Confirmation of regs and a chasing question, vert or horiz

[DarrenThomas]

Forgive my question. I am confident that i know the answer but would much rather check first.

I am about to move into my first house which has a concrete floor down stairs and not enough sockets because of its age (1955 - Council). As far as i have been able to determine from this site and others, i am able to modify an existing ring to add more sockets without needing to get the work certified.

However in the wiki has an entry which has concerned me.

[code:1]At the time of writing (April 2006), the following work was classed as not needing notification to LABC:

1. Work consisting of -

(a) replacing any fixed electrical equipment which does
not include the provision of—

(i) any new fixed cabling; or

(ii) a consumer unit;
[/code:1]

Does this entry mean that i can only modify an existing circuit if i don't add any new cable?

The second part of my post is regarding the chasing of said cables. I am aware that the safe zones are within 150mm of the corner or the ceiling as well as horizontally and vertically from any socket/switch. I also get the impression that the sparks on here dont much like horizontal chasing (im guessing from a wall stabilty point of view?).

With my livingroom i was planning on adding two gang sockets in each chimney alcove as well as 2 gangs on the opposite wall totaling 6 for the whole room. My plan for the alcove sockets was to drop from the ceiling to the first socket, and then chase horizontally about 2ft to the next socket and then go back up to the ceiling. While in a safe zone, would you consider this acceptable?

Would i be better to have the two gang sockets next to each other, meaning that the safe zone would essentially be one vertical area twice as large as normal and run a single chase in this zone.

Thanks for any replies, i have tried to find what i am after in the search but i couldn't be sure without asking myself.

 

[flameport]

Adding sockets / cable to an existing circuit is NOT notifiable, unless it is in a kitchen or bathroom. The section quoted only applies when replacing an item such as an electric shower.

Chases can be vertical or horizontal from a socket outlet. If your walls are solid, the depth of any chase must be less than 1/6 of the wall thickness (otherwise the structure of the wall would be affected). Plaster is not included as part of the wall thickness.

If your walls are hollow blocks, horizontal chases are really out of the question as removing the front skin of the block would only leave the rear skin to support the wall (which it almost certainly would not do).
If they are hollow, it will be easier to clip the wires and backboxes to the surface and put plasterboard over the whole wall.

For the sockets what you suggest is acceptable, although it will be much easier to have a slightly wider chase to the first socket, then one cable goes into the 1st one, the other continues uncut through the back of the first socket and goes horizontally to the second one, then a short piece returns from the second socket to the first. Both are part of the ring but only one vertical chase required, and you can have the sockets as far apart as required.

 

[PrenticeBoyofDerry]

Vertical chases are one third of wall ie 150mm depth of wall, less than 50mm chase

 

[spark1]

Darren . the work you intend to do may well not be notifiable, it does however, still have to comply with the building regulations...some of your questions relate toPART A Structure. you may wish to study the guidance notes on this section before any channelling of walls etc.
In order to comply with the Building Regs your Electrical work also has to be compliant ,and an acceptable criteria is ensuring compliance with B.S 7671 2008. Have you carried out any checks on your existing Electrics...i.e Earthing - Main Bonding--Fusebox {RCD Protection} -Ring Continuity--Insulation Resistance-Polarity -E.F.L.I. The safety of your proposed Alterations Relies upon Confirmation that these tests are satisfactory.

 

[DarrenThomas]

Thanks for the replies.

I'll be checking through the Part A sction you mentioned and will be sure to have everything checked before i start (at the rate the solicitors are going it could still be months ).

 

[ban-all-sheds]

Adding sockets / cable to an existing circuit is NOT notifiable, unless it is in a kitchen or bathroom. The section quoted only applies when replacing an item such as an electric shower.

Yo.

Darren - the way it works is that you read down Schedule 2B and stop when you find a match with what you are doing, not when you find something which doesn't match. Only if you get to the end of 2B without finding a match does it mean the work is notifiable.

In your case you'll find a match at 2(c)(ii).

 

[holmslaw]

..

 

[EddieJT]

LABC?

Are you a Croydon man Darren? If so me too, and I also have an all concrete place.

Mine was built in the 60s and had 1 single socket per room. Luckily conduit was used throughout, so I was able to use this for the rewire. Then had to chase out floors to put in extra sockets. I didn't do any horizontal chasing though.

 

[ColJack]

Vertical chases are one third of wall ie 150mm depth of wall, less than 50mm chase

You're avin a larf.

You go cutting 50mm chases in a 150mm wall you'll end up with a trowel sticking out of your head, and a bill for repairing the damage.

And cutting long horizontal chase could bring the same result.

Chases should be as shallow as possible, just deep enough for the cable/protection to be flush with the brickwork.

according to my nice new green book ( electricians guide to the building regulations ), they're right..
vertical chases no more than 1/3rd the depth of the wall, horizontal, no more than 1/6th the depth..

 

[holmslaw]

..

 

[PrenticeBoyofDerry]

Vertical chases are one third of wall ie 150mm depth of wall, less than 50mm chase

You're avin a larf.

You go cutting 50mm chases in a 150mm wall you'll end up with a trowel sticking out of your head, and a bill for repairing the damage.

And cutting long horizontal chase could bring the same result.

Chases should be as shallow as possible, just deep enough for the cable/protection to be flush with the brickwork.

Should be but could be, hence the ie .I've got my hard hat on so come on the trowels.

 

[holmslaw]

..

 

[sparkyspike]

I've seen some crap MOD housing schemes, using 3' cinder blocks

When I first started working as a spark, I spent most of my time rewiring the old barracks in and around Aldershot. The walls were so thin, you couldn't fix a knock-out box with plugs and screws without coming out the other side, so we used bonding plaster instead. Apparently these houses were built as a stop gap with only a 15 year life expectancy. 30 years later and we were rewiring them! (Concrete ceilings too! Those were the days...)

 

[PrenticeBoyofDerry]

I've got my hard hat on so come on the trowels.

Don't forget your running shoes.

I've got some steely toed trainers

 

[DarrenThomas]

LABC?

Are you a Croydon man Darren? If so me too, and I also have an all concrete place.

Mine was built in the 60s and had 1 single socket per room. Luckily conduit was used throughout, so I was able to use this for the rewire. Then had to chase out floors to put in extra sockets. I didn't do any horizontal chasing though.

Indeed yes, grew up in Addiscombe but the house is out in Hooley (up the road from the BP Garage before you get to the M23).

After looking at my plans some more i have decided to not bother with horizontal chases. It would save me a little cable but would mean more chasing and therefore more filling in. for the sake of a few quids worth of cable it doesn't seem worth it.