re-wiring an old house

[Becka]

this might be a dumb question.. but if you don't technically need conduit, does that mean that I could bury wires unprotected by conduit in new lime plaster? would save me a certain amount of hassle if I could as I'd need to find bendy conduit

 

[MdB]

I think that it is important to note in this thread that electrical work has to comply with Part P as follows:

Part P applies to all electrical installation work carried out in dwellings. However, you do not need to tell your local authority's Building Control department about:

* repairs and maintenance work or
* extra power points or lighting points or other alterations to existing circuits (except in specially defined areas such as a kitchen, bathroom or outdoors)

To comply, work has to be tested and a certificate given. If you come to sell a house and you don't have this certificate for new work then this can cause problems. New work is easy to see as it has brown and blue conductors rather than red and black.

Of course people still do their own DIY electrical work which is why I'm having to completely rewire my house as it is such a mess. Interestingly I was the first person to contact my local building control about doing this properly as a DIY job in the almost two years the rules have been in force. Fortunately they are happy for me to the installation (I'm EE trained) but testing has to be done jointly with someone who can sign off Part P.

 

[Becka]

I'm not rewiring.. just considering how to hide a wire that is already there.. hanging out of the wall at present as I removed the plasterbaord that was covering it.. the easiest hiding option is to tuck it into the plaster under the beam without conduit, but would the lime be likely to degrade the plastic?

 

[MdB]

Polystyrene is definitely a problem with cables but I've not heard of anything else being an issue. [I am not an expert on this]

 

[tony]

First of all your installation must comply with iee wiring regulations,

if your electrician has done this, you would be 95% complete on the part poo

part poo is about council notification, and building control etc, ( i think as it is not applicable in Scotland )
certain things are not required to be notified.

the only good thing about part poo, is that is has made electricans who never owned any test equipment go and buy some, for this alone part poo is good

Any decent electrician will certify any work that they do, either on a minor works certificate or a electrical installation certificate.

A periodic inspection report is a good one if you have just bought a house, as it will identify all electrical equipment/wiring that does not comply..

I,m not sure about the lime, just in case why dont you use a bit of capping, its only a couple of pounds from the big sheds, and will help protect the cable from the plasterers trowel..

best regards

tony

 

[Penners]

Same for water stopcock, on the consumers side of the stopcock.

Tony - does that apply if the water supply emerges from the ground in alkathene?

 

[MdB]

Same for water stopcock, on the consumers side of the stopcock.

Tony - does that apply if the water supply emerges from the ground in alkathene?

Yes. You are earthing the pipe work to the mains earth. You are not using the pipe work as the mains earth. The master earth will be supplied either by the electricity board or by a proper tested earthing spike into the ground. Pipe work into the ground is not considered good enough for an earth (mainly due to the problem of plastic pipe!)

 

[Penners]

You are earthing the pipe work to the mains earth. You are not using the pipe work as the mains earth.

Understood, MdB. Many thanks.

 

[tony]

yes, the mdpe incoming pipe will have a stopcock, the water main bond should be fitted as close as possible to the stopcock, on the consumers side ie the side that you can shut the water off to.

the only problem is when you have plastic pipe thru out the property with short bits of copper up to radiators, sinks etc.

you are concerned with what is inside the property with regards to earthing/bonding not what brings the water into the property.

similarly some old gas pipe used to have a earth conection on the pipe, this doesnt comply with the regulation, as many of the gas suppliers replace large section of old pipe with plastic pipe this means the cable isnt doing anything.


Before any electrical works takes place with regards to additions earthing and bonding must be checked first.

regards

tony

 

[Penners]

Thanks, Tony.

 

[Becka]

On reflection, if no-ones tried it already, the lime would worry me, after all, its kind of known for it's corrosiveness... in which case, can you get bendy conduit? the only stuff I've seen is in straight plastic sections (or metal sections which I've found in my walls occassionally) but I'd definatly need some curves...

 

[Lime]

On reflection, if no-ones tried it already, the lime would worry me, after all, its kind of known for it's corrosiveness... in which case, can you get bendy conduit? the only stuff I've seen is in straight plastic sections (or metal sections which I've found in my walls occassionally) but I'd definatly need some curves...

If you bury a body in lime you preserve it, not destroy or corrode it.

If the cable is in plaster it is always best to protect the sheath either with conduit or some similar cover.
Even polythene ribbon wrapped around the cable would give plenty of protection from the chemical effects, if any.

 

[Becka]

polythene ribbon? where would I get that?

 

[Becka]

and you learn something new every day.. I thought they always threw lime in plague pits etc so as to eat away the bodies quicker! on a completely differnt track, what was ther purpose of that then? to sterilise them? (tho they wouldn't have know what against then, way before pasteur and bacteria carbolic acid and antiseptics etc) some kind of odour control? sorry, complete change of track, I'm just a little puzzled

 

[NT]

It used to be true that metal fittings on unearthed lighting were a no-no, but unearthed double insulated metal light fittings are now accepted and quite common. So if you want metal fittings on very old wiring, look for the double square symbol [[]] on the light fittings. If present, they can be compliantly used on unearthed circuits. However I would not attach them to any pre-existing metal wiring accessory.

And to be honest, if you've got historic wiring its generally best left alone until replacement. Most is rubber insulated, and the rubber tends to crumble away when moved, causing a high risk of shorts, blown fuses, fire or shock. Old ashathene is ok to work on, as is early pvc, as long as neither contain rubber inner insulation. Old rubber cables of almost all types are really not ok to work on, even a quarter inch of movement can short them out.

1930s lead sheathed should be left alone, disconnected, or moved over to a low voltage supply. The outer earth conductor can become live on lead cables.

Pre 1920s wiring is generally an immediate danger, though some of it has plenty of character and can be run at low voltage.


NT

 

[NT]

Becka:

> this might be a dumb question.. but if you don't technically need conduit, does that mean that I could bury wires unprotected by conduit in new lime plaster? would save me a certain amount of hassle if I could as I'd need to find bendy conduit

Yes, this is standard practice. Wiring should stay within the permitted zones else additional conditions apply.



MdB:

> If you come to sell a house and you don't have this certificate for new work then this can cause problems.

That's what was initially expected, but it doesn't seem to be going that way. A buyer's solicitor may query absence of paperwork, but it is hard to find a buyer that pulls out of a house purchase or insists on retaining any money on this basis.


> Interestingly I was the first person to contact my local building control about doing this properly as a DIY job in the almost two years the rules have been in force.

I knew compliance was minimal, but didn't know it was quite that bad!

Blue/brown cable and Part P were not introduced at the same time, and there is a significant amount of red/black post part p work around.



Becka

> would the lime be likely to degrade the plastic?

Cable in plaster or filler is fine, with the exception of some plastic foams.

It might be worth mentioning that some old cable clips caused cable degradation. Be aware of this if youre ever tempted to use bottom end clips eg poundland, as there's no knowing what type of plastic they might be.



> sockets outside check out 471-16 in the wiring regulations- rcd protection is required

I thought you were discussing sockets indoors that could be used by appliances outside.


> for diagonal runs you cant use plastic conduit if its less than 50mm from surface as this is not a recognised cable route

Running cable outside the permitted zones with metal capping is a recognised and accepted method in the 16th edn.


NT

 

[tony]

Becka,

If you want bendy conduit try your local electrical wholesalers and ask for kopex or adaptaflex, both produce a flexible conduit that can be cut with a stanley knife to the desired length and then proper glands attached at the box end.

NT

Indoor or outdoor socket outlets that can be reasonably be expected to supply portable equipment outdoors MUST be protected by a 30MA rcd.Socket outlets installed out of doors must be of a weatherproof construction minimum IP54 and must ALWAYS be protected by a 30MA rcd

A cable installed in a wall or partition must be run in such a position ot otherwise protected that it is not liable to be damaged by contact with the wall structure or construction fixings

This is particularly important when the wall or partition is metal or part metal construction.
Care must be taken to ensure that when wall cladding,door frames etc are fixed cables are not damaged and metal structures made live.

Where a cable is concealed in a wall or partition at a depth of LESS than 50mm from any surface it must be enclosed in EARTHED metal conduit OR installed either horizontally within 150mm of the top of the wall or partition or vertically 150mm of the angle formed by the 2 walls or run horizontally or vertically to a accessory.

Regulation 522-06-06

If the cable is installed LESS than 50mm from the surface

be of a insulated concentric constructionIt must incorporate an earthed metaalic covering
or be of insulated concentric construction

Or be enclosed in EARTHED Metal Conduit or Metal Trunking ensuring they satisfy the requirements for a protective conductor..

No mention of capping!

I hope that clears that up

Best Regards

Tony

 

[NT]

Indoor or outdoor socket outlets that can be reasonably be expected to supply portable equipment outdoors MUST be protected by a 30MA rcd.Socket outlets installed out of doors must be of a weatherproof construction minimum IP54 and must ALWAYS be protected by a 30MA rcd

Not always, no. The above is true only for new installation work. There are plenty such sockets not RCDed and with no requirement to be so. Householders are often told they must upgrade wiring to meet new regs but in most cases this is not so.

Where a cable is concealed in a wall or partition at a depth of LESS than 50mm from any surface it must be enclosed in EARTHED metal conduit OR installed either horizontally within 150mm of the top of the wall or partition or vertically 150mm of the angle formed by the 2 walls or run horizontally or vertically to a accessory.

Regulation 522-06-06

If the cable is installed LESS than 50mm from the surface

be of a insulated concentric constructionIt must incorporate an earthed metaalic covering
or be of insulated concentric construction

Or be enclosed in EARTHED Metal Conduit or Metal Trunking ensuring they satisfy the requirements for a protective conductor..

No mention of capping!

... other than 'an earthed metallic covering.'


NT

 

[tony]

NT,

I would love to stay here and argue with you all day, as a fulled qualified approved electrician/ electrical engineer i wont.

Many electricians carry out sub standard work every day, what chance has a DIYER got, looking thru a readers digest book will give you a bit of advice, but you need to understand the regulations.

Connecting a cable from socket a to socket b will work, will it be safe, will it trip the overload device, was it safe to spur off that socket in the first place is your earthing and bonding up to scratch.

I looked at boiler for a friend of a friend the village spark(IDIOT) did not have the right material for the job(required 4 core butyl flex) he only had 3 core, and if you know what next yes he didnt bother connecting a earth to the boiler.

He was in the house 5 minutes and charged £33.

Clearly he didnt look at the job, other issues on the existing installation, and worse did not produce any electrical certificates.

Being a member of a governing body helps but is not a legal requirement, get a recomendation, ask to speak to previos customer/ quick email to them.

A good electrican will when looking around the electrical installation, say for a extra socket circuit.

Look at the existing overload protective devices.
Look at the earthing/bopnding
Take the cover off the consumer unit and test Ze

Maybe even do a quick pir


regards

tony

Even changing over your lounge light fitting, he should be issuing a certificate.

Anyway no more posts on this subject from me.

best regards

tony

 

[NT]

> Many electricians carry out sub standard work every day,

This is so true. I have a bad habit of asking domestic sparks a question to see if they can get it right, and the track record is overall not very good.


NT