vickey parchani
February 5, 2026
15 mins read

What is Pipe Relining?

All plumbing problems are annoying. But not many grind your gears like having to deal with random puddles in your yard because of a burst underground pipe.

This job has taught us something, though: no plumbing issues are isolated. Your negligence or actions, or natural causes (the intrusion of tree roots), did something to cause it.

Now, you’re thinking of how to find and fix the broken pipes underground, or you’ll turn your whole yard into a swamp.

Praise the plumbing lords for the magic of pipe relining.

So, what even is pipe relining?

As alluded to earlier, this simply means fixing an underground pipe without doing any digging. The pipe relining specialist first inserts a drain camera to find where the leak is, before inserting the liner. The liner is coated with epoxy resin, which hardens after a while of application, forming new, stronger pipe walls.

Professional plumbers call it cured-in-place pipe relining (CIPP relining). Some others call it drain relining or trenchless pipe relining. It’s like slipping a pipe within a pipe, so that you can enjoy your piping system for longer.

Pipe Relining: A Trenchless Underground Relining Solution

Trenchless Underground Relining Solutions are a way to fix sewer pipes, stormwater drains, and any plumbing system that runs through the ground.

With these solutions, the plumbing companies contracted to work will use the available access holes to the underground plumbing instead of digging up a property yard or the whole neighbourhood.

As fun as this sounds, though, if your piping structure isn’t solid, you won’t be able to enjoy CIPP relining services. That is why the plumber has to inspect the pipes using a drain camera first. This is mainly to find out if it is safe to try pipe relining solutions or if the whole thing should be dug out, redone, and relaid.

Whatever their CCTV cameras show them is what they work with. If their CCTV cameras show that there is no need to excavate, the plumber sets to work.

The first step in the relining process is to clean out the pipes with a high-pressure water jet. If there is any debris or clog in the pipe, they won’t survive the jet.

The next step is to slide the epoxy resin-coated liner into the pipe. Once it’s inside, the plumber will inflate it, allowing the resin to adhere to the pipe walls. After a while, they slowly remove the liner and use UV light or a heat source to cure (harden) it. If there are any side branches from the epoxy, the plumbers use a small lateral CIPP packer or a remote cutter to chop them off.

If you know how hard epoxy can get, you will understand the appeal of the pipe relining process. The new inner pipe that forms from this method tends to be stronger than the original pipe, meaning that your sewer line or water piping system can last decades longer!

Pipe Relining Solutions: Why Trenchless Is Changing the Game

Everything described in the previous sections still feels like magic. But that is how innovation feels. Like magic.

When something new, groundbreaking and efficient comes in to replace a method that has existed for ages, it feels surreal. This feeling is even deeper if that innovation saves time and resources while solving the problem and achieving the end result.

In the old days, fixing any broken drain or sewer pipe was brutal: you needed to dig.

In the time before excavators, plumbers would dig up the earth with shovels, pickaxes and diggers. Then they’d have to bring out the affected pipe, replace or reline it, lay it back in the trench, and then replace the earth they dug up.

Your landscaping suffers as a result, which will cost you even more money to redo.

The relief that trenchless pipe repair (especially trenchless pipe relining) brought to property owners and plumbers was immense.

With this method, the toughest fixes will still not require full excavation. Instead, the plumbing companies that specialise in this service will make small pits to help with visibility.

This meant your yard, flower beds, sidewalks, or porches suffered little to no damage. If your issue was serious enough to dig up sections of the block, this method makes sure you don’t have to. There is absolutely no need for the “construction work” that its predecessor method needed.

This also translated to time and cost savings. If you have to dig up the whole yard or the whole block for pipe patching works or sewer relining, you would be spending a lot of money and time. When the work is done, you will also spend a lot of money and time on restoration, as mentioned earlier.

Granted, different plumbing companies charge differently for pipe rehabilitation works. However, the cost of trenchless solutions is way less than the cost of having to dig trenches to fix your drain pipes or water pipes. What took weeks now takes days.

The paragraphs above also show that trenchless underground relining solutions work for any plumbing that runs underground.

As a solution, it is mostly geared towards sewers, but you can use this to fix your storm drains and water lines, too. Big municipal plumbing fixes have been done with cured-in-place pipe relining.

The best part of this innovation, like any other, is its evolution. Relining solutions and relining technology are not what they used to be a decade ago. There are now faster and more seamless ways to carry out CIPP relining and any other underground pipe work.

Different systems, such as the Brawoliner system, Perma-Liner system and so on, have also been conceived to tackle underground pipe works. Some plumbing companies have even carved a niche for themselves in this regard by coming up with their own pipe relining system and selling it to tradesmen.

Saving time, cost, resources, and your yard, as well as being able to deal with any underground plumbing issues, is why trenchless is a game changer.

Common Causes of Pipe Damage

Necessity is the mother of invention, it is said. A problem must happen before a solution is innovated.

All the talk about pipe relining won’t have happened if pipes didn’t get damaged after being laid underground and away from human interaction (because we tend to ruin things as a species).

So, what damages these pipes underground?

Age and corrosion:

Barely anything in this world escapes the effects of time. All materials degrade. Steel pipes, copper pipes, pipes made from other types of metal, or even porcelain pipes, all degrade the older they get. The ageing and corrosion happen faster if the soil beneath which they’re buried is acidic or if the groundwater is hot.

Tree roots

If you live in a neighbourhood with trees, good for you! You are probably enjoying better air quality than most. Unfortunately, this is not good for your underground plumbing. If your plumbing is old, the pipe walls become weak. If the pipe walls become weak, the moisture starts to seep out a little. Tree roots will be attracted to the moisture and attack your pipes to access it, causing breakages and blockages.

Ground movement:

The earth beneath your feet is always moving, sometimes naturally and other times because of the traffic above it. When this movement happens, the soil around the pipes can shift them out of alignment. This can sometimes lead to cracks or breaks that need fixing.

Blockages:

This is entirely a man-made issue. When you flush the wrong things down your toilet, when you pour grease that hardens into fatbergs down your kitchen sink, when you allow sand and litter into your stormwater drains, and when you deliberately allow debris to go into your drains, you’re setting yourself up for problems. Over time, the pipes will get blocked, and the blockages can get big enough to crack the pipes.

We mentioned earlier in the blog that this job has taught us that plumbing issues are never isolated. Now, you know why the first-ever pipe relining discourse first happened, which has led to the amazing innovations in trenchless underground pipe relining technology we have today.

Traditional Replacement vs Modern Trenchless

Before we go on, we need to emphasise that the classic pipe relining method is still very much in use today. It is the only option in many cases, in fact.

Some of the cases where it is especially recommended are:

When the structural strength of the plumbing system cannot be easily ascertained with a CCTV camera inspection.
When the inspection reveals crushed sections of the plumbing system.
When the pipe has “bellies”, which are sagged sections that collect standing water and debris.
When the different joints of the pipes are broken due to earth and soil movement.
When the pipes are made of certain materials or if they’re banded together with certain materials.
When the plumbing system is especially complex, i.e. when there are so many twists and turns and complex junctions.
When the plumbing system is shallow and in an open area, for example, two to three feet beneath the ground in a park or in a yard with no structures or trees above it.

Trenchless systems still exist to deal with some of the scenarios described above, however. No diggers, pickaxes or excavators, just a straightforward insertion of an inflatable liner that coats the pipe walls with epoxy resin (or a similar material), which hardens into a new pipe.

Also, as mentioned earlier, to navigate around some of these complexities, small holes will be dug around the system. This aids the specialist to see beneath the ground and adapt his fixes.

The pipe relining specialist will have to inspect (diagnose) the damage, however, to decide on the method to use.

The Pipe Relining Process

This is the full breakdown of the process of relining a pipe if trenchless relining is chosen as the way to go:

Cleaning

The relining specialist will clean out the pipes first with a high-pressure water jet.

Liner Insertion:

The specialist will thread a liner (usually made of fabric) that has been soaked in epoxy resin, polyester resin, or a similar material into the pipe from an opening. Once the liner has reached the location to be fixed, they’ll either pull it out or invert it. If they invert it (known as inversion CIPP relining), an already-set-up inversion drum at the opening will inflate the liner with water or air. This pushes the liner further down the pipe and also allows it to coat the walls of the pipe with the resin.

Curing:

Once the coating is done, the resin will be cured with heat (steam or hot water) or with a powerful UV lining system. Once it hardens, you will have a pipe within a pipe.

Reconnecting Branches:

Once the resin hardens following the curing process, the specialist will reconnect the system’s branches. Then they’ll use a lateral CIPP packer to cut out any strays and to remove the liner fabric where needed.

Final Inspection:

This goes without saying, as every job that has been completed needs one final check to be certain. The drain camera will be put to use again to confirm a job well done.

What To Look Out For

If they pitch trenchless solutions to you, there are some things you have to confirm with the company or the team first.

Trenchless underground relining solutions are a speciality area in plumbing. Your trusted plumbers who have handled your property for decades may not be qualified enough to handle this type of work. Find out their qualifications, experience and if they have insurance (this is very important!) first before you allow them to work on your pipes.

After this, find out if they have documented past work. Get them to show you some of these works, so that you can ascertain their experience for yourself. Ask for before and after videos, and also ask them to document the work they’re doing on your pipes. This will help you if you have to file claims later.

The next is the diagnosis. A reputable plumber will always inspect with a camera first and show you the sections that need fixing. If you didn’t see them inspect the pipes, insist that they do.

The final thing you need to confirm is the materials they want to use. Liners are mostly fabric-based, but there are liners made of fibreglass and PVC in the market too. Find out what the liners are made of, how they’re cured and why they were chosen for the job.

One of the reasons this is important is that some liners do not do well in certain local conditions. For example, if the groundwater in your area is high, or your plumbing systems have quite a few bends and curves, certain liners may not work well for them.

It is a huge red flag if a tradesman is being pushy about doing trenchless relining. It is an even bigger red flag if they cannot provide you with answers to any of the issues in the previous paragraphs under this section.

Benefits of Relining

Structural strength:

The epoxy or polyester resin that coats the liner fabric or fibreglass is actually tougher than most materials from which pipes are made. For one, epoxy or polyester does not corrode or crack easily. When it hardens within the pipe, together with the liner, they add structural strength to the pipe, extending its lifespan.

Seamless protection:

Laying pipes means making joints, corners and curves, which create seams. This means you have to cut pipes to certain lengths and attach them using elbows and sockets. When fixing broken underground pipes with liners, you eliminate the need for seams or joints. When the liner hardens into a new wall, all the seams will be closed, and there will be little to no space for invasions or leaks.

Quicker return to service:

Choosing the relining process over digging a trench means that you get your plumbing up and running faster. Relining jobs are typically completed within a day or two, unlike trench digging, which could take weeks to fix.

Environmentally friendlier:

Digging trenches to fix broken pipes means digging up the earth. This is basically messing with the environment. You’ll move soil, uproot some plants, and possibly even cut through tree roots. Relining eliminates this part of the underground pipe rehabilitation process. Relining also makes sure that your plumbing system stays stronger for longer, eliminating the need for future materials and work.

Cost savings over time:

Following from the last point, the fact that relined pipes last longer means that you do not have to plan towards any major fixes in the near future. In fact, it could take decades before you have to do another relining, even if you carelessly clog the sewers. This saves you maintenance money in the long run.

Conclusion

Pipe relining, particularly CIPP relining, is one of many trenchless underground relining solutions that exist. The others are:

Sliplining: A plumber slips a smaller pipe into the damaged one, and fills the space between the walls of the new and old pipe with mortar.
Pipe Bursting: The plumber digs a small hole to blast away the damaged pipe. Then the plumber slips a new one into the space left behind and seals it.
Spray-in-Place Pipe (SIPP)/Coating: A plumber-controlled robot is sent into the pipe to spray the coating resin on its walls. The resin is then cured with heat, which hardens along the damaged pipe walls to seal them.
Fold-and-Form (Thermoformed) Lining: This method is like CIPP relining, but instead of a liner soaked in a resin, the plumber will insert a new pipe made of PVC that has been squished into a “C” shape. Once at the location, the plumber heats up the pipe until it expands to cover the walls of the already existing pipe.
Spiral Wound Lining: A plumber-controlled robot goes into the drain, winding a continuous strip of PVC that will eventually become a pipe within a pipe.
Mechanical Spot Repair (Sectional Lining): A plumber positions a patch over the leak and expands it with heat or UV lining until it seals the crack.

Some of the aforementioned are for commercial plumbing purposes only. The choice of whether to go with them or not is up to the client, upon the plumber’s recommendation.

You do not have to dig up your yard for underground plumbing fixes anymore, thanks to this technology.

If you’re dealing with a burst underground drain, contact Plumber Sydney today. We constantly carry out training sessions for our plumbers to ensure that they stay up to date with the latest in trenchless relining solutions. This is our assurance of the highest quality.

Pipe Relining: Repair Damaged Pipes Without Digging Up Your Yard

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