I get commissions for purchases made through links in this post.
How To Know if You Have a Main Sewer Line Clog

How To Know if You Have a Main Sewer Line Clog

How do you know if you have a Main Sewer Line Clog is something every homeowner should know.  Being able to quickly figure out if you have a sewer line break or clog could save you thousands of dollars and keep your home from becoming damaged. 

Here are the top 11 Ways to Know if You Have a Sewer Line Problem. 

What Happens if a Sewer Line Breaks?   

First let’s talk about why it’s so important to make sure that you keep your sewer pipes in tip top shape and inspect them regularly with the best sewer camera.  Every homeowner needs to be vigilant with their sewer pipes, because most of the time, a broken sewer line is not covered by insurance. 

How to Know if You Have a Main Sewer Line Clog?  

If you are a homeowner, it’s important to pay attention to signs that you might have a broken or clogged sewer line.  So, what exactly are the Signs of a Broken Sewer Pipe? Let’s review the ways to tell if the break or main sewer line clog is in your yard OR in your house. 

How do you determine if there’s a leak in the sewer pipe in your yard?

6 Signs You Have a Main Sewer Line Clog

Soggy Spots in Your Yard

Sewer Gas Odor

Extra Green Patches on Your Lawn

Lawn Has Indents

Large Trees with Big Roots

Driveway Is Sinking

There are a few ways to figure out if and where the sewer pipe problem is in your yard.  They are the first steps in sewer line leak detection.  Outside your home, check for these 6 things, which are telltale signs that you’ve got a sewer line issue.   

What are the 10 Signs of a Main Sewer Line Clog?

Soggy Spots in Your Grass or Yard 

Is there a few spots in your yard that never seem to dry out?  Are they soggy and wet year-round, even when its mid-summer? You might have a crack or leak in your pipe right underneath that soggy spot. 

Sewer Gas Odor in and/or Around Your House 

First things first here.  Make sure to check in the P trap inside your drains.  The P trap is built to hold water in it to prevent any sewer line gases from getting back up into your home.  It could be plugged or have some other issue with it, that’s letting the gas vent back into your home.   

If the P trap is fine, then start looking around for the source of the odor.  Backed up sewage and grey water isn’t going to smell like roses, it will stink.  Once you find the approximate location of the source of the smell, you’ve probably located your leak. 

Extra Green Patches on Your Lawn 

Even if your lawn isn’t soggy, there might still be a leaking pipe underground.  Another telltale sign is when your lawn has patches on it that are super green compared to the rest of your lawn.  The sewer drains underneath might be leaking and the nutrients from the water are feeding your lawn, making it that lush green in random spots. 

Lawn Has Indents 

Similar to a sinkhole, your lawn will sink down a bit if there is a leak underneath it. 

Large Trees with Big Root Systems Could Mean Roots in Your Pipes 

Be careful when planting trees on your property.  Only plant tree species that are NOT going to develop huge root systems that can mess with your pipes, driveway, foundation, etc.  If the tree was there when you bought the house, you will have to address it or you’ll be constantly fighting with the roots to stop them from damaging your property. 

Your driveway or Other Paves and Bricked area are Sinking 

This is because the water leak underneath is causing a sinkhole, and you are seeing “potholes” in your driveway as the water and soil compress underneath.  That sinkhole is a sign of the location of your leak. 

4 Ways to Tell if You Have a Leaking Sewer Pipe or Drain in Your Basement or House 

There are a few ways to tell on the inside of your house if you have a drainage issue.   

Main Sewer Line Clog and Mold in Your House 

No one wants mold in their home, its so unhealthy. If you’ve never had a mold problem and suddenly, you start finding mold in your bathroom, basement, closets, or even the corners of your rooms, you might have leaking drain pipes.

Those leaking pipes are building up humidity under your home. The moisture is then getting into your home and causing mold to grow.

Slow Drains 

This one is pretty easy to see. If your drains and toilet start draining slower and slower, then you could have a main sewer line clog. There are many reasons why your drains would be clogged. Maybe something was flushed, there is a build up of grease and gunk, or there could be roots in your pipes.

Get a sewer line inspection sooner instead of later to keep a small problem from turning into a huge emergency.

Cracks in your foundation, sinkholes or “settling” of foundation 

Long term leaks cause sinkholes and depressions in the soil under your home. This can cause your house to “settle” unevenly resulting in the walls cracking under the pressure of their own weight.

Also, if you notice your doors never fit quite right and are shifting slowly over time, your house might be “settling” and shifting. Get those drain pipes checked as part of your problem solving.

Main Sewer Line Clog & Rats, Mice and other Pests 

Rodents can squeeze themselves through small cracks in your pipes and make their way into your home through the toilet and drains. If you start noticing a rodent problem and you’ve tried everything to stop it, check your drains.

Same goes for insects. They can get into cracks in your pipes and make their way into your home. DISGUSTING!


Determining if you have a main sewer line clog, a break or any other problems as fast as possible could mean the difference between a small problem and a huge disaster that most likely won’t be covered by your home insurance.  Using our tips above, you should be able to figure out that you have an issue and get it dealt with immediately.