Imperial stopcock issues!

[montanajr72]

Hello,

I am a homeowner looking for advice. The mains water comes into our property via the downstairs cloakroom. House was built late 1970s. We've had three plumbers (local) that have been stumped/unable to remedy the situation.

We're having the downstairs cloakroom refitted, and the original ~40 year old stopcock was replaced. The pipe coming into the property is black plastic, and looks to be imperial. The first plumber filed down the pipe and hammered on a 20mm stopcock nut. This started leaking pretty soon afterwards. Was a slight weep rather than high pressure leak. Second plumber came back and put a bunch of PFTE tape on it, which didn't fix the problem either. Third plumber has bought a 22mm stopcock and an imperial olive, and fitted that. You guessed it, still leaking.

I'm no expert, but it seems to be it would be quite common for properties to have black Alkathene pipes that are imperial, with internal 15mm copper piping. And something would be specific would be needed to replace these old stopcocks. But the three plumbers had the above solutions, and it is now leaking badly (high pressure hissing and water everywhere) and this third plumber is stumped. He says he's aware of black plastic imperial/metric stopcocks, but there isn't enough of the pipe left to get one onto it? The first plumber cut it back.

Any suggestions I, as the homeowner, can pass onto the professionals?!

Thanks in advance.

 

[Brambles]

Use a Philmac imperial alkathene to metric connector. Philmac also do some imperial sizes to metric stop cocks - which avoids the need to convert first.

If the imperial pipe has been cut off too close to the finished floor level - then it is a bigger job and will possibly need the pipe to be excavated back through the floor.

It is not a good idea to bodge the fitting of a mains stopcock - if the joint is failing, it can blow and cause a lot of damage very quickly.

 

[montanajr72]

Thanks Brambles. I've seen the Philmac converters and the plastic stopcocks online, but he is adamant there isn't enough pipe coming out of the concrete floor to get it on. What a nightmare!

Unfortunately, if the first plumber did a proper bodge job, cut off the old stopcock including a fair length of the plastic pipe, and boshed on a 20mm nut with a hammer. This all could have been avoided.

Thank you for your help - appreciate it.

 

[Brambles]

You just have to bite the bullet and cut back into the concrete - you may find that once you have loosened it there is some pull on the pipe - isolate it at the outside stopcock first!

 

[Last Plumber]

You will need to cut the floor back as mentioned above.
You can use a 22 mm stopcock and 3/4" olive but you will also need a sleeve inside the pipe. It should be 1/2" bore so 15 mm tube fits OK normally.

 

[Gasmk1]

Wasn’t this that weird pipe used for a short while that’s an odd size

 

[Warmiger]

As stated break back floor and use a utc. If it’s the bigger black pipe use a 15mm piece of copper pipe is an insert.
Is it the black one that is 17mm in diameter and looks like a black piece of 15mm speedfit?
If it’s this one we use a hep20 insert and 3/8 to 15mm compression coupling. It is rare but crops up from time to time.