It’s a reasonable question. If you’re already spending money to reline a pipe, why would you need to spend more on robotic cutting first? Isn’t relining the fix?
Yes, but relining only works if the inside of the pipe is in the right condition for a liner to bond to. If there are roots, broken joint lips, misaligned sections or chunks of hardened scale sitting in the pipe, the liner can’t seat properly. You end up with bulges, gaps, or sections that don’t cure correctly. The reline fails or doesn’t last as long as it should.
Robotic cutting is how we prepare the pipe before the liner goes in.
What robotic cutting does
A small, remotely operated cutting unit is fed through an existing access point. No digging required. The operator watches a live camera feed and uses the robot’s cutting head to precisely remove whatever’s blocking or protruding inside the pipe.
That might be:
Tree roots that have grown through pipe joints and established themselves inside the drain. High-pressure jetting can break up soft root growth, but mature root masses need mechanical cutting to remove them properly.
Joint lips, where a pipe section has shifted or cracked slightly, leaving a raised edge that sticks into the flow path. Left in place, that edge stops the liner from sitting flush against the pipe wall.
Scale and calcite buildup, particularly in older clay or cast-iron pipes, which can be hard enough that jetting alone won’t shift it.
Our cutting heads handle pipes from 75mm to 300mm in diameter, which covers most residential and light commercial drainage.
Here’s the key point: robotic cutting removes whatever would stop a liner from bonding properly. It’s precision prep work, not an add-on.
So, when do you need both?
Not every pipe relining job requires robotic cutting. If the pipe is cracked or structurally compromised but the interior surface is clean and clear, the liner can often go straight in after jetting.
- But if a CCTV inspection picks up any of the following, cutting comes first:
- Tree roots that haven’t been fully cleared by jetting
- Displaced or misaligned joint sections with protruding edges
- Solid intrusions or heavy scale deposits
- Any surface irregularity that would stop the liner lying flat
We assess this during the initial CCTV inspection. If the pipe needs cutting, we’ll tell you before we quote the reline, not after.
Here’s the key point: whether you need robotic cutting is determined by what the camera finds. We won’t recommend it unless the inspection shows it’s necessary.
How long does the combined process take?
Robotic cutting alone typically takes 2 to 4 hours depending on the length of pipe and the severity of the obstruction. When it’s combined with relining, the full job usually takes a day. No excavation, no reinstatement, no garden or driveway to repair afterwards.
Once the cutting is complete, we do a follow-up CCTV pass to confirm the pipe walls are clear and intact before the liner goes in. That second inspection is what gives us confidence the reline will hold.
From the homeowner’s side, a combined cutting and relining job looks like this: the crew arrives, they camera the pipe, cut what needs cutting, camera it again, install the liner, cure it, and camera it one final time. Most of that happens in the background. You’re not dealing with excavators or concrete cutters. The job is self-contained.
Here’s the key point: cutting plus relining is typically a one-day job with no digging. Three CCTV checks are done throughout, at inspection, after cutting, and after relining.
Why this matters for the liner’s lifespan
A properly installed liner in a prepared pipe should last 50 years. That number assumes the liner has made full, even contact with the host pipe the whole way along.
Skip the cutting step on a pipe that needs it and you’re likely looking at a liner that bonds inconsistently. It may hold for a while, but you’re reducing the working life of the reline significantly, which undermines the whole point of doing it.
The goal is to do the job once and have it last. Robotic cutting is how we make sure that’s what happens.
Here’s the key point: a reline is only as good as the surface it bonds to. Cutting ensures that surface is right. Skipping it on a pipe that needs it shortens the liner’s life considerably.
Frequently asked questions
Is robotic cutting always needed before relining?
No. If the CCTV inspection shows the inside of the pipe is clear and even, the liner can go straight in after high-pressure jetting. Robotic cutting is only recommended when the inspection finds roots, raised joint edges, scale or other obstructions the liner can’t seat around.
Will robotic cutting damage my pipes?
No. That’s the point of remote operation and live camera monitoring. The operator can see exactly what they’re cutting and controls the tool precisely. Only the obstruction is removed. The pipe wall itself is left intact, which is confirmed by the CCTV check done immediately after cutting.
Does robotic cutting require digging?
No. The cutting unit is fed through an existing access point, the same way a drain camera is. No excavation, no jackhammering, no landscape reinstatement. It’s a trenchless process from start to finish.
Can robotic cutting fix a blocked drain on its own, or does relining always follow?
Robotic cutting can clear an obstruction without relining following. If the pipe is structurally sound and the only problem is a root mass or heavy scale deposit, cutting alone may resolve the blockage. Relining is recommended when there’s structural damage, such as cracks, joint failure or corrosion, that the pipe can’t recover from on its own.
How do I know if my pipe needs robotic cutting?
You won’t know until a CCTV inspection has been done. The camera footage shows exactly what’s inside the pipe, including root growth, joint condition, surface quality and structural damage. From there, we can tell you what the pipe needs and gives you a clear quote before any work starts.
Talk to us about your pipe
If you’re dealing with a blocked or damaged drain, the first step is a CCTV inspection to find out what’s going on inside. From there, we’ll tell you whether you need pipe relining, robotic cutting, or both, and give you a straight quote before any work starts.
Get in touch with Green Planet Plumbing to book a CCTV inspection in Newcastle or Lake Macquarie.