The biggest cause of blocked sewer pipes


I had a proud moment tonight as I watched Channel 9 news. The plumber that I have been referring work to since dad and I stopped working was featured in a report about the biggest cause of pipe blockages in QLD (and Australia). Graeme was always on my speed dial whenever one of my clients would need a drain unblocked. He had the right machine and owned a drain camera that could locate what was causing the blockages. He’s one of the plumbers that would help me out when I’d be away or needed an extra plumber to help with our maintenance business.

Anyway, if you didn’t catch the news report last night, the biggest cause of blocked sewer pipes in QLD is tree roots. I’ve typed about what causes toilet and pipe blockages and what you should flush down your toilet. Interestingly a landscaper was interviewed about what trees to avoid planting on your property and which ones you can plant instead because of their non-invasive root systems.

The trees to avoid planting in your garden or anywhere near your sewer line are Paperbarks, Bottlebrushes and Fig Trees.

Trees to plant instead are Gardenias and Lemon Myrtles. Another was also mentioned but I didn’t get to write it down.

Before you plant a new tree or plan your landscaping, check where your main sewer runs and check what type of root system your trees will have. If they have an invasive and strong root system, they have the potential to grow through your sewer pipe.

I’ve heard mixed causes of how tree roots penetrate pipes. I’ve heard that the pipe needs to be already broken (due to movement in the ground) which allows roots to grow through the pipe. But other experienced plumbers have advised that the tree roots can strangle a pipe and cause it to fracture allowing the roots to find their way through the pipe.

No matter how the pipe gets broken, it’s best to avoid running a house sewer line near large trees if you’re building in a new area where there are a lot of Paperbarks. If your house is well established and you have a council tree that causes problems, it’s best to discuss the matter with the council about what you’re options are on removing it. Most times, the trees are protected which angers me because while the roots can cause expense to plumbing, the trees have the potential to cause damage to a home in a storm if they fall. People’s lives are more important than trees!

If you have issues with tree roots here are your options in trying to eradicate the problem:

  1. Call a plumber every 18months to 2 years to continually cut the roots inside the pipe. This is costly in the long run, and an inconvenience, but a cheaper short term option.
  2. Excavate and dig up the main sewer and replace the broken section. This can be expensive. You’re looking at a bill in the thousands range. The main cost is caused by the excavation, shoring and labour needed to reach the sewer if it’s more than 1.5 meters deep. I know of one client where their sewer is broken but it’s 3 meters deep. The cost of replacing the pipe will be thousands of dollars so they opt for option 1.
  3. Reline the inside of the sewer pipe with a sleeve. This avoids digging up the sewer. This option is not always successful and I’m not sure on the pricing but I do know that it can be pricey as we did it once to a sewer line in the city that couldn’t be excavated. The good thing about this option though if it is successful, it has a good guarantee on installation. Check with the installer for more details on pricing and installation guarantee.

Have you experienced a pipe blockage due to tree roots? How do you maintain it or did you get it replaced? Do you live in an area with a lot of trees?

The main image was sourced from Balkan Plumbing.