Mystery leak (with pics). Toilet maybe?

[pb2012]

Hi all,

On Friday evening I spotted a damp patch on the ceiling where it meets an external wall. It hadn't rained for a few days before this. If it did, it was a a very light shower at worse.

Click the pics below:



Above that ceiling is an en-suite, with a toilet in the general location. The waste for the toilet is to the left of that red marker, in the chunky boxing.

I can't be certain, but I don't think heating or water pipes run across where the damp patch is.

I did notice that the toilet was making a constant dripping sound coming from inside the pan. Strange really. I flushed it and the dripping sound stopped.

Is it possible for a leak from the toilet to travel over to where the damp patch is somehow? E.g drop on to a beam and run along it maybe.

Thanks!

 

[pb2012]

A couple more pics to click. These show the toilet and damp spot positions from a couple of different areas.

 

[pb2012]

And finally, after a couple of days, the dark'ish staining has spread out a tiny bit horizontally, but receded back on the large areas. It is still damp to the touch, but seems to be drying out at the extreme edges.

 

[dilalio]

Path of least resistance would be to remove the toilet and get a torch in there to look for water trails to trace back to source of the leak. Fully remove all water from pan and cistern using a sponge, before doing this so that you don't create false evidence during removal.
Before doing this, you could remove all water from the cistern and pan (as described above and shove some newspaper in a plastic bag into the base of the pan to stop smells) then trace round the extent of the stain with a pencil and not use the ensuite for a few days... See if the stain retracts back from the pencil outline.
If it does you will know that it's either the flush from the cistern leaking (clean water) or pan con and waste pipework from the pan leaking (dirty water).
If the stain doesn't recede during this time then that points towards a supply pipe issue to either the cistern or basin or whatever other items are fed in the ensuite.

 

[rhinosaw]

Do u have a shower cubicle situated near to the toilet? They are often the culprit. If not
It may be easier to create a large hole in the box section and peer inside with torch

 

[pb2012]

@dilalio - thanks for the advice on how to go about it. That all sounds like a good plan to me. In your opinion/experience, can a damp patch like this be related to a toilet (or sink/shower etc) that is sited approx 700mm away on the floor above? I'm thinking a leak could travel along some timber and pool in a bit further down the way maybe?

@rhinosaw - There is a shower cubicle a bit further away yea, but it's actually never been used. It seems a less likely cause but you never know I suppose.

The damp patch doesn't seem to be getting visibly worse, but it's not really drying out either.

 

[undertrained]

I’d personally check the feed to the cistern first, and perhaps remove the top and check filling valve to see if it sprays onto screw holes, then as per dilalio.

 

[dilalio]

can a damp patch like this be related to a toilet (or sink/shower etc) that is sited approx 700mm away on the floor above? I'm thinking a leak could travel along some timber and pool in a bit further down the way maybe?

Yes. Definitely. Water usually travels across the back of plasterboard until it finds a joint where it then follows the joint. It'll then fill the joint (like a canal) and start to soak through and then blossom out on the skimmed side where the paper acts as blotting paper.

 

[pb2012]

Bit of an update on this. The damp patch hadn't worsened over the last few days, but it rained last night and the patch has now expanded.

It's either a coincidence somehow or the problem is with the roof. Agh! Nothing looks wrong from the outside, but it's a fairly inaccessible area (4 storey house) and hard to get up close to. A bigger problem than previously thought...

 

[ianmcd]

Check the window too it is common for rain to get in via windows