Ring main 100 square metres?

[La Poste]

I have read in the regulations that a ring circuit can cover a floor space of 100 square metres.
I am re-wiring a bungalow at the moment and the floor space is 88 square metres.
I am using 2.5mm stranded singles and 1.5 mm earth.
I am feeding the singles down the existing conduit in the walls from the loft.
Although the ring is less than 100 square metres I am wondering if the equation will be correct due to the fact I have cable drops of 3 metres to each socket.
Does the 100 square metre rule apply if I have these cable drops?
The ring supplies 7 sockets and the kitchen will be on it's own separate circuit.
There are no heavy loads being drawn from any socket but this may change in the future.
Any advice would be most welcome.
Thanks.

 

[vambo]

id say that would be fine. Ive run bigger rings in T+E, because your using singles the current carrying capacity increases so there should be no bother.

 

[La Poste]

id say that would be fine. Ive run bigger rings in T+E, because your using singles the current carrying capacity increases so there should be no bother.

Magic.
That will make me sleep better tonight.
Cheers.

 

[Risteard]

The 100 square meters is a HISTORIC requirement. Therefore the requirement ended when the 16th Edition was replaced by the 17th Edition. (Look at the Corrigendum which inserts the word "Historically".)

Obviously so long as your Zs, voltage drop etc. is in order then you are fine.

 

[martysparky]

My GF lives in a 3 story house.. floor space= about 150 sq meters and its all in 2.5 T&E. One ring including the kitchen.

 

[ukpablo]

just split the ring if u have room on board, thefore if it trips, the whole bungalow does not lose its skts........thats what i would do!

 

[La Poste]

just split the ring if u have room on board, thefore if it trips, the whole bungalow does not lose its skts........thats what i would do!

I was thinking that but it's just 7 sockets, three rooms.
Kitchen on a separate ring and a little extension that I will run a radial too.
I'm thinking 2 rings may be excessive.
I have used singles in 20mm flexible conduit.
Don't ever try to put six singles in 20mm flexible conduit, three is the limit believe me I know.

 

[davelerave]

out of interest how many rooms on the ring
utility room ?

 

[La Poste]

out of interest how many rooms on the ring
utility room ?

The ring is three rooms and a socket in the hall. It comprises two bedrooms and a lounge.
The utility is a little extension I will run on a radial. It houses a washing machine and fridge freezer.
The kitchen will have it's own ring, a gas cooker so no heavy electric loads only sockets.
The means of earthing is a TT earth spike.
The supply is overhead.
The existing wiring is in a shocking state. A death trap.

 

[davelerave]

your alright so

just watch the utility in case it needs more

 

[La Poste]

your alright so

just watch the utility in case it needs more

Might make the utility a ring in it's own right.

 

[martysparky]

Might make the utility a ring in it's own right.

Sounds like your answer

 

[Jurasic Spark]

Don't ever try to put six singles in 20mm flexible conduit, three is the limit believe me I know.

How are you wiring the Ring if your not getting 6 in?

 

[pushrod]

I was thinking that but it's just 7 sockets, three rooms.
Kitchen on a separate ring and a little extension that I will run a radial too.
I'm thinking 2 rings may be excessive.
I have used singles in 20mm flexible conduit.
Don't ever try to put six singles in 20mm flexible conduit, three is the limit believe me I know.

Just a reminder if you are putting 2 circuits in the same conduit then you are derating the cable's current carrying capacity by 20%

 

[La Poste]

How are you wiring the Ring if your not getting 6 in?

Right let me explain.
The conduit in the walls goes from the socket at floor level up to the loft.
If viewed from the loft you can see this wall conduit come up through the ceiling.
In the loft I have fed 20mm flexible conduit from the DB to the part of the loft where the wall conduit for socket number 1 is exposed IE it comes through the ceiling.
From there I have fed another bit of flexible conduit from the exposed wall conduit of socket number 1 to the exposed wall conduit of socket number 2.
From there I have fed a flexible conduit from the exposed wall conduit of socket 2 to socket 3 and so on back to the DB.
So I have flexible conduit in the loft housing three cables but when fed through the wall to the socket the wall conduit houses six cables.
One big ring.

Just a reminder if you are putting 2 circuits in the same conduit then you are derating the cable's current carrying capacity by 20%

Good point.
Does a ring count as two circuits ? The six cables are for one ring.
The six cables are running in the metal conduit inside the wall from the loft to the sockets.