Extension

[davethsparky]

Re: how not to wire your extension

You really need someone to attend the site and look over the installation and all of the pictures you have to give you an accurate report on the installation. But I would suggest that based on the pictures you've been done over by a cowboy!

A few points that stick out to me are:

You have cables installed across the floor which have no doubt been trampled by everyone working on site so the insulation and sheath will likely have been destroyed, possibly may even have short circuits in the cables already.

may need to install bonding to bridge the plastic joints in the copper pipe, cant see where it goes or what it does but this needs checking.

Cables installed behind the plasterboard not in the safe zones and not protected from penetration by nails, screws and the like.

There appear to be choc blocks stuffed in the wall where a socket has been removed.

An outside light point with the bricks hollowed out a bit and choc blocks in it next to the old extractor outlet.

The cables across the floor will be exposed to cement slurry when it is applied to the floor, that cable coming into contact with cement, especially whilst wet, is a big no-no as far as the regulations are concerned as it can damage the cables

 

[jonwade]

Re: how not to wire your extension

The plastic pipe is for the pipe that connects the outside tap.

What is a safe zone?

I guess choc blocks are the white plastic connectors - I saw these taped up. Is that sufficient?

The cables on the floor were covered with the waterproof membrane. I know the builder mentioned slurry weeks ago, not sure how this would now come in to contact with the cables?

I will see if I can get somebody to look, but my builder has been doing extension for over 20 years and used to be qualified to do electrics, but now gets somebody else in to check the electrics. I think this is tomorrow. Maybe I will ask a few questions like "is it OK without conduits?".

 

[davethsparky]

Re: how not to wire your extension

Whoever he is getting to look at it will say it is fine regardless of the condition and ten take his cash and run!

The cable shouldn't be under the moisture barrier and then pass up through it or round it as this can provide a path for moisture to get past the barrier. local authority building control should be able to advise on this better than I can.

Doing electrics for 20 years doesn't qualify him for anything, it just means he may have been doing it wrong for the last 20 years.

Taped up choc blocks is not sufficient for anything! connections must be made in a suitable enclosure and teh cables secured so that no strain can be put on the connection. and if any form of screwed connection is used it must be left accessible.

The cables on the floor will now be underneath the insulation which will affect their current carrying capacity, they may very well need to be a bigger size to allow for this depending on the type of circuit installed and the design.

Ask him to prove he has installed the correct cable size by showing you the calculations he carried out when designing the circuit. He will likely say it is a standard circuit and doesn't need calculating, ask him to show you this standard circuit in his regulations book (thsi isn't a trick question they are in there)

Ask for his mate who checks it's part P scheme registration number and contact the scheme operator for help.

A safe zone in this situation is the zones of the wall in which cables may be buried without additional mechanical protection against penetration and or and earthed metal covering. There is a good picture in the on-site guide which eh will be able to show you if he has a copy as he should have if doing this work.

The situation with regards earthing the pipe would need to be looked at on site, as it will be buried in the screed it could become an extraneous part and need bonding, but that really does need looking at in the flesh.

Personally I wouldn't be happy to have anything other than properly soldered plumbing connections buried anywhere, but maybe that's because i've seen too many leaking joints under screed floors.

 

[davethsparky]

Re: how not to wire your extension

A quick google search found this which gives an idea of how the safe zones thing works

Cable Safe Zones | Flickr - Photo Sharing!

The cables in the pic in post 13 don't appear to be in a safe zone

 

[gutterball]

Re: how not to wire your extension

where do the cables for the extension come from? are they off a socket or directly into the consumer unit. are they rcd protected.
when the guy comes to test ask him to show you the ir test for the cable run across the floor. there's a good chance that its been damaged.

 

[davethsparky]

Re: how not to wire your extension

Damage possibly won't show on an IR test straight away, just wait until the moisture gets into it as its on the wrong side of the moisture barrier!

 

[gutterball]

Chances are that if its the builders mate it will ba a drive by.

 

[jonwade]

Re: how not to wire your extension

Does anybody know someone in Chelmsford who would be able to look and advise?

I am at a loss what to do, getting in a panic.

Left message with building control. Will speak to the builder about it, but sounds like this could put back building by days which is a PITA. Want it done right though.

 

[Dubbo]

Re: how not to wire your extension

Does anybody know someone in Chelmsford who would be able to look and advise?I am at a loss what to do, getting in a panic.Left message with building control. Will speak to the builder about it, but sounds like this could put back building by days which is a PITA. Want it done right though.

I would say let the screed go down then find someone qualified to rewire the sockets properly using a different route, I could pick lots of faults with the job like gaps around insulation and rock wool put in were Celotex should be used , no dpc barrier were the extension walls join the existing property they should of been cut with sthil saw and dpc inserted to stop bridging, to me he has no pride in his work for small details finished job may look ok but under the surface is rough sorry to slate just been honest

 

[danzor]

This is your house jonwade? Someone just found a random link to your extension? Or have I missed something

 

[jonwade]

Re: how not to wire your extension

Danzor, it is my extension.

Dubbo - this is what my wife suggested. Once the build work is completed we could get an electrician in to fit a proper junction box on the socket that feeds the extension and then re-test all other sockets. Maybe then, worse case scenario is running new cables through the walls and re-plastering and painting. Maybe not the end of the world.

I am keen not to upset things, these builders did come recommended and have been doing extensions for 20 odd years. As Davethsparky said, does not mean they are great electricians of course.

I had a plumber look and he said that while he would personally also solder, the push fit connections are now designed for mains so OK.

I spoke to Building Control and they said that they do not look at electrics but so long as it is all checked a cleared by an electrician it is considered OK.

From all the great advice here, I think it possibly comes down to:

1. The 2 choc blocks are not ideal and maybe they could be replaced later with a proper junction box.
2. The main cable which runs across the floor should be checked on a regular basis to test for wear/tear.

Regarding insulation, to rock wool was only used in the roof above the Celotex - 2 layers of insulation were pout up there, all in line with architect design and building regs. The walls had similar sheets of cavity wall. The roof is solid - over engineered according to the building inspector, I have no issue with that.

I will take Dubbo's advice and invite a local electrician to take a good look, ideally between the builders finishing and building control doing their final inspection.

Going back to the floor - could the cable really get damp? The block and beam sits on the damp course bricks, they are aired underneath (suspended). So the layer between the sheet and the blocks (where the cable is) should not get wet should it? I cannot see how any water / moisture would get there (not saying it can't!).

The safe zone is something to consider - I guess this can be sorted later too - remove plaster / board, fit and re-plaster?

If some of the building work is not up to today's standard I am more keen to get it completed and then reviewed, rather than ask the builders to change everything. This will cause even more stress I think.

Thanks again for your advice - I know the thread started out as a "look at this rubbish work!" thread but it has proved very useful to me. Although maybe next time make contact privately first and suggest solutions?

Cheers

Jon.

 

[trev]

Re: how not to wire your extension

Jon you're paying for this job and so are entitled to it being right when it's completed, all this talk of removal of things then recitification then refitting is madness imho. All it will do is cost you more, there's a few lads on here from down your neck of the woods. Dave85, Essexboy7 and a few others, there's a thread somewhere, electricians unite I think, called find an electrician in your area trawl through it and find someone who can come and take a look at this BEFORE it goes too far mate.
Now obviously, me being on Tyneside, there's no way I can vouch for someone's work who is in Essex but there's been a few who have had Essexboy7 referred to them and not one has ever come back on here complaining about him so make of that what you will.
Please don't leave this till it's too late as it will only cost you more money, stress and strain on your relationships with your loved ones.

 

[jonwade]

Re: how not to wire your extension

Thanks.

 

[davethsparky]

Re: how not to wire your extension

Danzor, it is my extension.


2. The main cable which runs across the floor should be checked on a regular basis to test for wear/tear.

No it should not be installed in such a way that it can sustain foreseeable and predictable damage. If it has to run under the screed then it should be installed as close as possible to the time when the screed goes down and be provided with adequate protection against damage.

 

[davethsparky]

Re: how not to wire your extension

Danzor, it is my extension.

Going back to the floor - could the cable really get damp? The block and beam sits on the damp course bricks, they are aired underneath (suspended). So the layer between the sheet and the blocks (where the cable is) should not get wet should it? I cannot see how any water / moisture would get there (not saying it can't!).

They aren't putting a waterproof membrane in there just for fun! the concern is not so much about the cable getting damp, but of the cable passing from one side to the other of the membrane forming a route for damp to travel in.
Have you asked building control about this? they are the best people to advise on this. I would be getting the building control inspector to come and have a look.

I would also be concerned about their lax attitude towards the electrics, it is a building regs matter (part P of the building regs) and as such they should be there to help you with the matter if you have any reason to doubt that the work is comliant.

 

[Des 56]

Re: how not to wire your extension

The sorry conclusion to this saga was never in doubt
p://www.------.org/forums/forum/messageview.cfm?catid=205&threadid=53932&enterthread=y

 

[davethsparky]

Re: how not to wire your extension

Amazing that so many electricians have looked at it and said it is acceptable!

Am I working to the wrong set of standards or is this just starting to smell fishy?

 

[Des 56]

Re: how not to wire your extension

I can't really comment on the fishy,I had cod and chips for dinner, my own cynical thoughts may be swayed by the taste
I think I should have taken this whole sorry saga with a pinch of salt

 

[dazza1981]

Re: how not to wire your extension

whats the problem? at least they put a couple of clips on the t and e when they installed it to the floor

 

[ExArmy]

Re: how not to wire your extension

Regarding insulation, to rock wool was only used in the roof above the Celotex - 2 layers of insulation were pout up there, all in line with architect design and building regs. The walls had similar sheets of cavity wall. The roof is solid - over engineered according to the building inspector, I have no issue with that.

is that not rockwool between the 2 walls ?
last time i was in the building trade we used to put cavity wall sheets (450mm x 1200mm)of hard foam insulation that had foil on both sides, xtra-therm, kingspan, celotex etc like so
https://www.google.co.uk/search?q=c...b%2Fwalls%2Finsulation%2Fsection4.htm;500;448

the purpose of the cavity wall is to stop damp getting in, and to allow the outer wall to breathe. at a guess the only reason that stuff you have in your walls has been chosen is cos it's cheaper than the cavity batts.