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When To Fix Pipe Belly? How To Fix It?

Pipe belly will become a serious headache for house owners when it clogs the pipe. Over time, the belly will cause standing water and sediment collection inside the belly.

So, when to fix pipe belly? As soon as you detect the issue, take steps to fix this issue. Upon noticing the symptoms, consult with an expert plumber for the video inspection process. Don’t proceed with the repairing method without any proper confirmation of belly formation.

In this article, we will discuss the causes, diagnosis process, and fixing method of the bellied pipe. You will also know about the cost of the fixing process. Thus, go through the article.

When To Fix Pipe Belly?

In the sewer pipe, there is a positive slope where it will decline 0.25 inches/foot minimum in each horizontal distance. This positive slope helps the movement of wastewater under gravity through the pipe. But sometimes, the pipe may sag slightly and correct itself again.

when to fix pipe belly

As a result, the waste can’t move forward under gravity and gets stuck there. If it remains like this untreated, here are some consequences:

  • The water flow or volume will slow down or even get blocked by the formation of blockage
  • Belly formation near joints can cause water leaks
  • Severe belly issues can cause serious property damage or collapse of the pipe
  • If this issue occurs in the sewer pipe, methane gas will leak from the pipe, which will cause gas poisoning
  • Also, sewer line bellies may cause backing up of the wastewater into the house, which may cause salmonella or E.coli caused diseases

Therefore, you shouldn’t neglect the pipe sag issue, even if it’s minor. Some people let it linger, thinking it’s a minor sag, but eventually, the sagging causes serious blockage. As a result, they end up spending a huge amount of money on repairing this issue.

Thus, we suggest you should consult with any professional plumber immediately after you detect any symptoms of the pipe belly. The sooner you will take steps, the less you need to spend on fixing it.

What Are The Causes Of Pipe Belly?

Belly formation of pipe can occur due to many reasons, such as:

  • Mistakes while installation of the pipe like improper grading materials, support, and impaction, can cause the settling down of the pipe in the ground
  • Extreme hot weather or temperature fluctuations can cause contraction or expansion of the pipe
  • Sometimes, leakages from the pipe fittings or rain can shift the soil around the pipe; eventually, it will disbalance the pipe support
  • Earthquakes may shift the pipe and cause the pipe to sag
  • Often, tree roots can provide excessive pressure on the pipe and can also move soil around the pipe
  • When the soil is of poor quality, it fails to provide strong structural support to the pipe. As a result, the pipe will move a lot under the ground and eventually may form a belly

How To Diagnose Pipe Belly Issues?

The earlier you can detect this issue, the more easily and cheaply you can solve that belly issue. Here are some ways to detect this issue:

  • Water flowing through your drains will get slow due to the blockage in the belly
  • Encountering clogged drain is also one of the common symptoms
  • You may also hear some unusual noises that will be coming from the pipes
  • Due to leaks in any fittings, you may notice wet ground or seeping water through the soil incidents near the pipes. Eventually, this will lead to pipe sag
  • To make sure that there is a belly in the pipe, you need to consult an expert plumber. They will conduct a video camera inspection on your pipe

They will attach a special camera with a cable and will insert that through the pipe. Thus, if there is any bend, sag, or settling of the pipe, they can see that through the video.

Check this Youtube video to visualize this method:

How To Fix Pipe Belly?

If you let the pipe sagging issue linger, it may cause more severe drainage issues shortly. To avoid this type of critical situation, you can take steps like:

Step 1: Excavation

When soil settling or grading is the reason behind the belly formation, there is no way except for excavating. An expert plumber will have the proper equipment for locating and digging the ground near the belly location.

Next, they will fill the ground beneath the pipe properly. Also, they can perform reinforcing of the pipe joints and compacting the soil for better results.

If the belly issue isn’t critical, with proper support from the ground, the pipe will come into its original position.

Step 2: Replacing

Sometimes, when the belly issues become too severe, the only way that will be left is to replace the pipe. The plumber will dig up the pipe and will replace it with a new pipe.

Generally, this method will be expensive and also time-consuming.

Step 3: Pipe Bursting

It is the trenchless method where the plumber will insert a bursting tool inside the pipe. The bursting tools will have a pneumatic or hydraulic expansion head which will expand the pipe along its length.

This method will resize the pipe and will remove the blockage.

Step 4: Cured-In-Place Pipe Lining (CIPP)

In this method, the professional plumber will pour a chemical inside the pipe. They will let the chemical get harden inside the pipe and will create a new lining inside the old pipe.

But the chemical that plumbers use in this method can cause many potential health risks. That’s because this CIPP method can cause air pollution and poison the wastewater of the pipe or groundwater near the area.

How Much Does It Cost To Fix Pipe Belly?

The cost of fixing the bellied pipe will depend on how critical the situation is and which method you are applying. Here, we will give you an idea about the cost of different methods, like:

  • For excavations, you may need to spend $2.50-$15.0 for every cubic yard
  • Replacing the pipe will be the most costly of all the methods. Generally, the cost will depend on the pipe size that you are replacing. For each foot of the new pipe, you need to spend around $50-$250

At a minimum, you may need to replace more than 10 feet of pipe. Besides, you also need to pay the cost of digging

  • In the CIPP method, for each foot of pipe,  the cost is around $80-$250
  • The bursting method will require $60-$200 for each foot of the pipe


In this FAQs section, we will answer a few most asked questions about the pipe belly.

Q: Is Pipe Belly And Channelling The Same?

No. The sewer line belly refers just to the sagging down of the pipe. But when the pipe bottom corroded away, people termed it as pipe channeling. Thus, the channeling issue is more serious than the belly issue.

Q: How Often Should I Get a Sewer Line Inspection Of My Home?

Typically, a professional sewer line inspection at least once a year is beneficial. If it’s not possible, at least have the expert inspection at least every 2-3 years.

Q: Can I Prevent Pipe Belly?

Yes. You can prevent the bellied pipe issue by following the proper installation and maintenance process. Also, upon noticing the ground settling, you need to take steps to address this.


There is no particular repair process for the saggy pipe, as the condition may vary with various factors. The less expensive trenchless methods won’t be possible if the sagging condition is too severe. In that case, excavating or pipe replacement is a must.

You can avoid the severity if you know when to fix pipe belly. Most importantly, you shouldn’t leave the issue untreated, thinking it’s a minor sag. Because, with time, this minor sag can cause major sediment acculturation and will clog the pipe partially or completely.