Drain Excavation – Why, Where, When?

 In Drains & Sewers

Drain problems can run from the relatively minor issue that can be addressed by the homeowner to serious repairs that require the immediate attention of a professional plumber. When you start to notice problems with the drains in your home and find that nothing seems to solve the issue, it is time to call in a professional for a full inspection of the drain line.

If you are having significant problems with your drain, it might mean that it is time to get the sewer line replaced or repaired. In most situations, a plumber might be able to handle the issue with one of a few different trenchless drain repair methods. However, there are still some situations where the repair or replacement may require drain excavation.

Excavation tends to be much more labour-intensive and it is going to be much more disruptive to the property. For this reason, most plumbers and homeowners prefer trenchless methods for repairing and replacing drains. In this post, we are going to look at drain excavation and the options that you have when drain repairs are necessary.

When does a drain need to be repaired or replaced?

This question has no straightforward answer. The lifespan of a sewer line is going to depend on several factors. The material from which the pipe was made is one important factor. You also have to consider soil conditions and other conditions to which the drain was exposed. There are also different events and ecological factors that can damage or compromise a drain line. The following are a few factors that could contribute to the need for drain replacement and repair.


A sewer line could be made from a wide range of different materials. You have metal pipes, clay, plastic, concrete and a whole host of other materials. As the line ages, corrosion can wear away at the materials or the joints could start to go.

Soil Conditions

The soil conditions around the line can cause problems. Depending on the conditions, the line could crack or collapse, freezing soil can damage lines and you may find issues where the soil shifts and causes part of the sewer line to go out of pitch.


Sewer lines can also get blocked by obstructions. In most cases, a plumber should be able to remove an obstruction from the line, but there are some that will not move without accessing the pipe. It could be waste materials from the toilets or it could be a build up of food and grease from the sinks.

Tree Roots

If you have a large tree on your property, the roots could invade the line and cause problems. When roots grow into the line, they not only damage the drain, but it can also cause a blockage that will be difficult to remove.

Any number of issues could result in the need for replacement or repairs. In many cases, it isn’t just one problem. Instead, you have a variety of factors that come together to damage the drain line. If you suspect that your drain might need repairs or replacement, you need to call a plumber. The plumber can inspect the line using a drain inspection camera, and they will be able to recommend and perform the necessary repairs.


How do I know if my drain needs repairs?

If you have a compromised sewer line, it is important to get it fixed right away. A damaged drain can contribute to other problems in the home, and it can also lead to living conditions that are unsanitary. For this reason, you should know the signs that can indicate a need for drain repair.


One of the most obvious signs is a problem with blockages to the line. This is especially true if the blockages occur to more than one drain. If you have noticed that you have blockages to multiple drains, it is a sign that your sewer line has a problem. If you get the lines cleared only to find that they repeatedly have problems, this is another sign that there is an issue.

Slow Drains

In some cases, the drains are not completely blocked, but you may notice that your sinks or toilets seem to drain slowly, or that you have to flush more than once for the toilet to empty. This is another sign of a problem. In this case, the line might not be completely blocked off, but there is some type of obstruction that is limiting the flow on the drain line.

Sewer Gas

The smell of sewer gas around sinks and toilets can indicate that there is a problem with the line. You may also notice the smell of sewer gas around the property. This could be a sign that the line is broken or cracked. If you start to smell sewer gas around the home, it is time to call a plumber.

Indentations and Sinkholes

When a sewer line leaks, it can affect the soil in the surrounding area. In some cases, this might cause the soil to dissipate and this could lead to an indentation in the lawn near where the sewer line is. In some extreme cases, it may even result in a sinkhole on the property.

Patches of Healthy Grass

The waste that leaks from your sewer line can act as a fertilizer and make for an area of the lawn that is particularly lush. You may think that area of the lawn looks great, but it might be a sign that your sewer line is leaking.


What about trenchless drain repair?

Excavation used to be the only option if you needed to repair or replace your drain lateral. Since the development of trenchless drain repair methods, they have become the favoured option for most plumbers and drain repair specialists.

With excavation, you have some problems that don’t come with trenchless drain repair. To start, the excavation process takes more time and effort, and this increases the cost of the repair. As an additional issue, it can be very disruptive to the property. The excavation process can damage landscaping and you may even need to dig under things like patios and walkways.

With trenchless drain repair, there might be the need for some minor excavation, but it is not nearly as extensive as having to dig up the entire line. This cuts the time and the cost down significantly and it also saves on all of the damage that could be done to landscaping and hardscaping that might be on the property.

When you talk about trenchless drain repair, you have two basic options: cured-in-place pipe lining (CIPP) and pipe bursting. Both of these methods can be used to provide effective, durable repairs for damaged drain lines, but they both have their own ideal applications.

With CIPP, a liner is applied to the damaged pipe. This liner is held in place using air pressure and an epoxy resin is used to fix the liner to the pipe and seal off the damage. This can be good for sealing cracks and punctures to pipes that are underground, and it provides a very reliable solution that is also cost effective.

Pipe bursting is a method for replacing underground pipes without having to dig the entire line up. With pipe bursting, the new pipe is run down the existing line. The new pipe is fitted with a bursting head that is used to crack and displace the old line. As it is pulled through the line, the old pipe breaks and the new pipe takes its place.

These two methods alone can be used to address a wide range of issues where an underground pipe needs to be repaired or replace. That being said, there are still some situations where excavation is the only option.


When is excavation needed?

At this point, you might be wondering why people don’t just use trenchless drain repairs for every repair or replacement project. It costs less, it is less disruptive, it is less invasive and it can be done in less time. In any situation where it is a viable option, a plumber is likely to go with a trenchless option, but there are some factors that can take these options off the table.

One point is that CIPP is only good for repairs. If the pipe needs to be replaced, CIPP is an option that is not going to get the job done. Some repairs may also be beyond the capabilities of a liner. If a joint in the line is broken, you might need to excavate. If the repair is long and far from the access to the line, a liner might not be able to cover the problem.

Pipe bursting also comes with its own issues. When the pipe and bursting head are being pulled down the line, it causes vibration in the soil. Depending on the soil conditions, this could be a problem. If the line runs too close to other utilities, pipe bursting might cause a problem for other lines that are run nearby. You also have to consider the material. Pipe bursting will not work with certain materials. Depending on where you live, you may also have to consider issues with permits. Some municipalities require special permits for pipe bursting, and there are even some that do not allow it at all.

If one of the trenchless repair methods is an option, there are definite advantages to using them. Your drain will get fixed in less time, you’ll spend less on the repair and you won’t have to worry about your yard getting dug up. However, you might have to accept excavation as the only option that is available. When it comes time to replace a drain line, your plumber should lay out all of your options and explain the positives and negatives of each option.


Which option is better?

It’s not really a question of which of these repair options is best; the best repair is determined by the situation. In some cases, cured-in-place pipe lining will be the best repair for the situation, in others, you may have to go with pipe bursting or excavation. An experienced plumber will be able to inspect the drain line, evaluate all of the factors and come to a recommendation for the best repair for the situation at hand.

With CIPP, you are looking at repairs for cracks and punctures to the line. In most of these situations, CIPP is the best repair. It provides a reliable repair that can last many years, it is relatively quick and it will not require a lot of digging. Most of the liners even come with an extensive warranty, so if there is a problem, you are covered.

Pipe bursting is the ideal solution for many situations where a pipe needs to be replaced or upsized. The new pipe can easily follow the line of the old pipe, and it makes for a reliable repair that will last many years. You can even replace runs that are very long with pipe bursting, but as I mentioned before, there are some situations where it is not an option.

Plumbers will generally only recommend excavation as a last resort. It means that the repair cannot be fixed by lining, and that either the soil conditions, material of the pipe or the presence of other utilities have ruled out the possibility of pipe bursting. If the pipe is improperly pitched, that might be another reason to go with a full excavation.

All of these options can provide good, reliable repairs. None of them is any better than the others. CIPP and pipe bursting might have some advantages that make them preferable, but it all comes down to the situation.

Sewer line problems can take on many different forms, and for that reason, there are different types of repairs that can be applied. If you are fortunate, you will be able to take advantage of one of the trenchless drain repair methods, but in some situations, they might be an option. If that is the case, a full excavation can still provide you with the repairs you need.

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Showing 4 comments
  • Steven Warren

    What I learned from my personal experience is; while choosing a plumbing company for excavation or repairing of a drain pipes, one should have details about the exact location of underground pipes. A few months ago, I hired a plumbing company to fix leaked drain pipe and they created further chaos by damaging other pipes too. Thank you for the tips!

  • Vera Graham 

    Sewer line of my home was constructed mainly with concrete and we had a lot of trouble to perform drain excavation on it and for doing up-size on the same. Since then, I never recommend anyone to use concrete as material.

  • Katherine Wong

    I suggest everyone to act timely and don’t wait to be flooded with ground water. Make sure you have drilled a pump line to suck out the water from the ground to property perform the excavation. And, while doing so, always take safety precautionary measures by hiring professional excavators.

  • Randy H. Williams

    I faced it at my home and strongly believe that drain excavation is extremely complex task and involves careful safety monitoring and if not done correctly, may result into more cost. One more thing, it should be utilized as a last resort and only when drainage issue is so troublesome that other applicable methods have already failed.

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french drain in a ditch before being installed