Roots in a sewer line

One of the most common issues I see in a sewer scope inspection is roots in the pipe. I am writing this to answer some of the most common questions I get.

What is a sewer pipe?

Why do roots grow into a sewer pipe?

Why do I care if there are roots in my pipe?

Do roots mean I need a whole new pipe?

Does hydro jetting fix the pipe?

How do plumbers go about fixing it?

Let's start by defining a sewer pipe. In this article, I am referring to the pipe that connects your house to the city's sewage pipe. I will not be addressing septic systems. All the drains in your house, including sinks, showers, toilets, etc. connect to a pipe that goes from under your house, usually through the front, under the garden, under the sidewalk, and to the city's pipes that typically run under the street. The homeowner is responsible for that whole pipe, even though portions of the pipe are not under your property.

Why do roots grow into sewer pipes?

Roots act as the foundation of a tree and also allow the tree to drink. Most trees are larger underground than they are above ground, meaning if you have a large 30-foot tree 40 feet away from the sewer pipe roots can still grow in. Another thing to keep in mind is that roots can live for several years after cutting down a tree, so even if there are no trees near the pipe, they can still grow in. Trees need water, nutrients, and sunlight in order to grow. Your sewer pipe has water, and it might sound gross, but feces is a good source of nutrients for your tree (That is why many people will put cow manure on their lawn to help it grow). As we see from here a sewer pipe is a tree's dream.

Why do I care if there are roots in my pipe?

Once the roots get into your pipe, they will keep growing to get all the water they can. Eventually the roots will block the pipe and cause a sewer backup. Signs of a sewer backup include sinks not draining, sewage coming up out of your shower and bathtub drains, and if you are lucky a sewer cleanout cap in front of your house opening and dumping all your sewage in your garden. (remember even if the seller never had any issues, it is possible you will use more water at once than they did. In addition, the roots will keep growing and eventually lead to backups.) Another thing to keep in mind is that if roots can grow in, sewage can leak out of your pipes leading to environmental issues.

How do most roots get in?

Clay pipes typically come in 20-foot sections, and are joined together on site. They are very strong and rarely break. They used to use mortar and tar to join the pipes together, however, this causes the whole pipe to become solid not allowing it to settle over time. When the ground settles, over the season, or shakes in earthquakes, it breaks the joint. Roots will take advantage of this and get in. Thankfully newer clay pipes use a flexible urethane joint allowing the pipe to settle without damaging the joint.

Does hydro jetting fix the pipe?

Once roots grow in, it means the joint is damaged. If the pipe is fully blocked by roots it can cause the sewer pipe to back up into your house. Hydro-jetting is a fast and relatively cheap way to temporarily unclog the pipe. It works by blasting extremely high-pressure water into the pipes, breaking up the roots. This will allow sewage to flow through the pipes and stop the backup, however, it does not fix the pipe. Roots will grow back and sewage can still leak out from the broken joint leading to environmental issues.

How do plumbers go about fixing it?

There are a few options to fix a damaged pipe. The most invasive, but still sometimes the best way is to dig up the pipe and replace the damaged joints, or even the whole pipe. This can get costly due to the excavation work needed. (This should only be done by a qualified professional due to the risk of hitting an underground utility, such as gas or power, always call 811 before digging)

Some things can cause the price of this to go up. A large portion of the sewer pipe is under the city's property, and the city does not allow anyone to just start ripping up the street and sidewalk. A plumber must have a C42 license and is usually required to get a bond in order to damage the city's property. This is to insure if the job was not completed to the city's standard it can repair it using the bond. While very rare the pipe may also go under your neighbor's property line, in which case you would need their permission to dig up their property. It may also go under a driveway, walking path, sports court, etc. which will add even more cost to fix the surface.

Sometimes a more viable option can be a liner. The liner is placed in the pipe when it is flat and wet. A bladder is filled inside the liner to allow it to form to the shape of the old pipe while it hardens and dries. An average liner is rated to last around 50 years and is a great choice when feasible. However, there are some limitations to this as well. Because the liner is taking on the shape of the old pipe, the shape of the old pipe must be within a certain margin, and if the pipe has large offsets between the sections, it's not a great candidate.

Sometimes, although very rarely, the best plan of action is to dig a whole new sewer line. This can get very costly due to having all the excavation costs and having to join in with the city's pipes.

Thankfully there are new technologies that are coming out every day. An up-to-date plumber with all the newest tools and techniques will be able to come up with the best repair for your scenario.

In conclusion, roots usually grow into clay pipe from the joints. While hydro jetting can open a clogged pipe, it is not a permanent fix being that they will grow back and contaminated water can leak out. There are several techniques to fixing roots in your pipe, which vary in price significantly. It will get far more complex to repair when it is under someone else's property (such as the city). You should always get a good plumber who is up to date with the newest techniques and can find the best way of resolving your issue.