Extending Ring Main into Conservatory Boxes & Trunking

[monkeysDIY]

Hi,
Apologies if this is listed already, looked fairly hard.

I have a conservatory (not yet plastered or floored) and am planning the electrics.

What is the recommended twin socket box depth for thermal block walls so as to sit flush? Also there is a perfect joint in ring main I can take either side of the door... How should I run this through the walls, 20mm conduit? How do I then run wiring to boxes, can I just cable to wall at what height or use a trunking?

All will be plastered and heated floor is being added.

 

[sparkwright]

Double metal boxes of a minimum depth of 25 mm deep can be used.
flush into the blockwork leaving about 12 mm (no more) sticking out to allow for render. about 18 mm sticking out for dry-line.

Cable in 20 mm conduit can be laid on the floor away from floor heating etc, and then conduit up the walls to the sockets. make sure you use grommets.

what is the perfect joint in the ring main?

 

[monkeysDIY]

Perfect joint = 2 x T&E going to bedroom above and joinging at a surplus socket!!
Should I sink the conduit into the walls/ floor?
I am laying 50mm of insulation onto floor for underfloor heating.
WIll that black plastic 20mm tubing be strong enough for tiled floor etc?
Thanks

 

[sparkwright]

don't sink conduit into floor.
screed over it.

sink the conduit into the wall so you can plaster over it successfully.

 

[sparkwright]

will the new sockets be directly on the ring circuit
ie
will you be extending the ring circuit?

this is far better than just running spurs.

 

[monkeysDIY]

Extending the ring via breaking it and attaching first box then linking last box back to break.

So I run a loop around floor of conduit and channel pipes up into wall boxes?
How best do I run the wire through house wall, I will have to bridge cavity. Can I drill 20mm hole and poke conduit through?

 

[1john]

Extending the ring via breaking it and attaching first box then linking last box back to break.

So I run a loop around floor of conduit and channel pipes up into wall boxes?
How best do I run the wire through house wall, I will have to bridge cavity. Can I drill 20mm hole and poke conduit through?

you can try it may be a bit tight, a 25mm hole may be easier and silicone around after.

 

[monkeysDIY]

Thanks.
So with the boxes on the wall how far can I run the conduit down? My floor is at 75mm below finished level currently ( I am having 50mm insulation, 8mm of mat and adhesive and 17mm of tile)
I understand that I must run conduit vertically down for safe zone but is under finished floor level Ok for horizontal running of conduit? Also what height/ point is best to run into house?
Thanks

 

[ban-all-sheds]

1) Cables should be at least 50mm below FFL.

2) What's under the insulation - concrete slab?

 

[monkeysDIY]

Yes, concrete slab, nice and fresh with kitten paw prints!!!!

As this slab is below the house fllor by 50mm how/where should I enter house?

Thanks

 

[monkeysDIY]

Also what is the spec for Safe Zone and corners?
Thanks