BigWallop wrote:

My personal choice on this would be a separate RCD protected supply to the
radial wiring that enters the wet room. It's because of the wet room
situation, and the fact you have electric UFH and drying elements in close
proximity to your, most likely, bare extremities.

I would supply a stand alone RCD unit with T&E cable of 4 mm csa' from a 15
or 20 Amps MCB in the main consumer unit. I'd then take radial wiring in
T&E 2.5 mm csa' from the RCD unit to the appliances as you say above.

I personally feel safer knowing that if a fault does occur, say in some
inaccessible point, then the RCD would make sure that the supply is tripped
off without putting anyone in danger while being wet in the wet room.

Theyre not perfect, but they generally will. I'd sooner put towel rail
and ufh on the CH myself. You wont need them in summer after all. And
run cost will be much lower.


This also separates the new heating circuit you install in the wet room from
the rest of the house, and it saves time in having to check which part of
the ring circuit is actually causing the fault.

I would also make sure that all metal parts in the wet room are double earth
bonded with at least a 4 mm csa' conductor right back to the earth bar on
the main consumer unit.

they should normally be equipotential bonded rather than earth bonded.
Double bonding would only be needed if your house suffered antisafety
vandals. Bear in mind everything is bonded once or twice already
anyway, always by CPC and often by copper piping as well. Plus you have
mcb and RCD protection.


As for the flex outlet plates. Yes it can be used in this type of
situation, but make sure you smear some sealant around the joint between it
and the wall to stop water droplets from getting in behind it. In an
installation such as this, I personally use plain blanking plates with a
knock out on one edge. This is so a I can place the knock out pointing
downward which then allows the flex to hang so moisture can't run back up it
and into the gubbins inside. Finished with some sealant around the gap
between wall and plate and it usually lasts for many years without causing
problems.

I'm a bit more hesitant about that. I would use properly rated kit. Any
gap at all and youve got hot 100% RH air wandering into a colder
pattress, its a recipe for condensation on the electrical connections.
You can silicone the wall junction, but theres the cable outlet as
well.


NT