we did initailly think it could be Mouse pee - but the patchs are to big - unless the mouse is a real drinker!
If I can avoid don't really want to replace the boards but it is looking like the only option.
We have recently moved in to a 1920's terrace, there are 3 small damp looking patches on the floorboards in the downstairs rooms. when you touch them residue is left on your fingers. So I though may be rot or damp.
I took a floorboard up to have a look underneath and the underneath surface of...