Outdoor socket to ring main?

[AMEdinburgh]

I wouldn't do away with underfloor access as there are water and gas pipes as well as mains, telephone and data cabling under the floor in this and other rooms accessed from the trap. I appreciate your point though, as everything under the floor becomes inaccessible then. Assuming the trap is there, the junction box is deemed accessible - correct?

 

[ban-all-sheds]

Yes.

What happens to that JB when laminate flooring or tiles are installed?.....

Then it becomes inaccessible due to the actions of the person laying the flooring - not the fault of, and nothing to do with, the person who installed the JB. In exactly the same way that cables in a loft could be correctly sized until someone covers them in insulation

 

[pcsparky]

OK, lots of good advice here. I do have access to where the junction box could be fitted through a trap that I previously created next to these sockets and as long as we are in this house (probably till my coffin is required) we will not be covering the access with hard flooring as it's a lounge and we hate the stuff.

I can't connect from the back of one of the sockets because they are on a different wall to the outside wall that I need.

Disregarding how I take the power outside, is the rest of the plan OK? I.e From the RCB covered ring main to an outside (accessible) FCU then underground with SWA to an outside socket?