An unexplained plumbing mystery

[American Horse]

Just before 2PM today, I was walking the short distance from my den/office to the kitchen and stepped into a pool of water about the size a half-gallon of spilled water would make.

I backtracked a few feet to the bathroom, and there was nothing overrunning or leaking there.

Stepping over the water in the small hall and into the kitchen, the water seemed to have started around one corner of the refrigerator, which is next to the dishwasher, which is next to the kitchen sink. There was no pooling or overflow in either of those, so I zeroed in on something leaking from the frig, although both the main unit as well as the freezer were both running at normal temperature levels.

So I called the maintenance man, who pulled out the frig. Again, no water beneath the frig. He even unscrewed the entire backing and again could find no leak.

Nothing was leaking from the ceiling, and no water coming up through the floor. It hadn't rained since yesterday (and I would have noticed before now, if it had been caused by rain).

We're both stumped.

I'm curious if anyone here has any building construction or plumbing experience that might explain this phenomena. Without one, I have to conclude that I have a friendly ghost who likes to play tricks.

Is there a shower or a tub/shower on the other side of the wall from the fridge?

Nope.

An intermittent leak like the one which you describe often has to do with a valve. A dishwasher, ejects water from the bottom well when it first starts up; a shower valve may not be used often when there is a bathtub and a person prefers a soak, but when it's used it may leak water into a wall cavity which will flow out onto a floor; an outside freezeproof faucet may have frozen during the winter, and water is injected into a wall cavity when someone turns it on outside to get water from a hose; a waste vent in an attic might become seperated from winter truss-lift, and water then drain from a sag in the line flowing into a wall cavity and out onto the floor.

You said "up through the floor" - Is it a concrete floor?

If I were investigating, and it wasn't a concrete floor, I would go into the crawlspace and see what signs were there which would show intermittancy and extent, as well as more precisely the source. If nothing there I would go into the attic and see if something came loose up there, if there was no other obvious source.

A few days ago some people who depend on me for troubleshooting things like this called with a large amount of water soaking their carpet in a closet. On inspection of the attic there was a small roof leak (from a ridge vent) but only a drip a few hours after rain. I went into the crawlspace and isolated the source. A screw in plug in the shower valve had given up mass from electrolisis creating a small hole in the plug which only leaked when the shower was turned on spraying water into the wall cavity, then leaking out onto the floor from behind the drywall.

A troubleshooter worth his salt would find the problem, and make very few guesses.