Noticed a leak THIS close to Christmas. Help!

[namechange246810]

Just noticed this in the downstairs WC. The room was freshly painted last year so paintwork is relatively new. Not sure how long the stain has been there- so annoyed! Any ideas on the best thing to do next? Plumber? Any ideas of costs involved? Ahhhh!

Is the ceiling damp or wet where the stain is OP?

Yes, slightly damp.

I agree with others that the outside wall looks really iffy. Could be as easy as fixing the pointing on that. Could be water leaking around the bath sealant or some failed grout when you shower. Could be a leaky pipe under the bath. It's easy to take the bath panel off and have a look. Check all the joints in the pipes with dry tissue first. Then check again after running the shower. If no leaks appear then get the outside wall fixed - well, get that fixed anyway. If a leak appears then you either need a plumber to repair the leaky joint or you need to regrout or re do your sealant. The most expensive thing will probably be the outside wall.

It could simply be the sealant between the Bath taps and wall. Even a tiny gap as you shower could cause that. You can reseal it yourself v easily

I guess the immediate issue us now f8xed - but all the same, am sorry OP, but your external wall looks like it's v wet. I would get the brickwork sorted, and check the pipes leading to the soil stack, even if that's not the source of the damp ceiling.