8 Important Signs of a Collapsed Sewer Line (& What To Do About Them)

Becoming a homeowner is typically a well-earned accomplishment, however it comes with great responsibility. One of those responsibilities is ensuring that everything in the house functions properly. Thus, a collapsed sewer line, or damage that prevents distribution of waste to a civic sewer system, can quickly become a nightmare.

The signs of a collapsed sewer line are strong sewer odor, drains that take longer to clear, sewage backup in your tub or toilet, mold or mildew, cracking walls, pest infestations, and a soggy or greener lawn. When you notice a problem, you should seek a rooter and cleaning service, hydrojetting, pipe lining, video camera inspection, pipe bursting, or replacement. 

This article will walk you through the signs that you should be aware of when assessing whether your home has a collapsed sewer line. By performing an initial assessment you will be able to better decide the correct next steps to fix your sewer line as quickly as possible.

What Are The Signs Of A Collapsed Sewer Line?

The signs of a collapsed sewer line are strong sewer odor, drains that take longer to clear, sewage backup in your tub or toilet, mold or mildew, cracking walls, and pest infestations. 

Sewer odor and sewage backup are two of the most obvious signs your sewer line has collapsed. Issues in other areas of your home, such as walls and sink drains, may also be affected. A collapsed sewer line may also bring mold, mildew, and pest infestations into your home. 

The status of your lawn can be another indication of a problem with your sewer line. If you notice the grass is wet or soggy, this may be a sign of a collapsed line. 

Similarly, greener patches of grass in certain areas are a tell-tale sign of sewer line problems. This is due to the fact that human waste provides nutrients to the soil, promoting faster growth. 

1. Strong Sewer Odor 

A strong smell in and around your home can mean a broken pipe or a sewer clog. Sanitary sewers should be airtight other than the vent cracks used to move sewage, so the smell of sewer gas is a good indication that something is amiss.

Sewer Blockages Odor 

The smell could be coming from your front yard or inside your house – the basement is the most common area for odor. If you can smell sewer gas, it is important that you call a certified technician to investigate and fix any issues with your sewer line to prevent any further damage to your home. 

2. Drains That Take Longer To Clear 

If all of the drains in your home are taking longer to clear, this could be a sign of a collapsed sewer line. When multiple drains in your home are slow to clear, you should consult a professional about potential issues with your main sewer line, since all drains use it for drainage.

Pumping the Drain

A single drain that takes longer than usual to drain may not be a direct indicator of a collapsed sewer line, however, it does indicate that there may be a blockage, and this could eventually lead to a collapsed sewer if not treated as soon as possible.

3. Regular Sewage Backup In Tub Or Toilet 

Frequent backups in your tub or toilet can mean a collapsed or clogged sewer line. Lower areas of your home, or areas closest to the main sewer line, are likely to begin experiencing backups first, since water from other areas moves there in order to connect to the main sewage line. 

Yellowish Water on Drain

When that passageway is clogged, the water will return back to your toilet or tub since it cannot pass through the main line. If the backup is limited to one drain, you can focus on alleviating the blockage, but keep an eye out on other areas starting to backup as well.

4. Mold Or Mildew Growing On Your Ceilings Or Walls 

Visible mold or mildew growth in your home could be a sign of a collapsed sewer line since it is an indication that there is a lot of moisture. With the presence of water and humidity, mold and mildew have the opportunity to present themselves. 

Mold on Ceilings

While there can be a variety of causes for mold and mildew in any area of the home, spores growing on the ceilings or walls are likely to stem from the sewer line. This is due to the location of the line being behind the walls. If you notice any fungal growth in these isolated areas, there’s a good chance your sewer line has collapsed. 

5. Walls Beginning To Crack 

Cracks in your wall are another sign of a collapsed sewer line and should be addressed as quickly as possible to prevent structural or foundation damage. It is recommended that you call a foundation specialist immediately as you begin to notice cracks in your wall so that they can assess the level of damage that is present. 

Cracks on Wall

A collapsed sewer line can cause soil beneath your home to shift or wash away, which will cause the foundation of your home to weaken. In a worst case scenario, if an issue like this is untreated the foundation can give way to the weight from above causing your home to collapse.

6. Invasion Of Pests In Your Home 

If a sewer line is broken, it could create an opening for pests to get into your home. If you see an increase in cockroaches, palmetto bugs, sewer flies, or even rodents, you may be experiencing a pest infestation due to a collapsed sewer line. 

Pests on floor

Rodents and insects can cause a number of health issues, especially in children. If there is an entryway via sewer line into your home, the pests will never stop coming. It is in the best interest of your home and your family safety to locate and fix the broken sewer line.

7. Patches Of Grass That Is Greener On Your Lawn

An increase in fecal matter due to a collapsed sewer line could cause patches of greener grass in your lawn. Fecal matter contains nutrients as it is a natural fertilizer, which can lead your grass to grow faster and become more lush. This may start small at first, but over time you will see a dramatic difference in the areas near the collapsed line. 

Patches on Grass

While this may seem like a bonus to a bad situation, eventually those areas will become oversaturated and the grass will die from too much water, or bacteria and contaminants from sewer water. 

8. Soggy Lawn 

As mentioned above, a collapsed line can cause odors around your home. Additionally, if you see that your lawn is becoming soggy, this is a good sign that there is a collapsed sewer line. Unfortunately, untreated, this can lead to a sinkhole in your yard, so it is a condition that should not go untreated for long. 

The smell and swampy conditions of a lawn can attract rodents and pests, which could eventually make their way into your home, or overall increase the hazardous conditions within your home.

What Should I Do About A Collapsed Sewer Line 

The common signs of a collapsed sewer line include clogged drains, overflows, mold on the walls, and an infestation of pests and rodents. You may also notice changes in the moisture or growth of your front lawn. 

When you notice the signs of a collapsed sewer line, you should call a professional as soon as possible. They will be able to assess the damage and come up with the best course of action to take.

Different sewer line problems will require various solutions. Below, we will get into the services that most professionals offer for collapsed sewer lines. 

Rooter And Cleaning Service 

Rooter and cleaning service utilizes an electric sewer cleaning machine to cut through sewer clogs. These may be caused by tree roots or other debris. The machine then cleans the entire length of an underground sewer pipe to get water flowing freely again.

The rooter blades are spring loaded to help them fit into the pipe. When the machine turns on, the blades spin and shave the pipe walls of all debris and roots that have penetrated the sewer pipe at the pipe joints or through cracks.


Hydrojetting uses water to push waste and build up further down the pipes. This method is ideal when chemical solutions have not worked in the past. The pressurized water can break up anything from food and grease to toilet paper masses. 

This is one of the most long-term solutions for a collapsed sewer line. By cleaning the inside of the pipe, it clears the area of any buildup and debris for smoother operation moving forward. 

Pipe Lining 

Pipe lining is the process of “lining” one pipe with another. When a sewer line collapses, professionals can place a smaller pipe on the inside to repair it. 

This method is highly effective and minimally invasive. Pipe lining repairs the problem of a sewer line collapse without the interruptions and complications of a full replacement. 

Video Camera Inspection 

Video camera inspection is a technique used by professionals to properly assess damage in hard to reach places. A small camera travels through the sewer pipe on the end of a flexible cable to accurately identify the problem. 

Without these specialized tools and techniques, professionals would not be able to see past the twists and turns of your sewer pipe. It’s the most ideal way to identify the exact problem instead of guessing based on other factors. 

Pipe Bursting 

Pipe bursting is another trenchless sewer repair technique. Similar to pipe lining, it doesn’t require any digging into the ground to complete. 

The process involves inserting a new pipe in place of the old one. No removal is necessary beforehand, as a cone-shaped head on the new pipe breaks apart the old one in a single motion. 

Sewer Line Replacement 

Sewer line replacement is necessary when repairs are not possible and problems become a hazard to your household. A sewer line that is collapsed can cause sewage backup in several places around the home. In addition to unpleasant odors, sewage backup can contribute to mold, mildew, rodents, and structural problems. 

While repairs such as pipe lining or pipe bursting may be possible, more severe cases will require full replacement. The average cost for sewer line replacement is $5,000. 

Depending on the area you live and professional you choose, this cost can be as low as $3,000 all the way up to $6,000. The typical cost of sewer line replacement depends on the pipe length, averaging between $50 and $200 per linear foot. It’s best to consult with a local professional to determine exactly what you can expect to pay for your upcoming sewer line replacement. 


A collapsed sewer line can be a concerning problem for any homeowner to deal with. When you notice the signs of sewer line problems, it’s important to get ahead of it by calling in a professional as soon as possible. They will know how to assess the problem and identify the best solution for your household. 

The key indicators of a collapsed sewer line to look out for include soggy grass on your lawn, mold and mildew on the walls, rodents and insects, and regular sewage backup in your toilets. A strong smell of sewage can also point to a collapsed line. 

Common solutions to a collapsed sewer line are hydrojetting, pipe lining, pipe bursting, and rooter and cleaning service. You may also need a video camera inspection to assess the damage, and replacement will be necessary if the damage is too great or none of these steps work. 

The most valuable tip to keep in mind is not to ignore the signs of a collapsed sewer line. When you keep an eye out for these indicators, you can stay on top of regular maintenance and repairs to avoid expensive replacements in the future. 

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