chasing into concrete screed floors - a risk to the neighbour's lights?

[laike]

i live in a 1960s built ex-local authority flat. the floors are concrete with approx 30mm of screed poured on top, brick walls. the existing cabling is all MICC which i'm considering ripping out, not because it doesn't work but because i'm looking to move some walls and chase new central heating pipework into the concrete floors. am pretty certain this is going to nick an MICC cable and the circuit will be screwed. not to mention it's not much more expensive to do a full rewire than to find someone who can repair MICC.

QUESTION:if i'm chasing into the screed to run my new cables, is there a risk that i could cut the neighbour's below me lighting cables? is there a chance their lights are running through my screed? (if not, how did they possibly run their lights to their bedroom as their ceiling / my floor is concrete?)

really frustrating job this, if there are any certified NICEIC sparks reading this who are keen to take it on, get in touch. location: dalston, london.

 

[Knobhead]

I would recommend you talk to a structural engineer before you do anything.

A quick question. Are the floors cast or pre-stressed beams?

 

[dave274]

their lights will be run either in the plaster on their ceiling or above plasterboard on their ceiling. I think its highly unlikely they drilled through the concrete into the flat above and ran the cables across your floor. but im with napit so my opinion is worthless to you.

 

[laike]

but im with napit so my opinion is worthless to you.

sorry mate, no need for the passive aggression.

any of these qualifications would be acceptable:

NICEIC (National Inspection Council for Electrical Installation Contracting)
NAPIT (National Association of Professional lnspectors and Testers)
ECA (Electrical Contractors Association)
ELECSA - Owned by the Electrical Contractors’ Association (ECA)
BSI (British Standards Institution)
BESCA (Building Engineering Services Competence Assessment)
Benchmark Certification Limited (Benchmark)

requirements specified by the council...

 

[AndyOz]

Quick answer to your question is that it is unlikely that the downstairs lights are in your floor, but not impossible. A full survey before any work takes place is essential. As Tony says you need to understand the structural impact on this work as well as electrical. I applaud you for using a competent electrician, just understand being a member of the schemes you mention does not guarantee competence.

 

[ayjay]

micc would have been clipped to the ceiling slab then skimmed over i reckon
check your flat to find out the method of wiring

 

[laike]

thanks for the advice all. the council surveyor gave similar advice, to get a structural engineer to give approval but in his opinion chasing into the screed should probably not pose a problem to either the structural integrity nor the cables to the flat below.

if any electricians reading this still up for a full rewire, please get in touch. cheers.

 

[laike]

micc would have been clipped to the ceiling slab then skimmed over i reckon
check your flat to find out the method of wiring

in my flat (i live in a 2-story maisonette) the lights on the lower floor go into copper boxes in the concrete ceiling, which i assume then drill through into the screed above, run across the floor, down the walls, etc. there are no cables clipped to the ceiling that i can see - i'm pretty sure i've stripped it down to the concrete and it is flush.

the council surveyor agreed it is 'very unlikely' the flat below would have cables running on my side of the floor, however. perhaps they clip & skim as suggested on their side.

 

[somersetsparks]

Have you thought about battening the ceiling for your cables and pipes? I would not entertain chiding screed tbh, although I doubt the cables for downstairs are in there.

 

[Geordie Spark]

<< really frustrating job this, if there are any certified NICEIC sparks reading this who are keen to take it on, get in touch. location: dalston, london. >>>>>>>>>>>>>>>

What's so special about NICEIC ???????????

Get on my ---- this does. :32:

 

[AndyOz]

Calm down Geordie Spark, read post #4.

 

[SPARTYKUS]

<< really frustrating job this, if there are any certified NICEIC sparks reading this who are keen to take it on, get in touch. location: dalston, london. >>>>>>>>>>>>>>>

What's so special about NICEIC ???????????

Get on my ----, this does. :32:

moobs...?

 

[johnboy6083]

I agree. I get to see the work done by NICEIC sparks, and a lot of it is shoddy.
By the way, I work for an NICEIC firm, I do the inspection & testing, and Ive never met the NICEIC man.

 

[laike]

Have you thought about battening the ceiling for your cables and pipes? I would not entertain chiding screed tbh, although I doubt the cables for downstairs are in there.

why not? I have considered battening ceiling tho that would be required in 3 rooms and then I'd have surface mounted cables and pipes upstairs - figured it's better to do the entire job properly, full repipe and rewire chased into the floor and walls.

have an appointment with a structural engineer tomorrow for £450 + VAT.

 

[laike]

<< really frustrating job this, if there are any certified NICEIC sparks reading this who are keen to take it on, get in touch. location: dalston, london. >>>>>>>>>>>>>>>

What's so special about NICEIC ???????????

Get on my ---- this does. :32:

I've been trying to hire an electrician off the net, you get people saying they're 'qualified', the council says they require proof of the certifications posted above and they can't provide it. Apologies I only posted niceic, it's just the first one that came to mind. The point was that I required someone with certification to please the council who will inspect the work.

 

[stuartcourt]

cant believe we dont have a London based domestic spark on here who is interested (sure someone will be)

 

[KAS1]

What a load of tosh " not to mention it's not much more expensive to do a full rewire than to find someone who can repair MICC ." repairing MICC is as easy, that was first year apprentice stuff lol

 

[Dipzy]

Hi Laike,

pm sent.

 

[Knobhead]

why not? I have considered battening ceiling tho that would be required in 3 rooms and then I'd have surface mounted cables and pipes upstairs - figured it's better to do the entire job properly, full repipe and rewire chased into the floor and walls.

have an appointment with a structural engineer tomorrow for £450 + VAT.

Good man. You don't want a vertical close encounter with downstairs.

 

[Geordie Spark]

Calm down Geordie Spark, read post #4.

Sorry bonny lad ........... Aahve not supped me day's quota of Broon yet.

 

[Marvo]

C'mon guys, please cut him some slack with the NICEIC thing, he's obviously not in the industry so it wasn't a malicious comment.

With regard to the questions in the OP there's still many sparkies around who can work with the mineral insulated cabling. Secondly with a little time and a cable-finder or tone set there's no reason an experienced electrician couldn't map out the existing cable runs fairly accurately. Finally I'd suggest you have all the circuits tested for continuity and insulation resistance before you plaster up any chases, that way it will be easier to localise any damage you may have caused.

 

[Geordie Spark]

What a load of tosh " not to mention it's not much more expensive to do a full rewire than to find someone who can repair MICC ." repairing MICC is as easy, that was first year apprentice stuff lol

Aye, but that was back in the day when folk received "proper" training spread over 5 years ... NOT five weeks !!!

 

[Geordie Spark]

C'mon guys, please cut him some slack with the NICEIC thing, he's obviously not in the industry so it wasn't a malicious comment.

With regard to the questions in the OP there's still many sparkies around who can work with the mineral insulated cabling. Secondly with a little time and a cable-finder or tone set there's no reason an experienced electrician couldn't map out the existing cable runs fairly accurately. Finally I'd suggest you have all the circuits tested for continuity and insulation resistance before you plaster up any chases, that way it will be easier to localise any damage you may have caused.

Sorry Marvo. :sad_smile:


Are we still friends?:love:

 

[Marvo]

No probs, I know you're a sweetie at heart

 

[Knobhead]

C'mon guys, please cut him some slack with the NICEIC

Why ? ?

 

[Marty203]

i live in a 1960s built ex-local authority flat. the floors are concrete with approx 30mm of screed poured on top, brick walls. the existing cabling is all MICC which i'm considering ripping out, not because it doesn't work but because i'm looking to move some walls and chase new central heating pipework into the concrete floors. am pretty certain this is going to nick an MICC cable and the circuit will be screwed. not to mention it's not much more expensive to do a full rewire than to find someone who can repair MICC.

QUESTION:if i'm chasing into the screed to run my new cables, is there a risk that i could cut the neighbour's below me lighting cables? is there a chance their lights are running through my screed? (if not, how did they possibly run their lights to their bedroom as their ceiling / my floor is concrete?)

really frustrating job this, if there are any certified NICEIC sparks reading this who are keen to take it on, get in touch. location: dalston, london.

I have not worked in the UK for years but I did work on a lot of high rise buildings when I was there, if the wiring is Pyro (MICC) then it will be clipped to the underside of the ceiling slab of that flat with shallow boxes and plastered over, if it is wired in steel conduit then it will be on the concrete slab of your flat and screeded over, the way to check would be to remove one of your lights and look to see if there are conduits leaving the top of the box and the wiring is PVC insulated or if Pyro enters from the side.

 

[SPARTYKUS]

Yep, gota flat in steel condo in the concrete.

makes moving the light switch a bit of a job

 

[Engineer54]

I have not worked in the UK for years but I did work on a lot of high rise buildings when I was there, if the wiring is Pyro (MICC) then it will be clipped to the underside of the ceiling slab of that flat with shallow boxes and plastered over, if it is wired in steel conduit then it will be on the concrete slab of your flat and screeded over, the way to check would be to remove one of your lights and look to see if there are conduits leaving the top of the box and the wiring is PVC insulated or if Pyro enters from the side.

If a conduit installation, the conduit runs would be within the slab, installed just after the steel re-bar fixers, with the conduits tied to the re-bar. Never seen a conduit installation run on top of the slab, as for anything else, it would be out of it's installations equipotential zone, if located as you state, especially if were talking for a block of flats situation....

 

[UNG]

Back in my college days pyro was covered with a number of sessions including a number of videos produced by BICC for colleges one of those videos detailed the manufacture and use of what they called the Octopus system this consisted of a number of pre terminated pyro's connected to a central adaptable box and a box at the other end to suit the accessory that would be fitted at second fix. The pre made octopus was manufactured to suit each installation / building type on site this was secured to the ceiling / floor shuttering prior to the concrete being poured,

I have tried to find this video on the web but I've not had any success to give an insight in to how pyro was used in some cast concrete buildings, I think octopus system was used in the sixties and early seventies so if you property was built around this time it is possible this system was used

 

[Marty203]

If a conduit installation, the conduit runs would be within the slab, installed just after the steel re-bar fixers, with the conduits tied to the re-bar. Never seen a conduit installation run on top of the slab, as for anything else, it would be out of it's installations equipotential zone, if located as you state, especially if were talking for a block of flats situation....[/QUOTE

Thats how we do it here and have done since day one, but in the 60's in the UK the steel conduit was laid on the top of the slab, the holes for the lights were formed when the slab was poured and there was a 100mm soft screed laid over the slab which covered the conduits, heating pipes etc, I dont know how they do it now, you may have never seen it but thats the way it was done all over the country and if you could bend the stuff and you could earn a fortune as most sparks were paid per flat for first fix