Plumbing camera footage of tree roots in a sewer pipe can look like something from a horror film. For one Perth strata committee member, it was real.

They posted on Reddit about a row of large gum trees on the street outside their apartment block. One tree’s roots had worked their way into the sewer pipe under the building’s bin room. The plumber’s suggested fix was to cut through the slab, replace the cracked pipe and re-concrete.

Their questions: are there alternatives, and how do you stop the roots getting back in?

Andy from Swell Building Inspections talked it through with host Jordan in our Pro Insights series.

Here’s the short answer: jetting clears the roots but won’t stop them coming back. For a lasting fix, the cracked section needs to be sealed or replaced. Pipe relining is usually the least invasive option, from around $3,000 for a short section. Cutting the slab and replacing the pipe also works, but it’s more disruptive and harder to price.

Why Tree Roots in a Sewer Pipe Are a Big Deal

For a strata property, the stakes are high. If that pipe is the main sewer line running to the street and it becomes completely blocked, every unit loses its plumbing. Nobody can flush a toilet, run a shower or use the sink.

At worst, a blocked sewer can back up into the property itself, which is as unpleasant as it sounds.

How aggressive roots are depends on the tree species and the location. Andy has a plumber friend on the Gold Coast whose business stays very busy just clearing roots from pipes.

Your Three Repair Options

Andy isn’t a plumber, but he’s discussed these options with several experienced plumbers. Always get advice and quotes from a licensed plumber.

Option 1: High-Pressure Jetting (Temporary Fix)

A plumber feeds a high-pressure water jetter through the pipe to cut out the roots.

• Pros: Quick, relatively cheap, clears the blockage
• Cons: It doesn’t fix the crack. Roots will grow back through the same opening

Treat this as a short-term fix while you plan a permanent one.

Option 2: Pipe Relining with a Sleeve (Least Invasive)

The pipe is cleaned out, then a liner or sleeve is fed inside the damaged section to seal it from within. Some newer systems are cured with UV light, so they set quickly and the pipe can be used almost straight away.

Andy compares it to heart surgery for clogged arteries: you fix the problem from the inside, without opening everything up.

• Pros: No digging or slab cutting, minimal disruption, quick turnaround
• Cons: Results depend on the plumber’s skill and experience

Indicative cost: around $3,000 for a single crack within about a 1 metre section. A longer damaged section, say over 5 metres, might cost a few thousand dollars more. It doesn’t scale up metre by metre. Price depends on the plumber, your location, access and pipe length.

This is the option Andy would look at first.

Option 3: Cut the Slab, Dig and Replace

The concrete is cut, the damaged pipe is dug out and replaced with new PVC pipe that roots can’t get into, and the slab is re-poured.

• Pros: Replaces the damaged pipe completely
• Cons: Invasive and time-consuming. Plumbing can’t be used during the work. There’s a risk of hitting other services such as gas, electrical or phone lines

Indicative cost: well over $3,000, and many plumbers won’t give a fixed price because digging under a slab involves too many unknowns.

Shop Around for Relining

“Not all sleeves are the same,” Andy says. Some plumbers are much more experienced at relining than others, so it’s worth comparing quotes and asking about their track record with this type of repair.

Frequently Asked Questions

How do I know if tree roots are in my sewer pipe?

Common signs include slow drains, gurgling, recurring blockages and sewage smells. A plumber can confirm it with a CCTV drain camera inspection.

Will jetting fix tree roots permanently?

No. Jetting clears the roots, but if the pipe is cracked, roots will grow back. You need to seal or replace the damaged section for a lasting fix.

How much does pipe relining cost?

As a rough guide, around $3,000 for a single crack in a short section, rising for longer sections. Get quotes from experienced relining plumbers.

Is pipe relining better than digging up the pipe?

For many situations, yes. It’s less invasive, faster and avoids the risk of damaging other underground services. Your plumber can advise whether relining is suitable for your pipe.

The Bottom Line

Tree roots in a sewer line are common, and on a strata property they can affect everyone in the building. Clear the blockage, then fix the crack properly. Get quotes from experienced plumbers and ask about relining first. Problems under a property, whether in drainage, the subfloor or the foundations, are easy to miss on a walk-through. A Swell inspection looks for the signs and points you to the right specialist when something needs a closer look.

Andy is a licensed builder with over 15 years of hands-on experience. Every Swell inspection comes with a plain-English report, usually within 24 hours, and a follow-up call to walk you through the findings.

Ready to book? Book your pre-purchase inspection or call 0483 935 688.