Plumbing problem with own home...Mystery Water Problem

Good morning,

Yesterday, as my wife was so kind to let me sleep in for once, I was awoken anyhow by a couple of gallons of water coming through my first floor ceiling into my family room.

My two smallest were play with a few toys made for water in about 4 - 5 inches of water in the bathtub above. They are nothing more than a few little race cars that change color when put in cold water.

When they were done playing, my wife went up there and drained the tub. Within a half hour she noticed water dripping from the ceiling directly below the bath tub that soon migrated across the entire ceiling.

Here is the kicker, after turning off all the water and draining the lines, I pulled a small section of the ceiling out to get a look up in the ceiling where the damage started. About 2 gallons of water came out. After drying out a bit I could not find any burst pipes or damage anywhere. My first instinct was that this might be from a frozen pipe, because this plumbing is only a foot from an outside wall and the temps here in the northeast lately have been in the teens at night.

Next, I decided to try and turn the water supply back on slowly to see if I could pinpoint a leak. NOTHING LEAKED. Therefore, I tried filling the tub and draining slowly. Still NOTHING. I had a contractor come over and he could not find a leak either. The drains have been clear and are still clear. His only guess as to how all of this water may of ended up coming through the ceiling is that there could have been enough of a clog above the P-trap where the tub drain comes into the line that might have caused an uplift in the draining and it perhaps came down around a bad seal at the drain stopper level.

Any and all ideas/suggestions would be greatly appreciated.


Steve :neutral:

Any way of checking the over flow drain
Ps when our kids took bath with toys it look looked like marine world maybe it was splashed over the sides.

If the the tub is older, when you put extra weight in it such as kid’s playing around and jumping up and down in the tub or adult standing in it. It flexes at the drain basket and allows water to flow under the lip.


As we all know, the leak may not be where we notice that it “appears” to be leaking from.

What about the wax ring at the WC???

Any chance of ice buildup at the exterior wall that melted when the kids had their hot bath? (I know you stated 2 gallons worth, but was it really? A small amount looks like a lot more, when you’re not expecting it).




Thanks for the great inputs. I’m going to try and quickly address some of the things that were brought up. I’ll try and post pics tonight when I get off work. I work for and aviation company during the day…

Wayne - good point, I think I’ll try and test that overflow drain when I get home this evening, that might verify the original theory of the contractor that came to my house.

Gerry - There was only 4 to 5 inches of water in the tub at the most. The only thing in the tub was a few plastic toys the kids were playing with while sitting in the floor on the outside the tub. They weren’t actually taking a bath. Age of the tub is 11 years.

Jeffrey - The only place that was wet this far up into the walls above was right at the tub. The insulation I pulled out was soaked up to the point vertically where the overflow drain is located. Everything else was dry (except the track across the ceiling) as far as insulation goes beyond 2 feet of the tub. Also, none of this happened until 30 minutes after the tub was drained. I’ve since turned all water on, flushed all toilets, filled tub up and drained again, ran water in sinks, etc… everything is still dry. I still have the buckets of water that we managed to collect. I would estimate at the least 2 gallons + what is soaked into the insulation I pulled out…


Steve :shock:


Is there a washing machine on the other side of the tub wall or on the same level of the home?


Nothing on the other side of the wall or withing 6 feet of the damaged area.



It can’t be the overflow piping, this drains into the same waste pipe below it.

Unless it is cracked or broken where you can’t see it, before it gets to the waste pipe…

Is it a fiberglass tub unit?

More than likely it is leaking around the drain when pressure is put on it. Our shower is torn apart while we wait for a new drain to arrive.

That pipe could be cracked, I’ll get a closer look this evening. I don’t think the tub is cracked because there was no one in it when this happened or prior to. We’ve since filled it up a few times and no leaks appear. If not the over flow pipe, my guess is the seal against the tub where it connects. I’ll be sure to come back and post whatever I find. Thanks again for all the ideas.



My kids had water running out of our HVAC duct one “bath time”. They splashed so much water on the floor that it was running into the floor vent, and draining out another in the basement. When we discovered the problem, and went to check out what they were doing, they had about an eighth inch of water on the bathroom floor, and more adding all the time. Could be they just made a huge mess. Check all the floor vents, and also the caulking around the tub, and the grout at the tiles.

there does seem to be a direct correlation between kids playing and water leaks through ceilings below bathrooms…I stopped being amazed by this long ago …

Check the shower head connection in the wall. Ask the kids if they turned on the shower while they were playing.

Got home this evening and with some assistance, took a pitcher of water and poured directly into the tub drain lever area. Watching from the other side of the wall through an access panel (I just installed) I immediately saw where water was getting through the drain pipe. I found the attached diagram of a tub drain and marked it up in MS Paint to show where the water was coming through. Makes sense now because all of the wet fiberglass insulation was at this point and below.

I started searching the web to see if anyone had ever experience a similar problem with a P-trap freezing and water backing up a drain and found quite a few.

Tub drain link.jpg


There should be thick gasket between the tub and the overflow flange where it is leaking.

See if you can tighten the two screws and tell your kids not to fill the tub so full. :wink:

I was close

Had that issue here at my house recently. Turns out there was avery small gap between the spout and the tub. Water was leaking down along the length of drain line until it reached the ductwork and came out a register. Caulked around the spout and problem solved(until the kids stand on it). If you had the presence of mind to observe if the water was fresh or soapy that might help point in the right direction.

New gasket and keep the cover tight. I check these whenever possible on inspections. As you discovered in your test, the water level does not need to rise above the overflow for them to leak. Showers or kids hands at the tub spout are capable of causing a decent amount of splash around the cover. If the gasket is mispositioned, dried out or not held tight by the cover screws it will leak.

Nice find…

Weren’t those small lower holes being utilized?

Those are used to secure a temporary U-shaped support bracket which braces the head fitting against the tub end wall while the leak test is performed and before the finish cover plate is secured to the head fitting.

Here’s a better image…