House rewired - find cables were run just under floorboards

Lewis123 · Mar 5, 2012

Hello,

A few years ago I had my house rewired and received a Building Regulations Compliance Certificate from the installer. I've recently had to raise some floorboards and now see that the installer in many cases ran cables through notches in the joists and these cables are not protected from nails that might be hammered through the floorboards. I believe this is against wiring regulations. Also some cables run in notches side-by-side with hot central heating pipes which doesn't seem safe to me. I have only just discovered this and I haven't yet contacted the installer. Can anyone advise me about the sort of remedial work I should be asking for?

Thanks,

Lewis

Knobhead · Mar 5, 2012

Speak to the installer first, I for one will not past the stones for you to sling.

We are here as tradesmen, and as such should not pass judgement on the word of a novice.

gaz2212 · Mar 5, 2012

Seems you've already decided its wrong!!!?

piratebillybob · Mar 5, 2012

i thought you were allowed notches but they had to be withing specific zones and specific depths

telectrix · Mar 5, 2012

notches only allowed if 3mm thick steel safe plates fitted over cables.

needasparks · Mar 5, 2012

Who's to say these are new cables and not old ones not pulled out.
I would say best to speak to the installer and discuss your questions.

trev · Mar 5, 2012

You said "A few years" How many is a few please mate?

D80 · Mar 5, 2012

trev said:
You said "A few years" How many is a few please mate?

Is the "Building Regulations Compliance Certificate" not something related to Part P?

If so not many years ago!

trev · Mar 5, 2012

I thought so too mate, just wanted to confirm the timescale

Snapester · Mar 5, 2012

The cables should be protected by metal plates which will fit over the notches this will cover the protection of the cables in the notches, the notches may have been there from previous installation work.
As for running next to the hot pipes are they plastic or copper? Its a bit of a no no for me running next to hot pipes as i have seen them burn't through common sense should prevail on these faults.

D80 · Mar 5, 2012

Also I thought a notch in the joist in the centre of a floorboard was ok? I drill joists so its not generally an issue, but was under the impression the centre of the floorboard was ok, and seen heating pipes a plenty put in this way.

D80 · Mar 5, 2012

Snapester said:
The cables should be protected by metal plates which will fit over the notches this will cover the protection of the cables in the notches, the notches may have been there from previous installation work.
As for running next to the hot pipes are they plastic or copper? Its a bit of a no no for me running next to hot pipes as i have seen them burn't through common sense should prevail on these faults.

With regards to this, it depends what was in first. Had a job in the middle of last year and the plumber had his pipes all over my cables, despite my stuff being in weeks before. Took a lot of effort to get him to move his pipes, I doubt its an isolated case though!

GLENNSPARK · Mar 5, 2012

Snapester said:
The cables should be protected by metal plates which will fit over the notches this will cover the protection of the cables in the notches, the notches may have been there from previous installation work.
As for running next to the hot pipes are they plastic or copper? Its a bit of a no no for me running next to hot pipes as i have seen them burn't through common sense should prevail on these faults.

well there such a thing as mutual determental influences as well.....to be found on a schedule of inspections....

Snapester · Mar 5, 2012

Yeah this is true as you say i have seen pipe installed afterwards and well plumbers don't give a t**s do they, its good practice to cover notches with plates i have myself been pulled up by my NICEIC inspector on this exact thing, even though they were in the centre of boards?

Rockingit · Mar 5, 2012

Plumbers have no respect for cables whatsoever in my experience. I had a right go at one the other week who's genius had decided to fit a pump so close to an SWA that the (hot) brass locking nut was squashing into the insulation!

But back to the OP - don't be too quick to jump to conclusions - you may well find that there was good reason for reusing old notches. I've found joists before where the plumber (of course) has put notches in them so deep that the structural integrity was probably 10% of what it should be, so in that case you don't want to go making any more. As others have said - talk to your installer first.

D80 · Mar 5, 2012

To the OP - why have you got the floorboards up?

sjm · Mar 5, 2012

Where did this idea of notches "in the centre of the floorboard" come from??
Cables passing through a joist must be 50mm from the surface or protected from penetration by the use of a plate, as others have said, be in earthed steel conduit or have an earthed metallic covering.

telectrix · Mar 5, 2012

many years ago, before my time, even, cables were singles, run it wooden channel, notched into the joints. the wood channelling would be installed by a carpenter ( now known as wood butchers), so he would know where not to nail. at the time, the only form of central heating was an overcoat, so no problems with plumbers either.

Lewis123 · Mar 6, 2012

Thanks for useful replies. To answer one, the rewiring was done about six years ago. And to answer an earlier one, I'm not looking for ammunition, I'm just trying to get an idea of what it's reasonable to expect which is why I asked this forum before taking the matter up with the installer.

Lewis

mickys86 · Mar 6, 2012

Let us know the outcome please

Darkwood · Mar 6, 2012

The notches may be existing and utilised for the rewire, this maintains the integrity of the joist as it may not be possible to re-drill holes without compromising the structural integrity of the joist.... as said above; you need to discuss this with installer for his reasoning.

Amp David · Mar 6, 2012

I've just first fixed a rewire and reused the existing notches. Had to, floor joists are only just over 3 inches deep! All notches are positioned in the middle of the super wide floor boards and as all ceilings had been dropped, there was no way i was lifting boards to plate over the notches.

Went back a day or 2 later and my plumber friend needed to get his heating, cold and hot feeds around the house, so guess what, 4 lots off 25mm holes drilled no more then 20mm apart to get his pipes through.

What is that all about. TBH i've given up wasting time worrying over little things like this, more important things to be getting on with.

mozzo · Mar 6, 2012

The installer would have the answers for doing the work the way he has but on another note people are generally looking to go for the cheaper price for an installation and installers are bringing prices down to get the work. How many people out there make a choice based on quality of work and professionalism and are prepared to pay more to get a high standard of finish that will usually take more time and cost more in materials. Not saying this example is due to a cheap install but these are the problems that are out there that is contributing to work not being done to code. Half the problems you see people requesting help on sites like rated people is probably down to cheap installs, wrong materials and erection methods etc as a result of going for cheap price. As I say how many people go for quality which generally = more money as the first choice

Amp David · Mar 6, 2012

Hardly anyone nowadays

cbw · Mar 6, 2012

WHY on earth would you want to drill a hole next to a perfectly good notch???

Always reuse existing holes/notches

And am I old fashoined with the notches in first 25%, holes in the next 50% and then notches in the last 25% again, with restrictions on the very edges and center???