Damp Patch on External Wall

[Burnerman]

For your sake, I do hope you're right!
Can you be certain the header tank valve isn't passing at all?
It just seems to be a right coincidence, that's all. What other pipes could be down there?
John

 

[diynoob]

If I tie up the ballcock in the big tank the water meter stops.

So if its not the CH and not the cold mains then the only pipe in the kitchen that it can be is the pipe to the hot tap right?

 

[ree]

You have a leak in the concrete floor unless you can find otherwise.

Clean off the copper pipework and remove all surrounding debris. Now search for a weeping leak with dabs of tissue. If nothing found its most likely in the floor.

You show damp pics at the D/W, and C/H pipes - where are these locations on the kitchen pic- below the window?

You appear to have a cavity wall, so any leakage from the kit solid floor is passing thro the cavity - thro a bridged cavity or sodden cav insulation. Plus, no solid floor membrane (DPM) is visible in the pics.

Perhaps, as someone suggested, remove a couple of bricks and investigate.

 

[diynoob]

Hi, yes the leak must be in the concrete but I've been trying to figure out which pipe it is first as its an expensive kitchen to rip out and only 12 months old.

The kitchen company have agreed to come and have a look. I'm pretty sure this only started after they fitted the kitchen.

If it is the pipe to the hot tap, its the one on the left here which goes into the concrete (as does the cold pipe and CH pipes)

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• diynoob
• 9 Mar 2015
• 1

I've circled in red where is is when viewed from the outside:

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• diynoob
• 9 Mar 2015
• 1

 

[ree]

I dont understand you:

If both Cu pipes go into the concrete at the same place then you dig out from that same place. Are we talking about one place where two cu pipes enter into the concrete or two different places?

Whether the pipes are hot, cold domestic or C/H is irrelevant - you are looking for a leak in copper pipe(s), thats all the info needed.

Which still leaves open the question why are two damp patches showing on the surface a little distance from each other?

AAMOI: the soldered fittings in todays pic looked to have been burned in - not a reassuring sign.
A sign of a good job is when the hidden areas are left clean and well clipped. Cables left lying on hot pipes is amateurish and possibly dangerous.
Unclipped pipes can rattle and sometimes leak, esp near apps.

 

[diynoob]

Yes it's 2 different places. The hot and cold water pipes in the picture above are under the sink and surrounded by unfinished surfaces. So if that is the root cause I have some hope it can be investigated without wrecking the kitchen.

The point where the CH pipes enter the concrete is several feet away and right next to the tiled floor which I'd rather not take up. My belief is that taking up the previous floor is what damaged the pipes in the first place.

I am also confused by the damp patches. My guess is that it has seeped upwards from a leak in the concrete in various spots where the water has found less resistance to leak in that direction for one reason or another.

 

[Burnerman]

If I tie up the ballcock in the big tank the water meter stops.

So if its not the CH and not the cold mains then the only pipe in the kitchen that it can be is the pipe to the hot tap right?

Hang on mate, it's the smaller of the two tanks that need checking .....the big one is for the domestic hot supply.
John

 

[diynoob]

Yep stopping the small tank makes no difference, so the leak is not on the CH pipework.

If I tie up the ballcock in the big tank the water meter stops, so the problem is with the HW pipework.

 

[Burnerman]

Aye, fair do's.
Can you pull one unit out, maybe leaving the work top on just to do a little excavating?
This must be no fun at all
John

 

[diynoob]

Yeah definitely not fun Burnerman. The pipework pictures are taken by peeking under the plinths and would be a real pain to get to, to start excavating. The units under the sink should come out I think and more to the point if the problem is under there, then it's almost certainly been caused by the kitchen company.

The reason I dont want it to be the CH is firstly because the kitchen fitters didnt touch the CH so likely not their fault. Also, the CH pipes are under the units in the foreground below. It's a 4 man job just to lift off the granite worktop so not DIYable!

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• diynoob
• 9 Mar 2015
• 1

 

[Burnerman]

I can only suggest - rightly or wrongly - if the fault was caused by the fitters then hopefully the damaged pipe won't be buried too deep .....fingers crossed!
Could there be any possibility of the kitchen drains leaking?
That's a beautiful kitchen you have there.
John

 

[ree]

"taking up the previous floor is what damaged the pipes in the first place" - What do you mean? Who took up what, and when was it taken up, and what for?

If pipework is going into a concrete floor, modern practice for water pipework is for continuous lengths of plastic pipe to be set in channels or conduits.

Presumably, allowance was made for removing the apps and base units without disturbing the work top - nowadays, its sometimes the case that householders wish to change arrangements at a later date.
Hence, you could pull units to gain access to the unfinished floor below them ?

FWIW:
1. If all else failed, you could abandon all pipework in the kitchen floor and thread plastic feeds, and supplies to wherever, below the units.

2. Its a simple matter for a plumber to test the soil pipe for leakage if a manhole is available.

 

[diynoob]

The kitchen was completely refurbished in 2013, see previous pictures. It ws done by a local kitchen company. It took 2 men 3 days to get to old floor tiles up using heavy machinery so that is what I think caused this.

There's no way the copper pipes are in conduits or channels. The pipework is from 1982.

@Burnerman Hopefully the damage is near the surface as you say.

@ree If the leak cannot be found then yeah you may be right I could abandon the damaged pipe and have a new one run.