Pinhole leak repair in hard to access pipe

neilmcl

My dad discovered a leak coming from behind a boarded out area of the kitchen and after removing the boards we discovered the leak is coming from a pinhole leak in a hot water pipe. Unfortunately the pipe is very close to the wall and the leak is coming from the backside of the pipe. There's probably about 3mm between the pipe and the wall.

Any recommendations of which is the best way to repair it.

neilmcl

We have been looking at using one of these Flowflex copper repair patches.

https://www.screwfix.com/p/flowflex-clickfix-copper-pipe-repair-patch-15mm/5962v

stuart45

I'd knock the brickwork out for access , but as a bricklayer it's an easy repair for me. There's probably an easier way.

theoretica

I would clean the pipe and wrap it in silicone repair tape while considering a more permanent repair.

Jeepers_Creepers

Hi Neil.

What's the cause of the leak - just that a 'pinhole' has appeared, or was there a physical impact? If the former, then surely there's a good chance the whole pipe is dodgy?

There was some really poor quality copper used for pipes at some stage - '70s, '80s? Can't remember, but if you are in a soft water area, there's a chance it's natural corrosion from within.

Where does that pipe go when it disappears through the wall?

neilmcl

Jeepers_Creepers said:

Hi Neil.

What's the cause of the leak - just that a 'pinhole' has appeared, or was there a physical impact? If the former, then surely there's a good chance the whole pipe is dodgy?

There was some really poor quality copper used for pipes at some stage - '70s, '80s? Can't remember, but if you are in a soft water area, there's a chance it's natural corrosion from within.

Where does that pipe go when it disappears through the wall?

No impact, just suddenly came on, so must be corrosion of sorts. Agreed, the whole pipe could do with replacing but it runs down the wall and under the kitchen floor, which is tiled. The kitchen is at a lower level than the rest of the house so on the other side of the wall is a small crawl space, the pipe runs along there to the far side then upstairs to the bathroom.

We're going to try cleaning and patching the pipe tomorrow and if that doesn't work he'll get a plumber in to sort it, who will no doubt cut out and replace some of the pipe. Not sure how they'll cut it given you can't get a normal pipe cutter behind the pipe.

Jeepers_Creepers

Always the case, eh! Really awkward.

The solder-repair you linked to is good, I believe, but you'll need to get the pipe nicely clean (easy - some 240-grit paper slid behind the pipe, held at both ends and 'towelled' clean), but the pipe will also need to be empty of water...

Don't worry about how a plumber will cut the pipe - they'll have X methods

neilmcl

I "think" we'll be able to drain the pipe enough. There's an unused washing machine hot water feed that's lower than the leak so hopefully opening that should drain enough water out.

Grenage

If there wasn't enough room for a hacksaw or rotary cutter then I'd also knock a brick out to cut and solder a repair.

The seemingly drastic routes are usually quicker than trying to be clever.

Jeepers_Creepers

A multitool would soon cut out whatever section of pipe is needed. A couple of slip couplings (pre-soldered) would take care of fitting the replacement pipe. https://www.wickes.co.uk/Primaflow-Copper-Solder-Ring-Slip-Coupling---22mm/p/195177

Like falling off t'horse for a plumber. And DIYable for many folk too.

I personally wouldn't cut/bolster/remove any bricks - I just don't see it's needed.

A hacksaw would do this too, in a padsaw handle. Gentle cutting pressure, with plenty long cutting strokes.

tacpot12

I carry some some rubber discs (tap washers with no holes) and a couple of jubilee clips for exactly this sort of situation.  You can open the clips up to get them behind the pipe; you only need 3mm. They are only a temporary repair. I think that the entire pipe should be replaced as it could be about to fail in other areas.