Plumber can't find leak

Joined
12 Oct 2022
Messages
28
Reaction score
0
Country
United Kingdom
Bit of a weird one, this. Pictures at end.

I woke up this morning to water coming down through the kitchen ceiling (and light fitting) and a pool of water on the kitchen floor. There's a bathroom above. I turned the water off and the water stopped leaking. I then rang a plumber who came to take a look. He couldn't find an obvious place for a leak. We turned the water back on, no leak even when he ran all taps/flushed the toilet.

He suggested it might be the soil stack, which is boxed into the corner of the room and runs down into the kitchen and up through the roof, but his company don't mess with those (said he'd send through the name of an insurance backed company that would do it). The reason he thought this was because there is a wet water stain running down the inside of the boxed in area. But essentially he shrugged and left. Water is still on. Still no leak.

What's going on here? How does a leak randomly spring up in the middle of the night, cause a load of damage, stop when the water is off and then not return when it's back on? I did ask him this and he said normally that happens when it rains the night before, but as there was no rain he had no idea.

Now I've got a theory, but I wanted to see if people thought it was insane or not:
1) The bathroom sink tap is one of those terrible waterfall taps. As with all (old) waterfall taps the screws under the spout have failed, so when you run it water leaks out the bottom of the spout and onto the sink-top. We were going to get this replaced soon, and ultimately the amount of water that leaks when you wash your hands/face was not enough to worry about immediately - i.e. you just wiped the few millilitres up and got on with your day.
2) The bathroom sink is built into the top of a cabinet. The cabinet is flanked on either side by worktops. The worktop was absolutely soaked this morning when we found the leak - there was a cloth bag on it and it was sodden. In fact, the reason my partner noticed there was a leak in the first place was her sleeve got really wet from the side - which is when she then went downstairs to look and saw the leak in the ceiling. She was in a panic - understandably - so can't really remember whether the tap was slightly on or not.

So is it possible it was just the tap being on all night, a slow leak over approx. 8 hours? The amount of water downstairs on the floor was probably around a pint I would guess, maybe a bit more. When I looked at floorboards under sink/bath there's water stains directly under the sink and then water stains that run along the floorboards towards, you guessed it, the boxed in area that contains the soil stack.

Appreciate this is a strange old post, but any thoughts welcomed. I am getting a different plumber to come tomorrow to see what he thinks as i really don't want to start hacking into the soil stack (which is boxed in in the corner of the bathroom/kitchen) unless it's really, really necessary. The fact there was water pooled on the worktop has to be explained somehow - it must have come from somewhere!!

Here are some pictures:

1 - https://ibb.co/vVr70PC - this is directly under the bathroom sink. please ignore the fact there are electrical wires everywhere, this was news to me and seems like utter madness and i will be getting someone to deal with them

2 - https://ibb.co/C1mYDgs - this is a view to the right of the sink towards the soil boxed in area with the soil stack and other pipes

3 - https://ibb.co/8jt0nf9 - the stains on the ceiling from the leak. the stains in the red circle are directly beneath the bathroom sink, the green circle is where the soil stack is boxed in, and the yellow circle is where other bits of floorboard were wet (but ultimately no pipes were found to be leaking there)

The final thing I would say is I was wondering about a leak for a few weeks now as there's been a slightly musty/hint of sewage smell in the bathroom. That smell seems to be emanating from the boxed in area, or perhaps under the floorboards, and the reason I say this is when I stick my head under the bath I get a waft from the void over on the right of image 2, and when the plumber was investigating he pulled out the downlight that leaked which you can see in image 3 and I can now smell that same bathroom/musty/very slight sewage smell in my kitchen. It's entirely possible the actual leak is the tap theory and this smell is something else, right? And if the smell is something else, what the hell is it???
 
Sponsored Links
Sponsored Links
okay, so it seems like my theory is correct.

This means that the weird sewer-y smell is unrelated, right? Do I need to get a drain survey to work out what's going on there?
 
I have one of those awful (Crosswater) waterfall taps. If the tap is left very slightly open, the water ignores the slight drip groove on the underside, runs down the body and some of the water runs over the side of the basin.
 
Cold water tank in the loft? During the day it keeps getting used so the level remains low, but over night a leaky ball valve let’s it fill up and overflow. Overflow pipe not connected or broken?
 
Cold water tank in the loft? During the day it keeps getting used so the level remains low, but over night a leaky ball valve let’s it fill up and overflow. Overflow pipe not connected or broken?
We have a combi boiler, but thanks for the suggestion


Second plumber came around, said the first plumber "lacked common sense" and said it probably was the tap as no other leak evident. He has now replaced that tap, so hopefully all sorted.

Still smells VERY damp though. How long does it take for that to die down?
 
We have a combi boiler, but thanks for the suggestion


Second plumber came around, said the first plumber "lacked common sense" and said it probably was the tap as no other leak evident. He has now replaced that tap, so hopefully all sorted.

Still smells VERY damp though. How long does it take for that to die down?

If the insulation is damp (between the plasterboard and floor above), it may take many weeks to dry out. Lifting some floor boards will help, as would cutting some holes in the ceiling.

At a push you could leave an air dehumidifier running constantly. Opening windows, will also help.
 
As above dehumidifier definitely needed and keep air moving.
The guys who do it all the time use large dehumidifiers with pumped drains so they run continuously and large fans to keep air moving.
Even a relatively small leak can take weeks to dry thoroughly.
 
I might buy a cheap borescope and take a look through ceiling below to see if any mould. Let's assume that I can see some mould, would it be crazy to spray mould remover (e.g. Zinsser product that you use pre-painting) into the ceiling void onto the mould? I really don't wanna start lifting floorboards (would have to remove the bath, most likely?) and cutting holes in the ceiling below is a bit of a no go as I am pretty sure the previous people who lived here skimmed over Artex that was put in the 1970s so might have asbestos in it
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top