rewiring house

Feb 28, 2016 29 Replies

good morning



i am about to undertake rewiring my 1930's edwardian semi as i am on a very limited budget. i intend to contract an appropriately qualified electrician to make cu connections, testing and sign off.



it is some years since i did my last rewire and so i am looking for some guidance on cable specification, methods of chasing / protecting cables in walls, fixing through stud walls / floor joists etc.



i intend to have several circuits:



kitchen ring cooker ground floor sockets ring first floor sockets ring attic sockets ring freezer / alarm circuit ground floor lights first floor lights attic lights bathroom heat matt circuit (3 locations) electric shower outdoor garage / workshop ring



am i right in thinking normal sockets is 2.5mm twin and earth? lighting is 1.5mm twin and earth?



and what capping do i need to cover cables chased in the wall - i think it's metal and does it have to be 50mm deep?



any help will be gratefully received.



many thanks.


Good luck in finding one who will do that. They can sign for Inspection and Testing, but not the Construction. If they do, they could be chucked out of their governing body. I know people do it. Why, is beyond me, if there was an accident/ fire, then they would be in deep trouble.

You can put in a Building Notice to the Council, then get a 3rd Party Inspector to check it. That'd be £400ish I reckon.

....

For a ring, 2.5 is OK, why not a 4mm radial?

1mm is fine for lighting.

None

No, 1mm deep is enough. 50mm was/is the depth that did not need RCD protection, but any socket outlets, anything in a bathroom and other things need RCD protection now, so there is no point in putting cables so deep.

ntend to contract an appropriately qualified electrician to make cu connections, testing and sign off.

ation, methods of chasing / protecting cables in walls, fixing through stud walls / floor joists etc.

I think you need to do your own research, in detail. You can't expect anyone here to give you a full, foolproof, comprehensive guide to house wiring.Your problem isn't the questions you ask; it's the questions you don't realise you need to ask.

Bill

Get up to date on main bonding, equipotential bonding, RCD requirements, split load CUs, outdoor electrics and cables buried in insulation.

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NT

If you're doing the entire house you can chuck everything away and make an entire new installation and make a design from the regs instead of working out how to modify what you've got to make it fit the regs.

Conceptionally, just start from a masonry box with a 100A supply head, ignore absolutely everything that's already there.

jgh

Yes - that's what I did. Although I have my own Megger, so they're letting me sign off my own work.

Although 1.5mm2 does have the advantage of being a little bit tougher - and buys a fair bit of flexibility in terms of max lengths of circuits.

I found it very useful to use 20mm oval conduit - wall chases are hardly any deeper and it both protects the cable from being damaged by the plastering trowel - and you can replace a cable easily.

Run some cat5 everywhere while you're at it. It's cheap and you will regret it later if you don't.

If it still has 1930s fittings, auction them or feed them 12v via the original fusebox.

NT

Even in the days when I helped rewire this 1930s house the cables were no in anything in the walls, unless of course it was easy to do it. I've never had any issues from this approach over the years. Of course I know where they are! The one thing I'd suggest is that a proper record of where wires run is made when its done. its not in any regulations but after you snuff it and assuming the building is not demolished to build affordable rabbit hutches, then the next occupant would like this a lot. The old wiring was a nightmare being mostly in metal conduit but the bodgers had been very active over the years and it happened more than once than life cables appeared many feet away from one might have expected them for wall lights long removed etc.

Brian

In message , Brian Gaff writes

Photos are good for this.

I'd be certain I could find such a person before starting..

Very very little of the basics have changed in this time.

TLC sell a site guide to the latest IEE regs

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It's been said that house wiring is 95% general building skills and only

5% electrical. In terms of the effort involved.

True.

That is probably about right for a basic rewire.

The ability to second fix a socket or switch in college and get full marks is of no use if you cannot get the cables correctly installed up to the socket or a switch in a house when at work.

And place some spare conduits, ready for future use. I put four spare ones going from under the ground floor, up to the first floor, two of which have since been used.

SteveW

I recall electrician's guides to the IEE regs in the late 70's. There's certainly more detail[1] to worry about now, but the core is the same (after all, physics of cables doesn't change).

[1] bonding has changed a lot, RCDs and the fact that I tend to actually check voltage drops, cable vs breaker disconnection times and the capacity of the cable vs installation method if insulation is involved. Back then, folk seemed happier just slinging in cables of standard sizes without worrying too much. But back then, we did not have 12" insulation over the cables and to be honest, a typical domestic property it's hard to get the other factors wrong.
+1 from me. "Wiring" is easy, when you do it on a sheet of ply in the open at chest height in an instructor's training centre.

Routing the cables in a real house is a PITA compared to the actual connecting and testing.

Houses should be built with mini risers...

I think the section on lighting needs redoing. It looks like it was written a couple of years ago; LEDs have come on leaps and bounds since then. (For example, LED downlighters are no longer ridiculously expensive, and offer reasonable colour - and obviously much better efficiency than halogen.)

It's a wiki - type away:-)

I would start with "CFLs are s*it"

En el artículo , ARW escribió:

Good man. Hateful things.

Now that LEDs finally are becoming usable, I can get shut of my collection of incandescents :)

I am nearly all LED. Internally my house is all LED.

Now is the time to convert the gf....

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