Tree roots get into sewer pipes through tiny cracks and loose joints, usually in older clay or earthenware pipes. Roots are drawn to the moisture and nutrients leaking from the pipe, so they push in, branch out, and grow into a thick mat that catches waste. Left alone, they widen the opening and can lead to a collapsed pipe.
Roots grow toward water and nutrients. A sewer pipe carries both, and even a tiny leak releases moisture and vapour into the surrounding soil. In dry spells, that damp patch is the most attractive spot in the garden. Sydney's clay soils, which shrink and swell with the weather, can also move pipes and open joints, which makes the situation worse.
Modern PVC with sealed joints is much more resistant, though a poorly fitted joint can still be a way in.
Fine, hair-like roots find a gap and push through. At this point you'd notice nothing at all.
Inside, the roots find a steady supply of water and nutrients, so they thrive. They branch into fibrous mats.
As roots thicken, they push the crack or joint further apart, which lets more roots in.
The root mat catches toilet paper, wipes, grease and other waste. Sydney Water says wet wipes are linked to 75% of its wastewater blockages, and roots give them something to snag on. Drains slow down, gurgle and eventually back up.
Weakened, cracked pipes can sag, shift or collapse. A collapsed pipe often needs excavation, which is far more costly and disruptive than an early repair.
Any tree can invade a leaking pipe, but some are notorious: Moreton Bay and other figs, willows, camphor laurels, liquidambars, jacarandas, plane trees and large eucalypts. Sydney Water advises keeping trees at least 6 metres from wastewater pipes, and publishes a list of trees to avoid planting near them. Check the current guidance on its website before planting.
One slow drain is often a simple clog. Several signs together, or a blockage that keeps returning, point to a problem in the main line. See our guide to the signs of a collapsed sewer line or try our drain problem checker.
According to Sydney Water, you're responsible for wastewater pipes from your property up to where they connect to its network, so a root blockage in your private pipes is generally your job to fix, using a licensed plumber. A blockage is more likely to be in your private pipes if your neighbours aren't affected, the drain isn't shared and overflows happen only when you use water on your property. If you're unsure, or sewage is overflowing from the street, call Sydney Water on 13 20 90. If a private pipe has collapsed under a public road or footpath, Sydney Water may repair it for free in limited cases, and only if a licensed plumber confirms digging is the only option.
A camera shows where the roots enter, how far they've spread and whether the pipe is still sound. This is the step that decides everything else. Learn more about our CCTV drain camera inspections.
High-pressure jetting or mechanical cutting removes the roots so the pipe can flow, and so a repair can go in. It clears the blockage, but the opening is still there. See our tree root removal from pipes service.
For cracked or root-damaged pipes that still hold their shape, pipe relining creates a smooth, sealed liner inside the old pipe, which shuts roots out. Relining can't fix a fully collapsed or badly sagging pipe, and a camera inspection will tell you which you have. For costs, read how much pipe relining costs in Sydney.
Can you prevent roots coming back? Yes, with a sealed pipe, smart planting and regular checks. Our guide on how to keep roots out of drain pipes covers it.
If your drains are slow, gurgling or backing up, find out whether roots are the cause before the pipe gets worse. Sydney Drain Surgeons are licensed drainage specialists serving Sydney and Wollongong. Request a free drain inspection quote. Same-day service is available.
Roots enter through small cracks and loose joints, drawn by moisture and nutrients leaking from the pipe. Once inside, they grow and branch, forming blockages and widening the opening.
Roots usually exploit an existing crack or joint rather than breaking a sound pipe. But as they thicken, they can push the opening wider and weaken the pipe until it fails.
The main signs are slow or gurgling drains in several fixtures, backups in your lowest drain, sewage smells, and lush or soggy patches in the yard. Blockages that keep returning are a strong clue.
Sydney Water advises keeping trees at least 6 metres from wastewater pipes. Species matter too, so check its list of trees to avoid.
It clears the blockage, but roots usually grow back through the same opening. Sealing the pipe, for example by relining it, stops them returning.
A properly installed liner seals cracks and joints, which removes the openings roots use. Ask your plumber about the liner system and warranty.
It is if sewage is backing up into the house. Stop using water and call a licensed plumber. A slow drain with no backup can usually wait a day or two for an inspection.
Generally the property owner, for pipes up to the connection with Sydney Water's network. Some insurance policies cover root damage and others don't, so check your PDS.
