We have a dark line on the floor, it is 1" to 4' in places.
It starts under our master bedroom door and goes into the kitchen. We think it is water. Sometimes it is darker and wider in places than at other times. We are on a cement slab with hardwood put directly on top. We have looked everywhere for water leaks. The closest sinks and bathroom (mbath) is in the room next door but there is no sign of water there on the floor. We have turned everythin off in that bathroom and not used it for a week but it does not appear to change the line on the floor. The water meter does not move at all so whatever it is is very slow. It has been like this getting steadily worse for the past 2 months.
Does anyone have any ideas. We are hoping not to have to pull up the hardwood floor.