Leak? Where from?

[TheOpalFox]

Is this a leak from the bathroom or not please
my bathroom isn’t above it tho. This mark is in my living room?

Depends. Do any waste water or is it just heating pipes that run under the floorboards in the room above? Does the patch get bigger when someone has a shower or runs the bathroom sink?

Can be difficult to find the source of leaks because water ‘finds a way’. Where is the bathroom - not above, but near? As PP said is it worse/obviously more damp at certain times? Are there heating pipes under that floor above? Is there a downpipe on the wall/s nearest to that corner?

Do you have a smart meter? When I switched to one, it straightaway detected a major leak which we were able to fix?

Water doesn’t always drip directly down, it sometimes drips onto a pipe or board and travels a bit before it drips more. You’ll need to open it up and find out. It could even be from the roof, gutters or window.

You may want to tag Pigletjohn….

It's a leak (unless you have a dead animal rotting above the ceiling)

Your photo seems to show a water pipe rising up the wall at the back pretty much in line with the leak.

My first guess would be that pipe goes up and then tracks along the ceiling towards you. Tiny hole or a solder joint slightly cracked.

Either way you need to look under the floorboards from the room above which will let you see if the leak is there or whether water is getting there from somewhere else.