Burst pipe under screed mystery

[Rob Foster]

Can't walk away, client is a vulnerable person and it has to be done right. I will carry out the making good at my own cost as on balance of probability it was 'my' fitting that failed. But I would still like to understand the cause and if appropriate let the client know what I think happened.

great man I think I mis understood ..chking

 

[Riley]

Am I completely missing the point or was there a hep fitting on the screed??

 

[Harvest Fields]

I think his contractor fitted it in the screed on to the copper.

 

[Riley]

Well surely that’s the problem never put a fitting in screed?

 

[Sharp Point]

Well surely that’s the problem never put a fitting in screed?

Yep, I’ll never consider using a mechanical fitting in screed.

 

[Rob Foster]

I think his contractor fitted it in the screed on to the copper.

uck

 

[Daniel Adams]

Yes my subbie put the Hep fittings (old 15mm copper - hep20 fitting- hep20 15mm) in the screed, and yes my first thought also was that was why it failed. However in hindsight I don't know why this should automatically be assumed as the I cannot think of a reason why it should fail in screed and not in a stud wall void.

I can understand if it was a new large screed floor because the contraction over time of the screed can cause large movements which might put pressure on the grips and seals between the fittings and pipe. But this would not occur with small screed patches as in this case. I also thought about whether natural expansion and contraction of the rigid plastic fitting in a confined screed could cause a fracture, but then 2.5 years is a long time for this to wait to happen.

What I also wondered was whether the failure of the pressure gauge might cause the homeowner to read zero pressure, and then ramp up the pressure to maximum mistakenly believing that the pressure was not rising. This might cause the weakest point in the system to fail. In an all copper system this could be the plastic to copper joint, but if this had not failed, next would have been a copper joint.

 

[Riley]

Screed will get into the fitting and onto the seals air in a void won’t. Think you’re clutching at straws a bit with the pressure thing as most plastic is good up to 10 bar

 

[Scott_D]

Hep should be tested at 10bar
The boiler prv should open at 3bar so this shouldnt have caused the leak

 

[Daniel Adams]

All joints were well wrapped to prevent any contamination from cement in screed. Did not think about the PRV opening at 3bar. Could it be anything to do with 1 pipe system, that was the other coincidence, first time a Hep20 joint has failed on me and first time I've had dealings with 1 pipe system?