Crimping and plastering over?

[DNS1]

Asked about this a while back, but read a few things since that have made me wonder if I was doing the right thing...

Got to join 2 pieces of T+E in the middle of a wall for a light switch. The rest of the cabling is plastered over. I'm intending to plaster over the joint too when it's made (currently it's a joint box hanging out a hole in the wall)

I don't want to have to leave it accessible (don't want a box/blanking plate halfway up the wall) so planned to crimp and sleeve, then plaster in.

Was told a while back that this method was compliant, but now I'm not so sure (read a few posts on another forum).

Any tips would be much appreciated. I'm not a pro sparks (obviously!) but intend to be one in few years so want to make sure I get these things right from the beginning.

 

[Darkwood]

No, looks like normal heat shrink but when you heat it up the inside goes well...........sticky! Its "adhesive lined". Forms a nice "stuck" joint against the cable sheath. For instance RS stock number 157-3795 - not saying this particular one -just an example, someone's bound to kick off over the dielectric strength! I can imagine this would help guard against the damp plaster getting in.

Yes self sealing i mentioned it in earlier post to give moisture tight sleeve, thought you'd found a new material then that i missed, luckily im still level with technology