Electric shower wiring UK Regs do you have to use 10mm t+e cable now or can u still use 6mm?

Question

Don't all shout at me you have to be part P approved , I have no intention of wiring a shower I am only interested in whether it is still ok to wire a shower in 6mm sq cable. You used to be allowed 6mm on up to a 10.8 kw shower as long as your cable run was less than 18m and clipped direct to surface or inside plaster but has the new regs changed all this , I would be grateful for any one who def knows the new wiring regs to answer this perhaps someone who has just completed the 17th edition course Thanks ps I am a retired electrician who has hung up his tools for good!

Answer 1

yes 10mm

Answer 2

depends on Kw on shower, anything over 8.5kw use 10 mm csa as no diversity is allowed