Preventing blocked drains caused by tree roots in pipes

Most people don’t think about what’s happening underground until a drain stops working. By that point, tree roots have often been growing inside your pipes for months - sometimes years.

Melbourne’s older suburbs are full of established trees sitting right next to ageing clay and earthenware pipes. Those pipes crack and shift over time, and roots find the gaps. They’re drawn to the moisture and nutrients inside your sewer and stormwater lines. Once a fine root hair gets in, it keeps growing until you’ve got a full blockage.

Why roots get into pipes in the first place

Roots don’t attack pipes randomly. They follow moisture. A tiny crack, a loose joint, or a section of pipe that’s settled and separated - that’s all it takes. The root finds the leak, enters the pipe, and feeds on what’s flowing through it.

Clay pipes laid before the 1980s are the most vulnerable. PVC holds up better, but even modern pipes can be compromised at joints if they weren’t installed properly. If you’ve got large trees within a few metres of your drainage lines, there’s a fair chance roots are already making their way in.

The real problem is that roots don’t stop growing once they’re inside. They expand, trap debris, and eventually form a solid mass that blocks the pipe completely. Left long enough, they’ll crack the pipe open from the inside.

Signs that roots are in your pipes

A few things to watch for:

• Slow drains that keep getting worse over weeks or months. Not a sudden blockage - a gradual one.
• Gurgling sounds from toilets or floor wastes, especially after flushing or running a load of washing.
• Recurring blockages in the same drain. You clear it, it comes back a few weeks later. That pattern almost always points to roots.
• Patches of greener grass over where your sewer line runs. The roots have cracked the pipe and nutrients are leaking into the soil.
• Sewage smells around drains or in the yard, particularly after rain.

If you’re getting repeat blockages, a store-bought drain cleaner won’t sort it out. It might push water through temporarily, but the roots are still there and still growing.

What you can do to prevent root intrusion

If you’re building or renovating, think about where your trees are relative to your drainage. That’s the best time to get it right. For existing properties, here’s what actually works:

Get a CCTV inspection. A drain camera inspection shows exactly what’s happening inside your pipes. We can see root entry points, cracks, and how far the intrusion has spread. It takes the guesswork out of it.

Install root barriers. Physical barriers placed between trees and pipe runs stop roots from reaching your drainage. They’re worth considering if you’ve got large trees you don’t want to remove.

Choose your plantings carefully. Some species are worse than others. Willows, liquidambars, and fig trees have aggressive root systems. If you’re planting near drainage lines, go with smaller species that have less invasive roots.

Stay on top of maintenance. If you know you’ve got trees near your pipes, a camera check every couple of years catches problems early - before you end up with a full blockage or a cracked pipe.

How we clear roots from pipes

DIY methods don’t work on root intrusion. Chemical root killers might slow things down slightly, but they won’t remove the mass that’s already formed inside the pipe.

We use hydro jetting to blast roots out of pipes with high-pressure water. It’s fast and it clears the full bore of the pipe. For heavier infestations, mechanical cutting tools grind the roots away. You can read more about our tree root clearing process.

Once the roots are out, we run the camera through again to check the condition of the pipe. If there’s damage, we’ll talk you through the options - whether that’s pipe relining to seal things up without digging, or a section of pipe repair if the damage is more serious.

When to call a professional

If you’re dealing with one slow drain, it might just be a local blockage you can clear yourself. But if multiple drains are slow, you’re getting recurring blockages, or you can smell sewage - that’s not a DIY fix.

We deal with root-damaged pipes across Melbourne every week. Give us a call on 1300 303 247 to book an inspection and we’ll tell you exactly what’s going on before any work starts.