Water Stain On Kitchen Ceiling

[foxyferret]

A large water stain has appeared today on the kitchen ceiling. The kitchen is directly below the bathroom and the airing cupboard with cylinder. I took everything out of the airing cupboard and using a torch, had a good look under and around the cylinder but could not detect any damp. I checked in the bathroom but could find nothing, the shower/bath was not used last night so cannot see how water has come from there. I have a horrible feeling that it may be from a pipe under the floorboards in either the airing cupboard or bathroom and no doubt will have to get a plumber in. Is there anything else I can check or look at to try and find the source of the leak? Thanks for any advice

[KARL]

Assuming the stain is well defined so you can pick out a centre, if you can measure its precise location vis-a-vis a wall which you can then follow up onto the floor above and then transfer the location of the centre of the stain up there, then that is the best way to find where the leak is. However, water tends to flow/drain to the lowest point along the easiest path so even transferring the centre of the stain to the floor above can be misleading - really just a "best stab".

[The Builder]

Very difficult, foxy, as Karl has said.
Even if you do trace the likely source, you'll still have to deal with it.

In the "good old days", you just had to pull a couple of floorboards and investigate. Today though, bathrooms probably have chipboard floors and vinyl covering.
Worse still, tiles or hardwood flooring. Either way, investigation means a good deal of disruption to the bathroom. Re-laying vinyl, and all the rest.
Certainly have a plumber check it over first. Then, although you won't like this, my way would be to simply cut an inspection hole in the kitchen ceiling containing the stain.
The bigger "trapdoor" the better. Then you can get your head up there and shine a torch over most of the bathroom floor void, and probably find the leak. Leaking joints are quite easy to find then, and repair.

Believe me, it's a doddle to nail the same piece of plasterboard back up, and fill the saw-cuts. Even if you have to cut yet another access hole, it's still a much easier job than having to put the bathroom floor back together.

[KARL]

Builder is absolutely correct regarding the inspection hole(s), it's what I have done in the past. The measurement approach will initially give an indication as to possible/likely location, and without any disruption, but it will not be reliable.

[Ryzen]

Drill a small hole ..6mm..in the centre of the stain..and put a bowl under it..This will stop water build up and more damage..and you will find out if its a constant leak..say from a water pipe..or a intermittent leak from a waste pipe.

[bhg481]

Can I suggest before you start major work you check carefully any sealant around baths/showers etc. It's surprising how water can get past a sealant bead which has started to come away.

[alavahalf]

It doesn't sound like a leak from a water supply pipe otherwise it would be getting worse. To me it sounds as though it is from a waste pipe or trap.
One of the most common places for a leak in the bathroom, is often a waste coupling under the bath.
If I were you I would remove the bath panel if you can and have a look in there. Are there any overflows visible, check underneath them using a piece of tissue to detect and damp. As others have said .. silicone around joints often pulls away around baths and shower trays. Difficult to say without seeing it. Just poke a hole in the ceiling with a screwdriver at the centre of the patch or if the plasterboard is sagging, do it at the lowest point !

[foxyferret]

Thanks for all your helpful answers. The continuing saga. Water stopped coming through for about a day and overnight. Deliberately tried each bathroom fixture, watered around seals on bath, shower and washbasin but no water appeared through ceiling. Yesterday, put washing machine and dishwasher on (both cold fill)and while no water actually dripped, I could see a damp circle on top of the dried out original stain. I know I will have to get a plumber but I thought that was a bit strange.

[foxyferret]

We have cut a hole in the kitchen ceiling and found the leaking pipe. It is going up into the cylinder in the airing cupboard and appears to be leaking from a joint, it is all scaled up on the outside. We have a bucket now to catch the drips and the plumber is due at 3.00 pm today. If anyone has an idea of how much this should cost, I would be grateful for any advice.

[SparklyKid]

I would expect change out of £50.

[foxyferret]

Thank you sparkly

[foxyferret]

Just thought of another couple of quick questions. Should I turn the hot water off and will he have to drain the cylinder?