Buying house - rewiring query

[izools]

I have the opportunity to buy a property built in 1965 for a very good price.

The internals / decor are all original but at least it's all been given uPVC double glazing and re-clad in PVC recently (is a concrete crosswall construction, the front was originally timber clad).

I'm comfortable with the fact there will need to be completely new decor throughout and a new kitchen and bathroom to boot but I'm wondering about the wiring.

The supply to the property is 60A. I would be asking the local energy board to upgrade this to an 80 or 100A supply and provide an isolator switch.

Now, all the wiring is T&E PVC as far as I can tell but it is original. I would say it is imperial gauge given it was installed in 1965. There are three circuits - a 5A lighting circuit, a 30A ring main, and a 30A cooker feed.

The cooker circuit appears to have been installed at a later date as a 30A fuse wire has been placed in a 15A carrier and a 6MM cable fed from the CSU to the cooker, with (the imperial equiv of) 2.5MM T&E disconnected and cut back in the CSU.

I won't be using this as there's a gas feed to the property.

My guess is the 15A circuit was used for the now removed central air heating system that was installed under the stairs with vents feeding hot air around the property.

Now - how much of this is likely to need to be removed? I'm not an electrician myself and would never profess to be but I'm not ignorant of certain things either.

I would like to think I can get away with replacing the CSU, providing equipotential bonding where necessary, and replacing the fixtures (ceilling roses, pendants, switches, sockets, etc) with modern brushed steel equivalents.

I would however look to get a second ring main added for the kitchen due to all the high load appliances in there. I'll be getting a new kitchen fitted anyway so a bit of mess is fine.

I can't see any scorching or discoloration on the current PVC wiring but will have a look in more depth at some point.

So what do you all think? Should I budget for a full rewire when considering my offer to the estate agents? I'm really adverse to ripping the PVC wiring out and replacing it if it's good...

 

[martinxxxxxx]

I think it must be worth getting a EICR full electrical inspection done. Ask the electrician to look in the loft and lift some floor boards and inspect all of the accessible sockets. Ask him how long it will take. Discard any that say it can be done in a couple of hours.
Without do this, no on e can really say whether you need any rewiring, but it is defo worth finding out now rather than down the line when you have painted everywher and made it you own

 

[ban-all-sheds]

Even if none of the wiring already there needs to be replaced, you may find that you want a lot of additions and changes, and if (as I get the feeling you can) you can have work done before you move in, i.e. before you've got carpets, curtains, furniture, people and clothes in there, before you've papered and painted etc, there will never be a better time to have it done.

You're planning a new kitchen and bathroom, and full redecoration anyway.

Not having to clean up each day, not having to keep some power on, not having to move furniture, not having to replace floorboards all the time, not having to worry about the mess from using power tools on walls... all these things will make an electrician's job quicker, and therefore cheaper.

Think hard about where to have sockets - it's difficult to have too many, and also about what circuits to have. The items on the list below won't all apply to you, but they are worth thinking about:

• Upstairs sockets
• Downstairs sockets (or a L/R or front/rear split)
• Kitchen sockets
• Circuit for appliances
• Cooker circuit
• Non-RCD circuit for F/F
• Non-RCD circuit for CH boiler
• Dedicated circuit for hifi
• Dedicated circuit for IT equipment
• Upstairs lights
• Downstairs lights
• Lighting circuits with switches in the usual places but with 2A/5A round pin sockets at low level.
• Immersion heater
• Loft lights
• Shower
• Bathroom circuit
• Alarms
• Supply for outside lights
• Supply for garden electrics
• Supply for shed/garage

Plus any peculiarities brought about by your house layout & construction - e.g. in mine because of solid floors and where the socket circuits run, I have a radial just for a socket in the hall, the doorbell and the porch lights.

Unless you want to go to the expense of RCBOs throughout, the CU should have at least 3 sections, 2 on RCDs and one not into which you can install a mix of RCBOs and MCBs.

It can be a good idea to put all wiring in conduit for ease of future changes. And if you specify metal conduit for switch drops, or BS 8436 cable it removes the need to have RCDs on lighting circuits (apart from bathrooms).

If you live somewhere where supplies are dodgy in the winter, have the lights, the boiler supply, and a socket in each room wired to a separate CU, or a separate section in a large one, that can be supplied by an emergency generator - lights, heating, TV and a kettle/microwave make life a lot more bearable.

Flood-wiring with Cat6 or Cat6a cable is worth thinking about.

 

[izools]

Thanks guys that's given me a lot to think about, great help. Cheers

 

[Taylortwocities]

I would like to think I can get away with replacing the CSU, providing equipotential bonding where necessary, and replacing the fixtures (ceilling roses, pendants, switches, sockets, etc) with modern brushed steel equivalents.

If you use metal lights/switches the lighting circuit must be earthed. If it were installed in 1965 I would bet that the lights are not earthed so you'll need to rewire the lighting throughtout, unless you want to be stuck with plastic fittings.

Per the above I'd budget for a rewire & new CU. It would be false economy not to do it before the place gets full of furniture, laminate flooring and people.

 

[izools]

I would like to think I can get away with replacing the CSU, providing equipotential bonding where necessary, and replacing the fixtures (ceilling roses, pendants, switches, sockets, etc) with modern brushed steel equivalents.

If you use metal lights/switches the lighting circuit must be earthed. If it were installed in 1965 I would bet that the lights are not earthed so you'll need to rewire the lighting throughtout, unless you want to be stuck with plastic fittings.

Per the above I'd budget for a rewire & new CU. It would be false economy not to do it before the place gets full of furniture, laminate flooring and people.

We'll see.

If the existing lighting and ring main is undamaged and 16th ed T&E of the correct gauge then I see no reasonable point replacing it.

Of course if it's twin no earth as you suggest then absolutely, rip out and replace

 

[Spark123]

Even if it is 2.5mm equivalent if it is original it is 47 years old so isn't really worth messing around with, a full rewire with the place empty is probably the best way to go - then you can specify what you want.
(ought to be to the 17th ed too)

 

[RF Lighting]

Remember old 2.5mm² t&e may have an undersized CPC.

I'd always recommend a rewire in this situation.

You have no idea of what condition the existing wiring is in, what additions / alterations have been done, or who has done them. They may well be hidden joints too which are going to be a huge PITA if they ever go wrong. Even a full inspection could miss some bodge done by the previous owners.

Cut the whole lot off and start again. It'll be quicker and cheaper than trying to modify the old wiring to modern requirements, and you're left with peace of mind of an installation that you know will be good for the next 50+ years.

 

[Adam_151]

Remember old 2.5mm² t&e may have an undersized CPC.

While I don't dispute the fact that a re-wire is really needed here..

2.5/1 is only normally an issue on 3036 fuse or LM breaker, etc. with 60898s unless your PFC is sky high not normally an issue.

From mid 60s its likely to be 7/029 with 3/036 cpc rather than 2.5/1 although additions may be in 2.5/1.

I wouldn't hesitate to recommend re-wire in situation described though, not sure I could justify 2.5/1 cable as a reason though

 

[PrenticeBoyofDerry]

izools, you need an EICR doing, that will determine what condition the installation is in and whether all or any circuits are safe for continued service. Also remember that even though you are doing away with the electric oven/cooker and having gas, you will require electric supply for gas ignition and maybe any hob extraction that will be required, so the cooker circuit could still come in useful, if safe to use.

 

[flameport]

An EICR on a property that old will be a waste of time and money.

Even if the wiring is perfect, there won't be anywhere near enough socket outlets (1 per bedroom was typical then, with perhaps 2 in the other rooms).
Bedroom lights will probably be offset towards the windows, and all the other stuff which didn't exist in 1965 obviously won't be there either.

A 60A supply is more than adequate for most houses - unless you will be installing silly things like electric showers or electric hobs.

re-clad in PVC recently (is a concrete crosswall construction, the front was originally timber clad).

That may well be the reason why this particular property is available for a low price.
It could also make rewiring and other tasks far more difficult and expensive.