I have a smaller loop with a spur off to each fitting?
2) The wiring only appears to be 2-core (ie un-earthed). Presumably any new wires would have to be earthed, though this would mean new wires down to the consumer box?