[cybernaut]

I've had this problem twice, once in the kitchen, once in the bathroom. After finding the causes, I conclude it is impossible for water to seep up tiles.

It's not coming from pipes because they are installed on the perimeter of the house. So how does water wind up in the grout often far removed from any water source? In my case, the refrigerator happened to have an water pan on the bottom that I was unaware of. It was overflowing. Water from the pan dripped down the tile, finding the lowest point, which was the grout. It then trough-ed down the grout to the lowest point of the floor where it collected in the pool, surrounded by damp tentacles. By the time I would see it, the source where it dripped from had long since evaporated, leaving only the pool at the lowest point of the floor. The damp tentacles may give a clue as to where the water came from. The point is the water you see is almost never where it dripped originally from. It gives the illusion of seeping above the tile, when in reality just the opposite is true: the grout is containing the pool of water because the grout is not porous. So don't go busting up those tiles! The problem is more innocuous than you think.

[speedball1]

Hi cybernaut and welcome to The Plumbing Page at AskMeHelpDesk.com You are responding to a 4 year old dead thread so I gave you one of your own. Please check the date before you post. Thanks,
And thanks for the update and explanation, Mystery solved! Who would have thought? Cheers, Tom