# When to rewire house?



## gasmansteve (28 Jun 2008)

Hi folks
My daughter and hubby have moved into their `new` house today and the estate agent in the sales blurb suggested it might need rewiring . It was built in 1969 and does have oldish looking sockets. An electrician friend of mine (thats a train electrician, he repairs trains) suggested looking at the wiring and checking the general condition as possibly the lighting circuit may not have an earth. My own house is a similar age and but for changing the sockets the wiring is fine. I would ask an electrician to check but after problems another friend of mine had with a spark who said all sorts needed doing costing a packet none of which needed doing in the end.Is there anything specific apart from the lighting earth to look for? I want to save them some expense if poss but if it needs doing fair enough I wondered what can actually wear out? 
Cheers
Steve
Ps I understand the previous occupant was an old electrician


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## oddsocks (28 Jun 2008)

Steve, i'm not an electrician, but in a recent conversation with a friend who is one, he said the recommended rewire at 20 (or 25 years -can't remember) was because that was the guaranteed life of the PVC coating for the twin and earth cable. Bit like a 'use by' date! 
so a 1969 house is 39 years old and worth at least checking.  Again from memory a safety test was about £80 (but often ends up in condemnation due reg changes since 1969) - just think of the number of appliances, ceiling lights. power showers, elect showers etc that didn't really exist in 1969 

Dave


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## Karl (28 Jun 2008)

Why not get a few sparkies round, and see if there is a common opinion on what needs doing.

My in-laws bought their current house 15 years ago. They were told when they bought it that it needed re-wiring. They decided to just change the sockets......

Earlier this year they had the whole house re-wired. It was only then that we found out that my MIL had been chaning the fuse wire on the ring fuses weekly, as they kept on blowing. This had been going on for "a few years".

The sparkie said wiring (which was the old rubber coated wire, rather than the PVC you get now) was in a terrible state, and there were breaks all over the place.

Cheers

Karl


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## OLD (28 Jun 2008)

A modern installation is properly earthed and protected with rcd and 'fused' with mcb,s extra protection by materials and positioning is provided in wet areas this all adds up to a higher level of safety for the user.


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## wizer (28 Jun 2008)

My house was built in the 30's and was probably rewired in the late 70's. When we moved in we pulled the place apart doing all sorts of renovation work while it was empty. I wished we'd had it re-wired. The amount of time and money I have spent fixing 'bodges' would have justified a full re-wire.


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## RogerS (28 Jun 2008)

Any electrician that you invite round will tell you that it doesn't meet current regulations and so will need rewiring. 

The key questions really for you are (a) is it dangerous (from an electrical shock perspective) and (b) is there a fire risk due to a high resistance joint somewhere, cables being overloaded etc.

From a pragmatic point of view, before that bloody Part P rubbish came along, I would have replaced the consumer unit myself with a new one to 17th edition spec. That would mean that (a) I was protected from electrical shock as far as was reasonably practical and (b) if the cabling was dodgy then I'd get a lot of nuisance tripping of the RCD...which in a way answers your original post..ie rewire needed.

Unfortunately I doubt if you will find an electrician willing to just replace the CU as IIRC that is classed as a major change which then necessitates him carrying out a full inspect etc etc in order to give you a certificate. But if you're not moving for a while then that's probably not an issue.

Alternatively you could ask for a full inspection (which is probably a days work). That will empirically measure the insulation resistance etc of your cables etc.

As far as the earth cable and the lighting circuits are concerned, it is only of importance if you have any metal lights that require earthing. If you don't have any metal lights then don't worry about the earth missing.

Rewiring is a huge upheaval unless you are happy to have the cables fixed on the surface of the walls and ceilings. This usually does not guarantee a harmonious marital arrangement.

BTW 17th edition of the regs raises more questions than answers


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## gatesmr2 (28 Jun 2008)

Ok now you got me thinking :shock: 

So if the pvc cover is only meant to last 25 years on wires where does that leave you on insurance for your home.
I assume you have to keep your house in a good state of repair etc etc and if 25 years is the limit what happens if you do have a fire caused by old electrics, does the insurance company have a get out clause :? 

My house which i've been in for 30 years seems ok no tripping at the fuse box but i'm guessing the wiring is getting on for 40 plus years old so just thought i'd see if anyone knew or has experienced this could be problem.


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## Jake (28 Jun 2008)

PVC is fine - they haven't had any age related failure problems AFAIK.

If the cable is rubber insulated (or worse,aluminium cored) definitely re-wire. 

Otherwise, try to find a sensible electrician who isn't of the 'must rewire everything' type.

They always say 'needs a rewire' on surveys - it's a back-covering standard clause.


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## Woody Alan (28 Jun 2008)

It depends on how you view the situation.
My house built in 1964 doesn't have earthed lighting. I have no need to touch the lights unless a bulb goes, so turning of the fuse makes it a safe operation. I fitted an mcb split board prior to part P nonesense. All my kktchen socket are on the trip apart from fridge and freezer. You have to balance a risk factor against scaremongering, I don't know what the statistics for injury due to no earth on lights are but it has to be small. The chances of a well fitted light fitting going "live" due to a fault is pretty slim.
I just add earths as the opportunity arises if the floor is up.
The other thing to bear in mind is if the fitting should go "live" and you happen to touch it as long as it is on a 25mA RCD you won't get electrocuted as the imbalance you create will throw the trip, just like the outdoor type protection.
As for the PVC degrading as long as it hasn't been subject to UV light or certain products that cause it to turn jelly like (some plasters) then it isn't going to be a problem. Bear in mind there are many industrial installations where single insulated (unlike your double) cable has laid in metal trunking with other cable for 50years and shows no sign of degrading.
Upgrading the consumer unit to full protection, is a very good idea but if a sparky does it he probably under part P has to bring all the earthing up to spec, as part of his sign off. but I don't see the need for replacing all the wiring. 
Alan


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## Anonymous (28 Jun 2008)

I have been a qualified electrcian and electronics technician for around 25 years (before I took my degree and became an electrical design engineer), and I would recommend rewiring the house.

I have seen many properties of this age with significant degredation of the insulation on cables. Materials have a finite life.


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## Tusses (28 Jun 2008)

do you have to be 'certified' or just 'competent' to do your own wiring - ie not for anyone else.

Last time I checked - you could do your own gas work too :shock: If you were 'compepent' - no need for gorgi - but that was before the new rules came in and things needed to be signed off.

I have rewired several houses in the past, and moved the odd cooker gas point too. Now it seems like a lot of effort to fugure out what you can and cant do. 

The short answer is always 'you cant do any of it' but I am sure you can change sockets as long as they are not in the Kitchen Bathroom or and outside work.

I really must read up on it, as our house needs rewiring and I cant see me paying for someone else to do it :evil:


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## Jake (28 Jun 2008)

Tony":1pncjfzk said:


> I have been a qualified electrcian and electronics technician for around 25 years (before I took my degree and became an electrical design engineer), and I would recommend rewiring the house.
> 
> I have seen many properties of this age with significant degredation of the insulation on cables. Materials have a finite life.



So you think that every house which dates back further than the mid-eighties (which hasn't yet been rewired) needs a full rewire?

You should have been a surveyor!

(edit, sorry,I only saw the 25 years comment, not the '69 date. Still, if it's PVC, I'd get it tested rather than assume the wiring needs replacement. The accessories probably need replacing, and it's likely that they'll want more sockets anyway)


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## RogerS (28 Jun 2008)

Tusses":aiaizpvf said:


> do you have to be 'certified' or just 'competent' to do your own wiring - ie not for anyone else.
> 
> Last time I checked - you could do your own gas work too :shock: If you were 'compepent' - no need for gorgi - but that was before the new rules came in and things needed to be signed off.
> 
> ...



Short answer to a very long question.....if you are intending to rewire yourself then you can do it yourself but it is notifiable under Part P...notifiable to either Building Control (who will make a charge) or you get in a sparkie and pay them to do it. Highly unlikely you'll find a sparky who will come in and test/inspect your own work without having seen the actual cable runs going in.


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## skipdiver (28 Jun 2008)

You can't seem to find two electricians who agree on the current regs.Most sparky's i know say it is a total waste of space but they are obliged to do unecessary work when doing jobs if they discover something that is now deemed not safe.When i renovated my last house,i asked a sparky at work about exponential bonding in the bathroom and his answer was "dont bother.i haven't in my house"He went on to say that he had yet to see a convincing argument that all this bonding was needed and that it would actually do any good anyway.

When you have a sparky of many years,who runs his own business telling you this,then what chance has a layman like me got.I moved into my house last month and i know there are issues with the electrics.Some of the upstairs ones dont work at all and i am having to get my new workshop wired at some point.If i call a sparky in to quote for the work,will i be told that i have to have a load of extra work done at huge expense?

Tusses.I remember getting into a discussion on another site about what you are and are not allowed to do yourself regarding wiring.Several sparks gave such conflicting advice that the discussion descended ino argument and namecalling.It got fairly nasty at the end and no-one seemed to be any the wiser.


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## dennis (28 Jun 2008)

Steve

One thing to check is if the cables are run through plastic conduits as then it is just a case of pulling the old wiring out and pulling the new ones through behind them without all the disruption of cutting chases and replastering,unless you are adding or moving sockets etc.

Dennis


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## Woody Alan (28 Jun 2008)

It is quite simple  he says setting of an argument. You are allowed to do all of your own wiring as long as you consider yourself competent.

The real question is what wiring is notifiable for building regs part P. The stuff that is notifiable can be signed of by a part P sparky or the council if you put in a request prior to work.
Notifiable includes kitchen/bathroom/outside/change fuseboard/install new ring main. What isn't, is fixing a fault or adding the odd socket (exc bathroom etc).
This is it in essence without going into fine detail. B&Q have some big boards up in their electrical dept dispelling some myths.

Alan


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## skipdiver (28 Jun 2008)

I know i can change sockets and repair stuff.My wiring seems quite good on the face of it.Definitely been rewired in recent years but by whom,and to what standard?Will a new sparky come in,start quoting part P and wanting to rip out all my wiring.It seems to be a minefield and i'm sure some sparks are using it to generate work


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## dennis (28 Jun 2008)

Steve

I agree that some sparks will use it to generate work but this happens in all walks of life, it is a case of finding someone trustworthy and not out to rip you off.

Dennis


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## Woody Alan (28 Jun 2008)

> i'm sure some sparks are using it to generate work



Maybe, but a friend of mine who is part P sparky, is sick of going round to price a simple job and then faced with "having" to tell the customer his earth will have to be upgraded as part of the job and so adding cost to the job. The result is a customer like yourself perhaps, doubts the sparky's integrity and or decides they don't need the original job done after all, so wasting his time.

Alan


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## dennis (28 Jun 2008)

Alan

It all really boils down to honesty and trust,if the sparks is honest about the work that is needed and the customer does not believe him and gets someone elses opinion surely if they are honest the customer will be told the same.

Dennis


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## skipdiver (28 Jun 2008)

Yes i agree with what you say Alan.Obviously i know regs have to be followed and i think the earth bonding thing happens all the time but for your average punter it's a minefield.Even the sparks i come across at work don't agree on interpretations of part P.

I have someone coming round once i get the roof on my workshop,so will see what happens.

I have a sparks in the family but he's married to my niece and they're not my favourite people.


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## Digit (28 Jun 2008)

I haven't personally seen PVC wiring deteriorate other than where a faulty socket has caused overheating.
With the passage of time loosening of the clamp screws appears to be the major cause of problems.
As regards running PVC cables in conduit I would point out that PVC when damp produces hydrochoric? acid.
That mistake cost a number RAF pilots their lives!

Roy.


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## dennis (28 Jun 2008)

Roy

I have seen lots of pvc cable run in both plastic and metal conduit,I rewired my own house about 18 years ago and an electrician advised me to use plastic conduit,are you saying that this is wrong.

Dennis


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## gasmansteve (28 Jun 2008)

Thanks all for the very helpful replies.
It looks like `When to rewire a house` raises more questions than answers!.
My own industry (Gas) has just as many if`s, why`s and maybe`s as the electrical and even now you can have the situation where two qualified gas engineers can arrive at different decisions :shock: . Only the other day someone told me about a well known and respected gas company condemning one of their own earlier installations !!. I`m afraid when it gets to the point that a qualified and renowned firm starts condemning itself it does`nt bode well for the unqualified amongst us. Today I have spoken to six people down my daughters street none of whom have rewired but just replaced the sockets/switches and after checking her installation myself I am happy to do the same. No doubt someone could justify a rewire after ten years quoting `What if` but I think common sense must prevail. A thought occurred to me:
We are constantly told what disgraceful and wasteful beings we are using supermarket carrier bags, and plastic containers which lie dormant in landfill for hundreds of years because they DON`T degrade so WTH does happen to plastic ? does it degrade or not it can`t do both??
Cheers
Steve
Ps I know its not carrying electricity but you get my drift :wink:


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## Digit (28 Jun 2008)

No! In metal conduit. PVC moulding tools are normally chromed because of the corrosion problem.

Roy.


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## dennis (28 Jun 2008)

Steve

I had a prime example of this several years ago with gas fitters.I did a gas board fitter a favour so he said that if I needed any gas fitting doing he would do it cheap,sometime later I was buying a new canon caress gas fire from the gas board showroom, and he fit it as a favour anyway not long after it kept going out so I rang him and he told me that he had found out that there was a design fault with this fire and that if I rang the gas board they would send a fitter and as soon as he saw the fire he would know that it needed a replacement part with a hole at a slightly different angle.Well I got home one night to find a fitter had been checking the fire for 2hr and he told me that there was not enough gas pressure,so I told him that I was told there was a design fault with this fire to which he said was rubbish and that I needed all the pipework renewing and left.I rang the guy who fit it and he said that the other guy was talking rubbish and that he would sort it and a few days later another fitter came and changed the faulty part in about 10mins and it is still working well.

Dennis


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## Woody Alan (28 Jun 2008)

> because they DON`T degrade so WTH does happen to plastic ? does it degrade or not it can`t do both??


well it depends on the molecular bond/chain that is used in manufacture, but I can tell you for an absolute fact if you hang on to a modern flimsy shopping bag for 6 months it will turn to dust when you try to pick it up. Proved it to my daughter the other day who at school is still having this mis information spouted at her regularly. I probably have a few more ready to fall apart in the workshop now tucked away with a few bits an bobs in...they don't even have to be in UV sunlight. It's one more bit of mis/dis info that is propogated. Other plastics may differ of course.
Alan


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## Rich (28 Jun 2008)

I'm told by the sparky at work that after July the first all new socket outlets fitted will have to be of the integrally fitted RCD type, this is going to be costly, this complies with the 17th edition, he said. :shock:


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## Digit (28 Jun 2008)

Not so Rich the Regs state that all circuits must be protected, that includes lighting.
At least that's how I read them.



> Additionally, all socket outlets rated at 20A or below within a domestic building will require 30mA RCD protection*. This means that all ring main circuits from consumer units will either need to be fed from the RCD side of a traditional split load board or have individual residual current breakers with overload (RCBO) ways.



Roy.


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## Jake (29 Jun 2008)

Woody Alan":3ovt6lhn said:


> I can tell you for an absolute fact if you hang on to a modern flimsy shopping bag for 6 months it will turn to dust when you try to pick it up. Proved it to my daughter the other day who at school is still having this mis information spouted at her regularly.



Which shop was it from?


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## Rich (29 Jun 2008)

I may have to eat humble pie here, I'll return to this on Monday when I will ask him about this, he has just passed his 17th edition test, my manager also echoed the same about RCD socket outlets.


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## gasmansteve (29 Jun 2008)

Dennis
I sympathise with both the fitters who were probably doing what they thought was right given the available info to them by their bosses (don`t get me started on that either :x ) Do you know as a gas transporter who I work for we presently have to provide (at present) 21mb +/ - 2mb so 19mb or 23 mb is supposed to be acceptable at the meter BUT some boilers lock out less than 20mb so whats the score there?? One hand not knowing what the other is doing methinks!.

Alan
Yes thats what we are up against, though not sure how I can check the molecular bond/chain of my daughters wiring but I`ll give it a go, just have to dig out the old mass spectrometer and electron microscope out of the shed :lol: .

Rich
Are you like me sick and tired of being told what to do with your house/car/job/household waste etc etc to satisy some jobsworth in an office trying to justify his job? AAArgh must lay off the red meat :x


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## gasmansteve (29 Jun 2008)

Jake":7ubl8vkp said:


> Woody Alan":7ubl8vkp said:
> 
> 
> > I can tell you for an absolute fact if you hang on to a modern flimsy shopping bag for 6 months it will turn to dust when you try to pick it up. Proved it to my daughter the other day who at school is still having this mis information spouted at her regularly.
> ...



:lol: :lol: :lol:


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## Digit (29 Jun 2008)

> Are you like me sick and tired of being told what to do with your house/car/job/household waste etc etc to satisy some jobsworth in an office trying to justify his job?



Who isn't?

Roy.


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## Rich (29 Jun 2008)

Steve, I'd really like to answer you on this one, but I dare'nt, I've been censored too many times for speaking my mind, having said that, have you noticed how quiet the forum is without a bit of contemporary chat about everyday life, but I do agree with your comments and my answer is YES, YES YES!!!.

BTW Have you seen the price of red meat? I have'nt had a sirlion steak for weeks now, even rump is a crazy price, bacon chops are the highlight of my week at present.

Rich.


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## Anonymous (29 Jun 2008)

Rich":29u2payt said:


> Steve, I'd really like to answer you on this one, but I dare'nt..............
> 
> my answer is YES, YES YES!!!.
> 
> Rich.


 :? 




:lol: :lol: :lol:


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## RogerS (29 Jun 2008)

Rich":1sxv8sjj said:


> I may have to eat humble pie here, I'll return to this on Monday when I will ask him about this, he has just passed his 17th edition test, my manager also echoed the same about RCD socket outlets.



I think he may have been interpreting the rules and deciding for himself that they are referring to installing a new socket as a spur on an existing unprotected ringmain...or else he's talking rubbish and misinterpreting the rules.


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## Jake (29 Jun 2008)

gasmansteve":2efwunmv said:


> Jake":2efwunmv said:
> 
> 
> > Woody Alan":2efwunmv said:
> ...



Was it Tesco or Asda, perhaps?


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## Woody Alan (29 Jun 2008)

Jake wanted to know


> Was it Tesco or Asda, perhaps?



I have no particular alligence  I have had bags from both that do it, I presume that's what they are now designed to do.
EDIT http://www.guardian.co.uk/environment/2 ... 7/waste.g2

Alan


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## dennis (29 Jun 2008)

I am just looking at a co-op shopping bag and it says,from the date of manufacture,the plastic will start to degrade in approx.18 months time.The whole process will take about 3 years.See bottom of bag for date of manufacture.

Dennis


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## Jake (29 Jun 2008)

I think it's only Tesco, Asda and the Co-op as yet, but I may be out of date on that.


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## Anonymous (29 Jun 2008)

Jake":18o5s03h said:


> (edit, sorry,I only saw the 25 years comment, not the '69 date. Still, if it's PVC, I'd get it tested rather than assume the wiring needs replacement. The accessories probably need replacing, and it's likely that they'll want more sockets anyway)




Testing wiring won't really tell you the full story. It may test OK for insulation resistance (the area where wiring generally fails), but it won't tell you how brittle the wiring is unless the person inspecting actually uncovers sections and looks at it. I have seen many installations where the insulation just cracked and fell away with slight manual bending of the wiring; a fire risk. 

I was once asked to do someone a favour and look at a house where fuses kept blowing. The reason was that someone had walked in the loft, trodden on a piece of cable, and the thing simply crumbled and shorted. Took ages to find!

I have to say that one thing I am fed up of seeing on this forum (not aimed at you Jake) is people with no qualifications and little knowledge advising others, often very badly, about matters of safety. 

Personally, rather than asking a forum of amateur woodworkers whether I should have a house rewired or not, I would get an electrical engineer (not an electrician) to look it over and take their advice.


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## Jake (29 Jun 2008)

Tony":3d6hmoua said:


> Personally ... I would get an electrical engineer (not an electrician) to look it over and take their advice.



That's much better advice - although I'd trust a good electrician myself.


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## Digit (29 Jun 2008)

A pest officer would have been my advice in my own case at one time. Bloody mice made a right mess of the wiring in my loft at one time. Took months to find out how they were getting in. 
Whilst broadly agreeing with you Tony it is an unfortunate fact of life that many people have little or no interest in electrical safety if they have to pay for it. 
Before RCDs became the norm I found it near impossible to get householders to pay for the extra safety that they engendered. 
It also true in all fields of domestic installation that the customer will normally go for the cheapest option, this puts the installer under pressure to cut corners. 
When I moved into my present home we had ironclad circuit breakers and a grand total of two sockets. 
I rewired the entire place myself. Each section of the house is on separate ring circuits, the lighting circuits are also split. 
Separate circuits have been installed for out door supplies, including lighting. 
Both workshops and garage are similarly wired and each has its own RCD, as do the out door supplies. 
All horizontal cabling is pegged every 18 inches and all vertical runs are pegged every 9 inches. 
I very much doubt the most sparks would even bother to offer customers such an installation because of the cost in parts and labour. 

Roy.


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## Woody Alan (29 Jun 2008)

> That's much better advice - although I'd trust a good electrician myself


Yeah me too
Alan


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## gasmansteve (29 Jun 2008)

Tony
I asked on an `amateur woodworkers` forum because I thought there maybe some qualified persons who apart from being woodworkers may actually work within the industry and be able to offer some unbiased advice as indeed I would be happy to do if asked as an experienced gas engineer and also (very amateur) woodturner :wink: 
Cheers
Steve


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