I don't have plans for the house. I have had a plumber here but he's dug and he didn't find the pipes. We have had every kind leak imaginable for months. Now it's coming in under the concrete and water is getting worse.

Could someone please help me to know how to find the sewer pipes?

  • Hello, and welcome to Home Improvement. We'll need more info to help you. For instance, where in your foundation do our internal pipes lead out, and is there somewhere on the street where they're headed? Pictures or a diagram would also be helpful. – Daniel Griscom Feb 2 at 20:38
  • You live in an 'underground house' or you have a basement that is below ground? Where is this located? In the US, for a home built at that time, you should have at lease one of what is called a 'vent stack' that is a large cast-iron pipe running vertically into the slab (basement floor). This is connected to the sanitary sewer. – JimmyJames Feb 4 at 18:18

On homes that have sewer under the slab I have rented a tracer and purchased a tracker ball I flush the ball (I have attached fishing line to the ball to controll how far it goes) I then use the tracker to figure which way the pipes go. Once I get the general direction I will release some line and flush again, tracing where the ball goes until it quits moving. I have found septic tanks using this method that were more than 100' away from where it was shown on the plot plan. Several times I was able to retrieve the ball but I have also lost a few they are designed to be flushed I just hate dumping 20-30$ down the drain (pun intended). My local equipment rental place rents the receiver but you have to purchase the balls and once activated some only have several hours useful life. I have cleaned a few up and opened them and pulled the battery and was able to reuse but some are sealed so well it damages them beyond use. This is the method I have used to figure out where the plumbing goes and also find a tank that was not where the plans showed. At the age of your home this method could save a lot of time and expense as you will be able to cut a trench above the pipe to allow for replacement as it sounds like your pipe may be leaking, the only way to stop the leaks cost effectively is to replace the old cast iron pipe with plastic.


There are several issues: 1) sanitary sewer leak, 2) storm sewer leak, 3) watertable issue, 4) sewer pump

First, I’d confirm WHEN it leaks. You’ll need to confirm if it leaks ONLY when you flush the toilet, take a shower, empty the kitchen sink, etc. ...OR... does it leak after a storm, etc.? These are separate pipes with separate issues.

Second, I’d confirm the house has not “moved” (settle) because an underground house has some unique stresses on it and cracks and leaks are early signs of trouble.

1) All plumbing fixtures are suppose to be connected to the sanitary sewer line. You can verify if it’s leaking by flushing dye through the pipes from various locations.

2) To locate storm water leaks, we don’t use dye because it can get messy. Rather, we turn garden hose on and try to make various items leak. You don’t have gutters (underground house) but you could flush catch basins, interior floor drains, etc.

3) I’d keep a journal and make notes as to when the leaks occur and when it’s worse. Subterranean water can rise up during heavy rains. If this occurs, perimeter drains will need to be installed to lower the water table.

4) I’d check to see if your house has a sewer pump. If you are located below the road, then you’re probably below the city’s sewer system (pipes) too.

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