Author Topic: UK electrical wiring  (Read 5388 times)

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Offline IanB

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Re: UK electrical wiring
« Reply #25 on: February 14, 2021, 12:55:31 am »
You certainly wouldn't see anything like that out here in earthquake territory. Looks like it would pose a far greater resistance to fire than the wood houses we have though. Seems like a really easy way to wire a home like that would be to run conduit from box to box and plaster over that.

Traditional homes in Britain were built as shown above with brick outer walls and "breeze block" inner walls and dividing walls. It gives the whole house a much more solid feel with better soundproofing. Newer homes are generally timber framed with brick outer facing to protect against the elements but wooden studded inner walls with plasterboard, because it is faster and cheaper to construct that way. However, if you build your own home and pay the builder to do it how you want it you can readily have an all-brick house.

I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate. Now if they had built the house in the first place with buried conduit, it would just be a matter of pulling new cable through in place of the old...

BTW, not many people have died from earthquakes in the UK. I think there has been maybe one casualty in the last few hundred years when a roof tile landed on his head.
 

Offline Monkeh

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Re: UK electrical wiring
« Reply #26 on: February 14, 2021, 12:59:29 am »
I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate.

Being that it's the normal method of construction here, it's quite normal to deal with chasing out the plaster and a little brick if needed. The other option is surface trunking, which is cheap, fast, and ugly, and how pretty much every council home will have been done.
 

Offline james_s

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Re: UK electrical wiring
« Reply #27 on: February 14, 2021, 01:09:20 am »
I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate. Now if they had built the house in the first place with buried conduit, it would just be a matter of pulling new cable through in place of the old...

BTW, not many people have died from earthquakes in the UK. I think there has been maybe one casualty in the last few hundred years when a roof tile landed on his head.

I've never heard of an earthquake in the UK, I haven't looked it up but I don't think it's very common at all there. Here on the West coast of the US they are a frequent occurrence though. Most are not of sufficient magnitude to be felt but every few years there's a small but noticeable tremor and usually every 30 years or so there's one large enough to cause some damage so it's a concern here. If not for that then brick and concrete would be very appealing for the reasons you mention.

Cutting channels in plaster could be accomplished in a few minutes with an appropriately configured router and filling them in would be no harder than patching the holes that are necessary for fishing new wires through existing studded walls. That sort of thing is never permissible here for line voltage wiring but I've done it a few times for low voltage network cables as there are much less stringent requirements for low voltage. Proper conduit is fantastic and a dream to work with but rarely seen in domestic environments except in garages and unfinished basements some jurisdictions require conduit for those areas where the wiring is otherwise exposed. If I were wiring a whole house from scratch though I'd be really tempted to do the whole thing with rigid galvanized conduit and the big spacious metal boxes with mud rings like they use in commercial buildings. My mother's house was owned by a commercial electrician and he wired the additions that way and it has been a real pleasure to work on compared to what I'm used to.
 

Offline iainwhite

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Re: UK electrical wiring
« Reply #28 on: February 14, 2021, 01:10:36 am »
I think my idea of skirting is not like yours.  Perhaps you can explain what that is. 

Skirting = Baseboard
 

Offline Monkeh

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Re: UK electrical wiring
« Reply #29 on: February 14, 2021, 01:14:40 am »
I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate. Now if they had built the house in the first place with buried conduit, it would just be a matter of pulling new cable through in place of the old...

BTW, not many people have died from earthquakes in the UK. I think there has been maybe one casualty in the last few hundred years when a roof tile landed on his head.

I've never heard of an earthquake in the UK, I haven't looked it up but I don't think it's very common at all there. Here on the West coast of the US they are a frequent occurrence though. Most are not of sufficient magnitude to be felt but every few years there's a small but noticeable tremor and usually every 30 years or so there's one large enough to cause some damage so it's a concern here. If not for that then brick and concrete would be very appealing for the reasons you mention.

There have been 25 recorded in the last 50 days. At least four of them felt. None sufficient to bother anything built properly.
 

Offline nctnico

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Re: UK electrical wiring
« Reply #30 on: February 14, 2021, 01:39:11 am »
I'm looking at rewiring my house because it's awful and there aren't enough sockets where they need to be.  I've been brushing up on my knowledge of the IET regs and am wondering why the bottom of walls is not a "safe zone" (to use 17th ed terminology).  I like the idea of having the wiring going through the skirting as I have heated flooring and, to me, it seems a much more logical place to route it all for increased adaptability and ease of access in the event of faults or additions than burying it in the wall.  (For reference all walls are brick, including internal.)
If the walls are brick then I'd cut slits in them to facilitate extra wiring (in conduit -but don't use the flexible stuff; pulling wires through it is horrible-). You can rent machines to cut these slits. Building some kind of trunking onto the walls is beyond ugly.
Brick!!!  Don't you guys add insulation at the inside face of the brick?  No framing?  No space to add insulation?  That is where wires are run in the US. 
Over here it depends a bit on the build style but typically there is an outer layer (can be brick, wood, whatever), and insulation layer and inner walls (can be concrete or brick). Wiring conduit is integrated in the walls. From what I've seen from British home improvement shows they don't build home much differently.

In the US the building style is completely different though.
« Last Edit: February 14, 2021, 01:43:20 am by nctnico »
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Offline gnuarm

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Re: UK electrical wiring
« Reply #31 on: February 14, 2021, 01:43:16 am »
I think my idea of skirting is not like yours.  Perhaps you can explain what that is. 

Skirting = Baseboard

Ok, in the US I don't know if it is prohibited, but we pretty much never run wiring in the base board (we do have baseboard heating elements though).  I think in the UK there are a lot more older buildings that need to be accommodated.  Here there's not much that wasn't built with studs even if it uses something other than dry wall for the surface. 

We just don't seem to have problems with this. 

Oh, I very seldom see anything inside a brick wall other than stud construction.  I have seen a few colonial era homes with the same brick inside that is outside.  Brrrr... no insulation at all.  That was a long time ago and I don't know how the ran wires.  Probably just avoided that wall. 
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Offline james_s

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Re: UK electrical wiring
« Reply #32 on: February 14, 2021, 02:50:26 am »
Surface raceways are relatively common here in some situations, I think they were especially popular in the 70s. They're a sort of conduit that consists of a backing plate that is screwed to the wall and then a rectangular cover that snaps on over it. It was used a lot for retrofit work, especially in commercial situations but I've seen it in homes too, especially in this situation where there's no stud space to run the wire through. Our cabin has some of the wiring done in raceways that are run along the exposed wooden beams.
 

Offline themadhippy

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Re: UK electrical wiring
« Reply #33 on: February 14, 2021, 03:03:37 am »
Quote
I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate. Now if they had built the house in the first place with buried conduit,
If your lucky 60's era house has metal oval conduit buried in the wall that you can pull your new cables into,using the old cables as a draw wire,so avoiding any chasing,even if there blocked  they make chasing the wall out easier as its only plaster you  need to remove
Quote
Cutting channels in plaster could be accomplished in a few minutes with an appropriately configured router
yes theres proper chasing tools,bit like a circular saw with  2 blades,but they are very  messy and need some form of vacuum attached unless you want to be cleaning up for hours days,however the easiest option is to give the apprentice a lump hammer and bolster chisel and tell em to get on with it,once you get the knack you can  chop a box and chase out pretty quick,unless its engineering brick.

 

Offline IanB

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Re: UK electrical wiring
« Reply #34 on: February 14, 2021, 03:37:52 am »
Being that it's the normal method of construction here, it's quite normal to deal with chasing out the plaster and a little brick if needed. The other option is surface trunking, which is cheap, fast, and ugly, and how pretty much every council home will have been done.

I think the plaster isn't deep enough, it's only a skim on the surface of the bricks. Surely to cut deep enough to bury wiring you need to chisel out the mortar between the bricks? I remember when my father was installing spurs he spent quite some time with a hammer and chisel doing that. And the original wiring was installed the same way. Obviously cutting out holes for the boxes involves even more chiseling. The apprentices when they were building houses in previous decades must have had plenty of work to do.
 

Offline Monkeh

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Re: UK electrical wiring
« Reply #35 on: February 14, 2021, 04:01:31 am »
Being that it's the normal method of construction here, it's quite normal to deal with chasing out the plaster and a little brick if needed. The other option is surface trunking, which is cheap, fast, and ugly, and how pretty much every council home will have been done.

I think the plaster isn't deep enough, it's only a skim on the surface of the bricks.

It's a lot thicker than you think it is. The base coat is usually up to half an inch thick.
 

Offline nfmax

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Re: UK electrical wiring
« Reply #36 on: February 14, 2021, 08:50:01 am »
I am rather curious about the best way to rewire a 1960's brick home, since cutting channels in the wall to bury the new cable seems to be too expensive/too much trouble for contractors to contemplate. Now if they had built the house in the first place with buried conduit, it would just be a matter of pulling new cable through in place of the old...

BTW, not many people have died from earthquakes in the UK. I think there has been maybe one casualty in the last few hundred years when a roof tile landed on his head.

I've never heard of an earthquake in the UK, I haven't looked it up but I don't think it's very common at all there. Here on the West coast of the US they are a frequent occurrence though. Most are not of sufficient magnitude to be felt but every few years there's a small but noticeable tremor and usually every 30 years or so there's one large enough to cause some damage so it's a concern here. If not for that then brick and concrete would be very appealing for the reasons you mention.

There have been 25 recorded in the last 50 days. At least four of them felt. None sufficient to bother anything built properly.

It's been almost 90 years since the last major earthquake  (Richter magnitude > 6) in the UK. The epicentre being out at sea, damage was limited. However, the Dogger Bank is now a major centre of offshore windfarm development.
 

Offline nctnico

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Re: UK electrical wiring
« Reply #37 on: February 14, 2021, 04:53:30 pm »
Being that it's the normal method of construction here, it's quite normal to deal with chasing out the plaster and a little brick if needed. The other option is surface trunking, which is cheap, fast, and ugly, and how pretty much every council home will have been done.

I think the plaster isn't deep enough, it's only a skim on the surface of the bricks. Surely to cut deep enough to bury wiring you need to chisel out the mortar between the bricks? I remember when my father was installing spurs he spent quite some time with a hammer and chisel doing that. And the original wiring was installed the same way. Obviously cutting out holes for the boxes involves even more chiseling. The apprentices when they were building houses in previous decades must have had plenty of work to do.
Nowadays you use a mill (*) for the conduit and round drill for the junction boxes. Don't chissel out the mortar; that is too narrow for the conduit to fit into anyway.

* something like this:

or this:
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Offline coppice

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Re: UK electrical wiring
« Reply #38 on: February 14, 2021, 05:03:22 pm »
Now if they had built the house in the first place with buried conduit, it would just be a matter of pulling new cable through in place of the old...
No it wouldn't. By the time the place needs rewiring usage patterns have changed, new bits and pieces altered from the original layout of the wiring, and the amount you can simply pull through the original conduits is limited. Conduit always sounds so flexible, but seldom really works out.
 

Offline IanB

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Re: UK electrical wiring
« Reply #39 on: February 14, 2021, 05:35:23 pm »
No it wouldn't. By the time the place needs rewiring usage patterns have changed, new bits and pieces altered from the original layout of the wiring, and the amount you can simply pull through the original conduits is limited. Conduit always sounds so flexible, but seldom really works out.

For instance, I grew up in a house that was built around 1960, and the builders only included one socket in each bedroom. I'm not sure how they ever thought that would be enough.
 

Offline coppice

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Re: UK electrical wiring
« Reply #40 on: February 14, 2021, 05:44:53 pm »
No it wouldn't. By the time the place needs rewiring usage patterns have changed, new bits and pieces altered from the original layout of the wiring, and the amount you can simply pull through the original conduits is limited. Conduit always sounds so flexible, but seldom really works out.
For instance, I grew up in a house that was built around 1960, and the builders only included one socket in each bedroom. I'm not sure how they ever thought that would be enough.
That was normal in 1960, and was considered perfectly adequate. By the mid 70s it was looking a bit weak, although even then if you suggested putting in lots of sockets many people complained that they didn't want their walls covered in sockets. The real problem with the one socket tended to be that they put it in the least useful spot in the room. :)
 

Offline james_s

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Re: UK electrical wiring
« Reply #41 on: February 14, 2021, 06:46:47 pm »
No it wouldn't. By the time the place needs rewiring usage patterns have changed, new bits and pieces altered from the original layout of the wiring, and the amount you can simply pull through the original conduits is limited. Conduit always sounds so flexible, but seldom really works out.

For instance, I grew up in a house that was built around 1960, and the builders only included one socket in each bedroom. I'm not sure how they ever thought that would be enough.

My aunt & uncle live in a house built in 1922 and originally when built there was only one duplex receptacle in many of the rooms, I think two in a couple of the larger rooms and this is a fancy enough place to have what was originally a maid's quarters in the basement. More were added sometime in the 1950s judging by the wire used, and then they added more in the 80s and 90s. Used to be people didn't have much that needed to be plugged in. A family might have a radio, a vacuum cleaner, a clothes iron, maybe a few lamps. For whatever reason ceiling lights went out of fashion in 1950s-60s America and lamps became very popular and people also started owning a lot more electrical gadgets in the post-WWII boom years.

I find there are never enough receptacles even in modern houses and there is never one quite where you need one. I would love to have them every 4' on every wall in the house, and a double gang box with a pair of duplex receptacles is preferable to a single one just about anywhere, you can never have too many places to plug something in. At this point I have 6-way adapters and power strips all over the house, the total load is not high but there are a lot of things plugged in.
 

Offline Cerebus

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Re: UK electrical wiring
« Reply #42 on: February 15, 2021, 03:21:21 am »
You certainly wouldn't see anything like that out here in earthquake territory. Looks like it would pose a far greater resistance to fire than the wood houses we have though. Seems like a really easy way to wire a home like that would be to run conduit from box to box and plaster over that.

That's exactly what is done for a plastered brick wall, except it's not conduit per se. You chase out a channel with one of these:



Then you put "twin and earth":



aka '6242Y' into the channel, cover it with PVC capping:



nailing the edges into the wall, and finally plaster over the top.

The OP ought to acquaint himself with the Building Regulations part 'P' before embarking on any DIY re-wiring and should be aware that most work of any significance will have to be inspected by either a 'registered competent person' or a building control officer.

A note for the non-brits reading this: There is not a statutory code for electrical wiring in the UK in the same sense there is in other places. There is the IET wiring regulations, which are misleadingly named, they are not government regulations, merely guidelines issued by the IET. The actual government regulations are quite short and sweet, and basically boil down to electrical installations must be safe and not present a risk of fire or electrical shock. Following the IET guidelines is generally regarded by the various bits of government as an indication that the real regulations have been met, but it does not, and never has, definitively indicated that an installation meets the statutory standards - it is quite possible to 'do it the way the book says' and produce an unsafe installation in some circumstances. An indication of this is the boilerplate wording from the Health and Safety Executive that you'll find prefixing every issue of the IET Wiring 'Regulations' in recent years, vis:
Quote from: Note by the Health and Safety Executive
Installations which conform to the standards laid down in [this standard] are regarded by HSE as likely to achieve conformity with the relevant parts of  [the legislation].
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline MajorbobTopic starter

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Re: UK electrical wiring
« Reply #43 on: February 16, 2021, 09:28:52 pm »
In this greatly informative discussion I have started looking into Part P, I spend every day modifying wiring in machines where "along that random bit of framework is fine, just cable tie a bit of conduit until you have time to fix it properly" is an unfortunately common occurrence (and often takes a long time until it is fixed properly).  I have had some exposure to the 17th (and 18th) editions but the course is for the facilities team, which isn't me.

I have now given up on the idea of running behind skirtings, as laying metal conduit or running SWA just isn't really going to be feasible... especially once it's run up to sockets... I don't need my house looking like a machine cell at work!

Thankyou all for good discussion and aiding my understanding, planning for the rewire can now continue!
 


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