Earthing problem

[js.b1]

1 - There is no requirement to u/g existing wiring to current regs.

- If the electrical install is safe, that is all that is required.

I would not be happy with Class-1 metal backboxes without a CPC. As suggested use a M3.5 nylon screw or see #3 below.

2 - NICEIC etc do a PDF about light circuits without CPC

- States WR & BR are not retrospective

- States lighting circuits should have Class-II switch/fittings

3 - Class-II FLUSH PVC backboxes do exist

- MK EGA, MK ESU/9/ML

- They are very hard to get hold of, but do exist

- Direct substitute for metal backbox

4 - When each room is redecorated fit oval conduit drops

- It is then a simple matter of a cable down a tube "forever"

5 - Check the loft for spare wallpaper, you never know

You can convert each light drop to oval & new CPC cable:

- Power off

- Cut the wallpaper-only 1in wide in the middle

- Peel back the wallpaper to ceiling

- Cut a 16mm slot thro the plaster

- Fit in the oval conduit

- Plaster not quite flush to hold, let it go off

- Plaster flush using a 1" scraper to level perfectly

- Use a piece of 1" wide D-Flat wood to cover

- Paint to match the wallpaper accordingly

Some people run the D-Flat wood to the floor or even use a 1G width version. Done right it will fit in quite well as "part of the fabric".

Wickes co uk do D-Flat wood right up to very wide - something like

110x6mm, Perfect to "architrave" a wall, not so pricey.

When you redecorate you simply remove the D-Flat wood. It gives you a migration path rather than "destruction path".

[Farmer Giles]

Superb reply, many thanks. I think that the approach that I will adopt is to make absolutely sure that the installation is safe, in the first instance - check that everything is class II, fit nylon screws, etc - then rewire each of the drops as each room is redecorated. Because my relative (my son, actually) has only recently moved into the property - and it does need to be, and will be, redecorated throughout - that would seem to be the best way to proceed. Because the loft of the bungalow is fairly spacious and accessable, I think that I'll run new twin and earth to the light fittings, rather than just a cpc - would it be permissable for me to do that under Part P? It's not a big property, with no more than 10 light fittings, so would 1mm cable be acceptable, or would you recommend 1.5mm?

[Farmer Giles]

Thanks, I'll check that out. Probably be trickier to locate if that's the case.

[js.b1]

Prudent and simple.

Yes, even in a Bathroom or Kitchen if via the same route. The ODPM document says "circuit" and circuit is defined under BS7671 as that protected by a Circuit Protective Device (fuse, MCB, RCBO). Plus in any case you are doing this progressively over time, and thus each part is considered separate.

What I would do is...

- Replace the supply cabling to each ceiling rose now

- Replace the ceiling rose where necessary

I say that because you may find the cable is degraded through overheated connections, junction boxes in the loft, or poor strain relief on dated ceiling roses, or lack of high temperature cable for ceiling rose drops. Lots of things get skimped over the decades re ignorance or simply predating current regulations.

No-one is going to complain about improving safety, but make sure it is improved :-) With regard to that, do not overtighten screw terminals on FTE 1.5mm cable - the CPC is still 1.0mm which is easily "bissected then snaps when flexed". TLC does the temperature resistant cable drops from ceiling roses.

Technically to comply with Part L a %age of your ceiling roses should make mandatory fluorescent light bulbs, ie, the 4-pin PL type. Those fittings tend to be very expensive (I think MK were =A318 at one point) which is just racketeering.

Check carefully any dimmers, some old ones were not of a particularly good design. MK can be had cheaply on Ebay if you look around and check feedback.

If the cable is *surrounded* in insulation you need to use 1.5mm

6242BH BS7211 (XLPE), Screwfix sell this (Prysmian cable). This cable is hard to work with re bending & stripping.

In most instances cable is *contacting joists or ceiling on one side* so you can use 1.0mm 6242YH (PVC), Screwfix and anywhere else sells standard PVC stuff.

Personally I would use 1.5mm as it is more robust for not a lot more money.

If the loft has not got 220mm+ or whatever insulation in it, book it in before next winter (or the summer re bake-thro :-)

[js.b1]

Part P document, SI2006.

p7 - When not necessary to involve building control bodies. b. The proposed electrical installation work is non-notifiable work of the type described in Table 1 and does not include the provision of a new circuit (see schedule 2B of the Regulations).

--- "of the type" is a broad catch-all for any basic maintenance.

--- basically you can't add a new circuit.

p8 - Replacing the cable for a single circuit only, where damaged, for example, by fire, rodent or impact.

--- BS7671 16th p19 defines circuit as "an assembly of electrical equipment supplied from the same origin and protected against overcurrent by the same protective device(s)."

--- so no problem replacing cables in one go, or progressively as you redecorate each room.

You can replace any cable, even in a kitchen or bathroom or across a garden (SWA). That also means you can replace some previous bodge of FTE through conduit across a garden with SWA, and also upgrade a found-to-be inadequate cable such as 4mm to a standalone cooker that someone skimped on or ignored.

Garages & sheds are not special locations once inside.

p7 - Additional notes b. Replacement, repair and maintenance jobs are generally not notifiable, even if carried out in a kitchen or special location or associated with a special installation.

You can replace any enclosure, be it a backbox in a kitchen thro steam damage (kettle, solid brick wall) to a consumer unit box. You can not however install new final circuits.

Someday I will break SI2006 by moving the hall lights onto the smoke alarm circuit. The hall lights are currently wired on the upstairs lighting circuit, so if the hall incandescent blows you lose the upstairs lights and can not see to get downstairs (due to window position & curtains downstairs). I dislike emergency lighting as they always tend to overheat (brown casing, even Legrand) & fail on me when needed. Since the smoke is RCBO protected the hall lights on the same circuit is a better indication of a tripped RCBO.

[ARWadsworth]

Technically to comply with Part L a %age of your ceiling roses should make mandatory fluorescent light bulbs, ie, the 4-pin PL type. Those fittings tend to be very expensive (I think MK were £18 at one point) which is just racketeering.

Does Part L apply on a rewire?

Cheers

Adam

[js.b1]

Dunno... actually it probably does to a Rewire. However this is not a rewire, it is a progressive repair.

I do not believe those special fittings are necessary - they are not particularly reliable, very expensive and money could be better spent on better bulbs or an extra smoke alarm :-)