Leaks in copper pipe…..

[Heatslave]

Can anyone explain this to a confident and competent DIY’er please ?? It’s a bit long winded….sorry.

A couple of years ago I ran 15mm copper pipe along a cut out channel on the edge of a concrete floor in the kitchen, which was subsequently covered with laminate. Today I heard a faint hiss in the pipework to it in the garage next door. After getting very anxious and stressed I lifted the laminate to reveal a leak in the pipe where there is no joint. It was brand new copper from Screwfix. From how wet and damp the concrete is, it’s been leaking a while . I purposely used one length of pipe all the way through the channel to ensure no leaks at any joints. Before anyone asks, I purposely didn’t use plastic because I don’t trust it, and prefer traditional copper for the reasons most good old fashioned plumbers use it. It’s never let me down in the past.

Just to add, last month I found a pin prick leak in the same pipework in the garage which leads to the kitchen pipe leaking now. That had been leaking for months and months, but it was hidden by the foam insulation. I put that down to the person who fitted that pipework damaging it with a pipe bender, but I’m not so sure now.

You can see the discolouration on the copper, and the corrosion near the plastic clip, but there was no joint there for flux to be. I’m at a loss as to what’s happened and why, and what to do for a permanent fix ??

(All pipework was covered in foam insulation)

 

[Deleted member 267285]

Hard to say, but could have reacted to something or flux wasn’t flushed out?

 

[terryplumb]

Cut a section of the pipe out ,around 1 foot length,and look at the inside of the pipe. If there are multiple little lumps ,it's pitting,and corroding from the inside.

 

[Heatslave]

Cut a section of the pipe out ,around 1 foot length,and look at the inside of the pipe. If there are multiple little lumps ,it's pitting,and corroding from the inside.

Thanks for the reply

On two year old Wednesbury copper pipe, on a cold water tap supply ?? I just don’t see how two year old copper pipe can have holes in it in that short a space of time ??

I’ve never had any issues with copper pipe in the twenty three years I’ve been using it in this house. Has there been issues with the standard of copper pipe recently ??

 

[Alec_t]

Is the leak point where the laminate underlay was in contact with the pipe? If so, there could have been a chemical reaction between the two.

 

[Heatslave]

Is the leak point where the laminate underlay was in contact with the pipe? If so, there could have been a chemical reaction between the two.

No…..all the copper was covered in bog standard foam insulation. And thankfully the laminate had plastic sheet under it, or that would be ruined too

 

[danfre]

Have the earth checked by a electrician, it has been said that a bad connection may cause pinholes in pipe work

 

[Harry Bloomfield]

Have the earth checked by a electrician, it has been said that a bad connection may cause pinholes in pipe work

A tiny voltage, between a cable, and the pipework, if the cable is bare, and has a small area of contact with a pipe, can erode the pipe, to create a pinhole. I don't see any cables in proximity to these pipes.

 

[Heatslave]

Have the earth checked by a electrician, it has been said that a bad connection may cause pinholes in pipe work

For what it’s worth, and beyond my DIY understanding…..my electrician who recently put in a new MCB said there was no earthing necessary on my pipes, or MCB, etc, due to the type of electric cabling coming into the house.

 

[Heatslave]

Could it be I’ve just had a bad batch of copper pipe ??

The manager at Screwfix said he never gets any complaints about Wednesbury pipe.

 

[bernardgreen]

A metallic pipe that is "Earthed" by a bond wire to the Earth terminal in the Consumer Unit may be at a different potential to the Ground around the house. If there is dampness that provides an electrical path from the Ground to the pipe then current flowing through that path could be corroding the pipe.

 

[bernardgreen]

The manager at Screwfix said he never gets any complaints about Wednesbury pipe

Then be sure to buy only on a Wednesday and avoid all other days.

 

[Heatslave]

Could it be I’ve just had a bad batch of copper pipe ??

A metallic pipe that is "Earthed" by a bond wire to the Earth terminal in the Consumer Unit may be at a different potential to the Ground around the house. If there is dampness that provides an electrical path from the Ground to the pipe then current flowing through that path could be corroding the pipe.

I appreciate that reply, but it is well beyond my comprehension

There is no physical earthing strip to my MCB, the electrician said it’s not needed, and the only electrical connection to the copper would be through the Worcester oil fired combi boiler.

 

[Heatslave]

Although I hate the stuff, I’m really losing my faith in modern copper, and I’m thinking of using plastic pipe under the laminate. This will eliminate the corrosion risk, and can be done with no joints. There’s no chance of rodent infestation, so it may be the answer ??

 

[bernardgreen]

it is well beyond my comprehension

In simple terms the "Earth" in the consumer unit ( Fuse box ) is often connected to the incoming Neutral in the supply cable. The Neutral should be at the same potential as the Ground but in reality it can be several volts different from Ground potential.

There is no physical earthing strip to my MCB, the electrician said it’s not needed,

That is rediculous and suggests your "electrician" lacks the basic knowledge necessary to work on electrics. You need a electrician to check the installation for safety of people in the house.