Random damp patch

[N3mo]

Normal central heating run off a combi. Nothing directly above and no leaks upstairs. Noone has interfered with the floors or anything. Hence why am baffled

 

[CBW]

I know you said heating is fine, however have you checked that rad/pipework for leaks? Does boiler lose pressure?

 

[JohnD]

do you mean the water supply pipe enters the property from the rear? Pipe comes from the back garden? Not from the road at the front?

What route does the pipe then take to the bathroom and/or loft?

Have you examined the floor on both sides of that wall? Is it dry?

Can we have a photo of the other side please.

Do you mean "yes, yes, and no" to my first three questions?

As you will have noticed, we suspect a plumbing leak, and are trying to work out what sort, and where it comes from.