Cable in concrete trench corroded

[maccaandy]

Hi,

A few years ago I had some cables run from my fuse board to my kitchen. The cables were laid inside my house through the concrete base. There was a long trench dug through the house, and the cables laid into it. Now, a few years on, I've had a qualified electrician confirm that the cables which were laid have corroded and need to be replaced.

Does anyone know what the regulations are with laying normal PVC cable in concrete? Should it have been put in conduit to protect it? The qualified electrician I recently had said I could claim against NAPIT for incorrect installation, but I need to work out if it was actually incorrectly installed or not. I've attached a picture of the cables going straight into the ground.

Does anyone have any advice on this please?

 

[brianmoooore]

I have seen a lot of cables in wooden trunking buried. Not a good idea buried.
In concrete.

Wooden trunking above DPM should be fine. Used to be a common installation method for copper pipes in floors - two lengths of 2X1 batten laid on edge, with a 10mm plywood cover on top, then screed laid flush with the top of the plywood.

 

[cliffed]

Hopefully there’s a duct somewhere in the ground if you can find it….you could dig around the cabling & see if you find the duct & look at the cabling to see if they are damaged

 

[OnlQQker]

Mixture of new and old cable by the looks of it, and is that a 28/22mm copper pipe dropping into the floor?

If so is it gas?

 

[Midwest]

PVC cables buried in concrete. Doesn't seem like a good design. Last time I did some concreting, I ended up with very chapped hands.

 

[7029 dave]

I have provided 2 new circuits chased in floor when my mates parents had their kitchen revamped.
His dad was an architect and instructed me to do it, that your route. lol Was not keen but hey he was the boss never had any comebacks done that job mid to late 80's. Plastic conduit used.
His parents are long gone RIP and he now lives in the USA

 

[westward10]

I want to know how they know they have 'corroded' have they pulled the concrete up.

 

[7029 dave]

Those cables look inline of route to that copper pipe.

 

[MJPD29]

Surely they are in a duct if you dig down a little, not a great idea to leave twin and earth on the floor and screed over it

 

[Pretty Mouth]

Table C1 in the On Site Guide does say that twin and earth is unsuitable for embedding directly in concrete.

 

[7029 dave]

Table C1 in the On Site Guide does say that twin and earth is unsuitable for embedding directly in concrete.

With due respect the onsite guide is not BS7671

 

[nicebutdim]

With due respect the onsite guide is not BS7671

It's not, but I wouldn't consider this to be particularly bad advice.

 

[7029 dave]

It's not, but I wouldn't consider this to be particularly bad advice.

Fair point dim

 

[Pretty Mouth]

With due respect the onsite guide is not BS7671

Does BS7671 offer advice of this nature?

 

[7029 dave]

Does BS7671 offer advice of this nature?

No

 

[mainline]

Does BS7671 offer advice of this nature?

Bs7671 could be helpful in this respect, you can tear up the pages and wrap it around the cable before burial, it may afford some protection.