Back to basics here, but just want to check I'm not going mad. Was installing a circuit for a boiler yesterday on a new build (it had been accidentally omitted apparently) , and I noticed there was another 'spark' working in the living room. I idled over and asked what he was up to. He said he was adding more sockets as only three had been installed initially. I assumed he would be extending the ring....easy enough to do as loads of floorboards still not fitted. However, he seemed to be using MF JBs under the floorboards. I noticed that the one he had just done had four cables going into it. When he'd gone I had a closer look, and he'd broken into the ring and had two spurs coming out of the JB to double sockets. I've just seen him and asked him about it, and he's adamant it's fine to do this from a JB but not from a socket. I think not! Anyone?