Urine Leaking from UNDERNEATH Toilet into Ceiling Below - NOTHING above leaking!

We just installed the toilet. There is UNDILUTED urine leaking down, but only from below the toilet (nothing showing around the bowl near the toilet or where the toilet meets the tile on the floor). You can only see the dripping urine from the basement, when you look up near where the toilet seal is. There is NO urine showing anywhere above.

It appears to be dripping down from near the seal, over the cast iron pipe that connects to the bottom of the toilet (1940's house). The odd thing: When you flush the toilet, it doesn't drip. We haven't figured out when it drips, but are thinking it must be when someone urinates in a certain way INSIDE the toilet ! Again, there are no signs of urine anywhere outside the toilet or around the base near the tile in the bath. The only thing we see is the urine, every now and then, dripping from somewhere around the bottom of the toilet, onto the cast iron pipe that takes the waste away in the basement.

could this be a crack somewhere in the toilet itself since the urine only appears intermittently; is NOT diluted with water; and is not showing up anywhere in the bathroom near or around the toilet, but is only showing up BELOW the toilet, in the basement ceiling below? we are thinking perhaps a boy is urinating and hitting the toilet at a certain spot which is causing this intermittent leak.

Any ideas?

Hmmm, well one of two things, either you have a crack or that little boy is peeing all over the place. Probably peeing around the toilet seat bolts and it's running down the bolts and dripping onto the flange bolts holes. You basically have to troubleshoot the problem starting with the most obvious and go through a simple process of elimination (no pun intended). You have a few ways in which undiluted urine could drip through the floor close to the seal,
1. No caulking between toilet and floor
2. No bolt caps or no sealing of bolt caps (I put a little silicone on them to make it easier to clean)
3. Crack in toilet
4. Boy peeing in area of bathroom other than IN the toilet, this could be a corner or just straight on the floor.

If all else fails, get a bottle that has a pull up cap like your dishwashing liquid bottle, fill it with water and put a little bit of food coloring in it then start your own tinkle party with the toilet, squirting water here and there and all around and see if you can pin point where it is. Good Luck!

This is almost certainly due to two situations. First, when the toilet was installed, it was not caulked around the bottom edge. Second, you have males in you house with poor aim. They are urinating on the front of the toilet and it is running down and getting under the toilet. Even if the bowl had a crack, it would leak mostly water, not straight urine.

Often, it's a dog or cat that decides since you do it, they should do it there as well! Or, a little boy with poor aim. To prevent it from getting under the toilet, many places require that you install caulk around the base of the toilet. One that works well, and doesn't glue the toilet to the floor for later maintenance or replacement, is PolySeamSeal.

It is very rare to have what you describe as undiluted urine leak from any part of the plumbing system. It gets diluted as soon as it hits the bowl!

In my experience, I have had numerous calls about urine leak/smell in a bathroom. EVERY SINGLE ONE turned out to be a young lad, careless teenagers, and mainly older gents. I even had one old guy, who for his age was in great shape...he just didn't like to turn the light on at night!

I am open to hearing from the other guys if there is a better possibiltiy for you to investigate.....

THANK YOU ALL!

I read up on this before and think the same thing -- bad aim. the urine is DEFINITELY undiluted, though (it falls into a bucket), and it is intermittent and sparse (tablespoon every other day or so). The twist is that the urine is NOT ending up OUTSIDE the toilet. there are no stains or smells or anything upstairs or around the toilet EXCEPT on the back (very slight, minuscule) where the toilet seat connects to the top, back of the toilet. there is caulking around the base (i did it), so the only thing I can figure out is that it is bad aim, but wherever that aim is hitting appears to be falling directly into the basement. I will have a detailed discussion with the 9 year old (only possible culprit), but am wondering if the could urine be leaking through the bolts that connect the toilet seat? or perhaps he is peeing close to some other connection inside the toilet? again, no stains on the bottom where the toilet meets the floor, so appears to be leaking somewhere else!

I had an older customers once that used to turn the lights out while I was working.
He used to pee on the floor, and then would call me over for a service call.
On one visit, I mentioned that his upstairs toilets was leaking. It was on old one-piece from the 60's.
I could hear the leak from the kitchen. They couldn't hear the leak standing in the bathroom.

Turns out it was NOT bad aim, but the joint between the cast iron pipe running waste water from the toilet, into another cast iron pipe has a very small leak (lots of rust, so it looked like urine, but was not). House (and thus cast iron pipes) is 71 years old. Going to try plumbers epoxy and see what happens.

Good job on your persistence in tracking this down. We would fix the joint, but I believe you can do an adequate repair with Billy Mays' special stuff. Just keep an eye on it from time to time.