I'm Installing thick Celotex in the garage using metal dry-lining studs set away from walls. Plasterboard over. There is a mains outlet which I need to extend away from the wall. What's the best way of doing this ?
Use a dry lining box set into the plasterboard. You might need to move the socket up/down/sideways a bit to make the cable reach, try not to extend the cable if you can avoid it.
You can take the plaster/render off the wall to expose the oval conduit/capping. You can then move the socket higher on the new wall. This is basic stuff. If you don't feel comfortable doing it, a sparky would do this quickly and easily and for you. Ideal opportunity to add additional sockets too.
Having no joint is by far the best option. You've been advised that in the first post, and subsequent ones. I have tried to advise of methods to achieve this, I have not trolled you. Your answers were not descriptive or full. You didn't help yourself.
I'm NO troll... Lost my connection again, to finish my reply, which was almost same as Lec reply, I also would prefered new drops, over having to join cables.
Having no joint is the best option, but there's no real problem in extending the cables. Especially when using maintenance free joints.