Sewer leaking under basement floor | White Paper

Sewer leaking under basement floor

A white paper on broken sewers beneath basement slabs


The Situation

Your basement is filled with nasty smelly odors and you don’t know why.  Every time you flush your toilet, take a shower, or do laundry, your basement just gets more stinky and damp.  If this is happening in your home, there is a good chance that a sewer pipe is leaking somewhere under your basement floor.  Fixing such a problem used to be difficult, destructive, and expensive. It doesn’t have to be. Plumbers today have the technology to pinpoint the exact location of a  problem, and repair it with little to no destruction to your property. This white paper showcases some methods C.A. Taciak and Sons uses to repair and replace sewer line pipes under a basement floor.

The Background

Sewer leaks under a basement floor often appear in homes built before the late 1970s.  This is due to a characteristic of a material found in older plumbing systems; cast iron.  Cast iron piping was the most common form of drainage piping until the invention of PVC plastic pipe. Older homes almost always have cast iron pipe installed beneath their basement floor.  In most situations, cast iron pipe is very durable and long lasting. Cast iron is still a common plumbing material today. In fact, many older homes in the Baltimore area have cast iron piping under their basement floors that have no problems now, and won’t for many years.  

However, a cast iron pipe will develop problems if installed improperly or in hostile conditions.  Two common causes of cast iron pipe problems are level piping and excess groundwater. Cast iron pipe will reliably convey water for many decades but it was never designed to hold water.  If a pipe sits level, it does not drain correctly and will allow water to sit inside it.   Water sitting at the bottom of a cast iron pipe for too long will begin to rot the pipe from the inside out.  Conversely, if a cast iron pipe is subjected to excess groundwater, it can rot from the outside in. You can see how this might cause problems if this pipe is buried under a basement floor.

The Problem

Plumbing leaks above ground are obvious.   If a pipe starts dripping in a wall or a ceiling, a wet spot always shows up nearby.  However, when a leak starts under a concrete slab, it can appear far away from where the problem is.  Usually, leaks under a basement floor appear as smelly water in your sump pump pit. This happens because the water that you use in your toilet, showers, and laundry, leaks out of the sewer line and through the dirt underneath your basement floor, and flows to any open access point.  Unfortunately, this also means that the sewer leak could be almost anywhere under your basement floor.

In the past, many plumbers addressed this problem by simply breaking up the basement floor from one end of the building to the other in order to replace the entire buildings sewer drain pipe.  Without knowing exactly where the problem was, replacing everything was a safer choice. This style of repair caused lots of problems in finished basements. No one enjoys replacing an entire tile floor to fix one inconvenient plumbing problem. 

The Solution

The key to solving sewer leaks under a basement floor is an accurate diagnosis.  A thorough sewer camera examination of the drain piping under the floor is absolutely necessary.  This analysis will not only show the condition of the pipe but also the specific locations of any problems.  During this examination, water should be run through the pipe. Any level areas that do not drain well will be located and noted.  Once those areas are clearly defined, problems such as holes and leaks can be determined.

Once all problem areas are identified, a plan of attack can be created.  It is rare to have to excavate an entire basement floor if the piping problem can be clearly diagnosed.  In most cases, issues can be isolated to one bad section of pipe, or even one connection between two sections of pipe.

In some cases, a repair of a sewer leak under a basement floor will involve excavation.  Due to the nature of the problem, there may not be any other alternative. In most cases though, we are able to install a permanent surgical pipe patch repair to the problem area without any digging or destruction.  Pipe patch is a lot like a stent for a heart problem. Pipe patch requires only a small clean-out size access to the sewer line for installation. An extremely durable patch is pushed into the pipe and installed over the problem area.  This patch is significantly stronger than the existing pipe and is rated to withstand much more abuse than any other comparable plumbing piping. You can rest assured that once the patch is installed, you won’t face that same problem again.

Lets Get Started!

If you think that you have a sewer line leak under your basement floor and would like to talk to an expert about your problem please reach out to us.