How can I locate and repair a leak?

Question

We recently bought a 100 year old house that stood uninhabited for 18 months prior to our move. Everything had been properly winterized for the cold winter months (Temperatures can reach -40 C) and the water was turned on and seemed to be working properly for about 3 weeks. Then we ran into some issues. The house is two storeys with two full baths on each level stacked on top of one another. The first floor toilet had a minor leak that seemed to correct itself within a day and hasn't been an issue since. The second story toilet began to leak about a week later due to the tank overfilling and leaking through the flush handle. We remedied this problem quite easily and the toilet hasn't leaked since. Now here comes the real issue.

Shortly after the second toilet leak, we woke up early one morning to discover water covering the floor of the first floor bathroom. It was coming from the ceiling at a steady drip rate, but nothing alarming. We shut the water off to the entire house and the dripping stopped after about 12 hours. During the following week we ended up peeling back the plastered layer on the ceiling to discover that it is made of cement board (??) and the water seems to just seep through when the water is on. We can access the shower pipes on the second floor through a removable panel in the wall, but there is no water to be seen. I guess I'm just trying to see if anyone has had experience with a similar issue, any suggestions as to how it can be diagnosed/fixed, and whether or not I'm going to have to take a second mortgage out to fix the issue.

I should mention that we did call a plumber the same day the ceiling leak was discovered. He set up an appointment, but then called back and told us that if the leak was related to a burst pipe, the amount of water leaking would be much more substantial and it wouldn't continue to leak after the water was turned off (which it did initially for about 12 hours). He informed us it was probably water that had pooled underneath the upstairs toilet and was now seeping through the cement board. We now know that the leak will start and stop in relation to the water being turned on and off, but I think the issue is that the leak isn't a dramatic one when the water is left on. It just kind of... drips through. Please help!

Answer 1

What this could be is that you have a slow leak from the floor above. Probably a water feed rather than a drain. Although it could be from the heating system if you have a water or steam system with radiators. When you turned the water on the house it started to drip, and the ceiling soaked it all up. Eventually the ceiling became saturated and started to drip onto the floor.

If you do have a slow leak then obviously you need to find the source. It's probably a leaky pipe joint, or maybe a loose compression fitting. The only way you're going to find it is to get access, as for how that completely depends on your house's construction. There may be a panel in front of the bath that can be removed, etc.

What you need to do is meticulously go through the whole bathroom above and look for any kind of access to pipes you see, and look for signs of dripping moisture, oxidation on the pipes, or hard water deposits. As it sounds like the whole ceiling needs to come down on the floor below do that first, then use that access to find your leak.

As for how to fix it if it's a compression fitting get out your wrench and have at it. If it's a solder joint or a bad pipe get a plumber in unless you have the tools and the experience. Good luck!

Answer 2

You may want to thoroughly check around the upstairs toilet stool and tank. You already mentioned that there was a leak there that was easy to correct..............but maybe your fix was not a 100% solution. Wipe down all visible pipes and joints with paper towels. Then wrap the joints with new dry towels and let them stay in place for a few hours. (You can use a short strip of masking tape around the paper towels to help hold them in place). Later go check all of these and see if any show any signs of wetness or damp. If so there is a leak nearby.

Keep your ears open to unexpected re-filling of the toilet tanks. If this happens there may be a slow leak in the toilet tank system that is dripping someplace other than into the drain system.

Answer 3

The basin and shower share the same pipe that attaches to the waste water down pipe. The connection between the waste down pipe and the basin/bath/shower pipe may have a leak. If so the water usually will flow down the outside of the waste water pipe and appear on a lower floor.

Answer 4

I once had a similar situation where an upstairs toilet had an un-noticed pinhole leak in the supply line that runs from the valve on the wall to the bottom of the fill valve. The leak wasn't discovered until the wall down stairs had been ripped up searching for the source of the water. A tiny leak, not a drip but a little spray, over the course of a couple of days it caused quite a mess.

These supply lines can get very fragile over time and any disturbance can cause small holes or cracks.