Help me resolve this mains leak?

[saveasteading]

My wife reported a loss of water pressure. I hadn't noticed. Then i saw a puddle outside, and then the meter whizzing around.

So here's the problem. The black pipe is at least 30 years old. The branch off it was to a kitchen extension that we removed. Our plumber (not our usual one) put in a standpipe for us   which is the blue pipe.

When exposed, the blue connection came completely free.

I can't even see how it was connected.*

For now the branch is closed using a sherry cork, string, and densi tape. There's a constant drip, so I will monitor  and turn it off overnight.

 

I've got myself various joiners today. 

The next issue is that i oubt if the old fitting will unscrew  so I will have to cut the pipe.

I'm thinking of a junction, then cut off a bit of black pipe and add a straight connector to make up the length. I should have bought 100mm of blue pipe.

Then a reducer towards the standpipe.

Also thinking of adding a stopcock.  Any thoughts and suggestions?

 

*a total bodge. The backfill was fill of big stones and rubble. The black pipe is propped up on a bit  of brick.

[ProDave]

Is that tee in the black pipe a brass compression fitting?

[saveasteading]

29 minutes ago, ProDave said:

s that tee in the black pipe a brass compression fitting?

I think so. I haven't used ultimate force with two wrenches yet, but I'm not expecting them to come loose.

 

I really don't want to wreck the mains supply with 4 working days to Christmas.

 

I don't know if the black pipe size is completely compatible with blue either, and they didn't know at the BM.

[ProDave]

The black could well be imperial.

 

What I was getting at with the brass tee, is can you undo whatever is screwed onto the tee?  and then find a fitting that will go from that to the blue mdpe?

 

Best wait until the new year when the merchants are open again, you have managed the leak well enough for now.

[Conor]

The black pipe will be imperial sized alkathene. Remove the tee. Fit a universal coupler, something like 22-29mm OD to 25mm MDPE. Then a short length of 25mm MDPE pipe, then a 25mm tee. I'm assuming that's all 25mm, you've not specified. You'll need to make that hole a good bit better to get the space.

 

Don't use brass compression fittings!!!!

[Russell griffiths]

You will want to look at changing the black alcathene pipe completely soonish. 

They tend to be very thin wall, and 30-40 years they start failing. 

I repaired my neighbours one 4 times before I convinced her to change the whole thing. 

[ProDave]

1 hour ago, Russell griffiths said:

You will want to look at changing the black alcathene pipe completely soonish. 

They tend to be very thin wall, and 30-40 years they start failing. 

I repaired my neighbours one 4 times before I convinced her to change the whole thing. 

I remember as a boy my dad doing some work under the floor and installing a black alcathene pipe to "replace the lead pipe"  That was about 40 years or more ago and as far as I know the black pipe was never connected and the lead is still in use.

[saveasteading]

Thanks all. 

I will check properly, but I think the black mains pipe is about 32mm inch externally,  Some research shows that this is called 1" because that is the ID, and is also stated as 24.5mm ID and 33.7mm OD.

Yes, I know that an inch = 254.mm so i will find another reference to check.

The branch is blue mdpe  25mm.

 

i also see that I will not 'win' any black pipe when fitting a new branch  as the pipe goes nearly all the way into the socket.

 

so I will need to buy some 35mm mdpe,. nobody seems to sell it by the m so I will have 24.5m spare.

But it might be as well to replace a metre or so while I'm at it.  IN one direction it is easy digging.  The other soon disappears under concrete!

 

Apparently we can tell that alkathene is failing when black bits come out of taps.  something to look out for.

 

Ive turned the water off for the night . My cork and string thing is working, and i think the leak is now at alkathene to brass. 

The puddle has grown considerably but its a leak, not an outpouring.

 

Tomorrow I have other things to do, so I will get back to it on wednesday and report.

 

 

[oliwoodings]

Do you mean 32mm? Found it by the metre on eBay: https://www.ebay.co.uk/itm/114503522757?hash=item1aa8f119c5:g:RdMAAOSwn45Zw51U&amdata=enc%3AAQAIAAAA4MofBLpnApshxOJCvi6P%2FOV%2FYZVJJZTB2ZsuZ%2B13JSvKlOmExq9pfztQGjnd6x3mfs9JqMKw9IH0sRsoagjoF3h%2BBTG0ThnOV7%2Bu%2FRbIVVZNXqjlfKsWyQYDHSfo0ej%2FFC%2FqUvhimNREEExyl0PuYUp%2F5XRmbpyZtJoUaaNtsAYnJkVzGEbqXXxPrKA%2BvwZby%2BMHqFaa9RM1eYlBy6aOCcS4M1RdmnIRA5HYiRqXuew%2BenJo7q6rP6t7eLpuPGEOjnm6VAsShQNycx7ihXZDVYrkHlL%2FHhyw9sWfuuGa7EtP|tkp%3ABk9SR9ac8o-QYw

[JOE187]

From pictures, it looks like a sheared fitting!!

Broken piece should unscrew off imperial tee piece, same for fitting on the 25mm poly and replace?

 Would recommend a short section of 25mm with good curve, the pipe looks like it has been under strain with ground movement.

[dpmiller]

46 minutes ago, JOE187 said:

From pictures, it looks like a sheared fitting!!

Broken piece should unscrew off imperial tee piece, same for fitting on the 25mm poly and replace?

 Would recommend a short section of 25mm with good curve, the pipe looks like it has been under strain with ground movement.

^ yep. Looks like black iron screwed onto the brass?

[saveasteading]

More very messy digging, with every shovel and trowelful sticking.

Is finding more issues progress? Of course.

So there is another joint, looking more modern. That might unscrew.

The pipe was resting on bits of brick and tile, and on concrete dollops on the drain pipe ( I'm guessing they conceal damage). Then just heavy clay backfill with whatever brick or old rubbish happened to be in it.

To the right it bends past the manhole then dives down under the hedge.

So it was clearly stressed.

When repairing it I will loop a generous length of pipe away from the bank to give flexibility. Of course I will backfill with gravel.

 

My big spanner doubles as a measurer, so I  now know the black pipe is 1 1/16th (inch and sixteenth).  This coincides precisely with Internet info saying that an alkathene  3/4" internal pipe has an OD of 26.9mm.

I can't find for sure that this will push into a modern 25mm connector. Surely it does, or there would be special connectors????

 

The blue pipe measures 18mm. Presumably this what you get as a notionally 20mm.

 

Taking @ProDave advice to leave the repair until after Christmas. Too much risk of the merchants being closed or not having stock if there is a change of plan.

My cork and denso is working. A drip every 3 seconds, with the mains valve barely open , but I'm still turning the mains off again night.

 

Oh yes, I found a bit of iron pipe among the mud. 

 

My main concern is whether the black pipe will fit in a 25mm connector.

[kandgmitchell]

Could you use two of these to insert some blue MDPE between them and then put a standard blue mdpe T piece in to your blue?

https://store.jdpipes.co.uk/plasson-plass4-universal-coupling/

 

[saveasteading]

25 minutes ago, kandgmitchell said:

two of these 

Good work. Thanks.

I'd just found these plasson and another make called philmac are the only options ( from a farming online discussion).

I went straight to jdp on Monday but they were closed for stocktaking. 

3 bm later I've got stuff that won't work, but can take it back.

The jdp website just would not find these, but I'll try the depot again.

Plus see if they'll sell me 1m of 25mm blue pipe.

 

Should I buy a proper pipe cutter?

 

[JOE187]

 

www.philmac.co.uk         Down near me and have stockists around the country. 

Have a good technical department  

Philmac

Diplocks Way, Hailsham, East Sussex England, BN27 3JF

01323 847323

0800 590028

[kandgmitchell]

I used a cheap scissor type pipe cutter for my mdpe that I had bought when I was putting in some interior plastic heating pipe. It worked fine - just needed a bit more effort.

[saveasteading]

On 18/12/2023 at 18:33, Russell griffiths said:

changing the black alcathene pipe completely soonish. 

They tend to be very thin wall, and 30-40 years they start failing. 

 

So, I've done it. picture will follow.

The black pipe is quite thick, but softer than the new blue one. also properly black right through.

Given how it dips behind the manhole it is staying put for a while. If it was to leak before this junction then it is an easy job in the lawn, diverting the other side of the manhole.

If after the junction, it is  a big job breaking out slabs.

 

The pipe is clearly very shallow, but freezing is rather unlikely here in SE. Even the outside taps haven't frozen in the last 6 or 7 years. Pus its very local and the rest will be much the same or deeper..

So I may place a slab of eps over the pipes after partial gravel fill. it will also prevent crushing and act as a warning if ever someone decides to dig there.

 

btw, I turned the mains off every night, just in case, and because there was always some leakage.  The denso was gradually being force loose, and the leakage increasing.

 

 

 

[saveasteading]

What have I learnt?

The pipe cutter tool was brilliant. Straight cuts and no bits, in seconds. I expected to have to rotate the tool, like a copper pipe cutter, but it is more like scissors.

So expensive for all those bits and 25m of pipe. About £200, tho that might half if I'd managed discounts (requests politely ignored,  if you are in a hurry).

Only jdp, of 5 merchants, had the right parts for the black pipe connection.

Working with such a concentration of joints is tricky. Not enough flexibility.

Bits falling out of a connector are best not falling in the hole.

TS and SF are getting worse for what is in-stock, so the tools came from Amazon.

 

[ProDave]

Shame you have to buy so much of the 25mm pipe, I am sure I have some short lengths here

[saveasteading]

1 minute ago, ProDave said:

am sure I have some short lengths here

Thanks. I'll remember next time. Could just about do the return trip in a day.

 

The pipe isn't especially expensive at about £1/m, but it is wasteful and will now clutter the garden.

Surely they could sell it at £2/m cut to length?

And it would be visible corporate sustainability if they had an oddments bin, free to regular customers.

 

I remember from doing work in London that plumbers carry zero parts, and there seems to be a tiny merchant every few streets, selling pipe cut to length. Ditto electricians.