What Is Pipe Relining? Process, Costs & When You Need It
Pipe relining has become a popular solution for homeowners dealing with recurring drain and sewer pipe problems, and for good reason. Instead of digging up your yard, driveway, or floors to replace damaged pipes, plumbers can repair them from the inside using a trenchless method that is faster, less disruptive, and often more cost-effective. But while pipe relining offers clear advantages, it’s not always the right fix for every pipe problem. Factors like the pipe’s condition, alignment, and overall structure can sometimes disqualify you for relining, and in those cases, complete replacement is often a better option. This guide explains everything you need to know about pipe relining, including how the process works, when it’s suitable, what it typically costs, and when a full pipe replacement may make more sense. TL;DR What Is Pipe Relining? Pipe relining is a trenchless, non-invasive method to fix damaged sewer and drain pipes. Instead of tearing up your yard, driveway, or floors, plumbers insert a resin-coated liner into the existing pipe. Once it hardens, it forms a strong, seamless pipe within a pipe that can last 40–60 years. It’s commonly used to stop leaks, block tree roots, and improve slow drains without the mess and cost of traditional excavation. In Townsville, this method is especially useful because many older homes have earthenware or early PVC pipes joined in sections. During the wet season, soil shifts and tree roots can push into these joints, causing cracks, leaks, and blockages. Relining solves this by creating a continuous, joint-free inner pipe, so roots can’t get in, and your plumbing flows smoothly. How Pipe Relining Works: What Happens Step by Step 1. CCTV Inspection and Damage Assessment The first step is to inspect the inside of the pipe using a specialised drain camera to see exactly what’s wrong and confirm whether relining will work. Here’s what the technician does during the inspection: In these cases, excavation and pipe replacement may be required. 2. High-Pressure Cleaning and Pipe Preparation Once the CCTV inspection confirms the pipe is suitable for relining, the next step is to thoroughly clean and prepare it. Any grease, roots, or mineral buildup left inside can stop the resin from bonding properly, so the pipe must be cleared before the liner goes in. Here’s how plumbers get it ready: 3. Measuring the Pipe and Preparing the Liner Once the pipe is clean and ready, the plumber prepares the liner, which is the material that will become the new pipe inside the old one. Here’s what happens: 4. Installing the Liner Inside the Pipe Now it is time to insert the resin-soaked liner into the existing pipe. Plumbers typically use one of two methods, depending on the pipe layout and access points. 1. Inversion method (turned inside out into the pipe) In this method, the liner is placed into a pressurised container called an inversion drum. Compressed air or water pushes the liner into the pipe while turning it inside out as it moves forward. Inside out means the resin-coated side of the liner, which will form the new pipe wall, ends up pressed against the inside of the old pipe, while the plain side faces the centre. This method is especially useful for pipes with bends, because the pressure helps the liner bend and follow the curves without wrinkling or folding. 2. Pull-in-place method For straight pipes or small repairs, a cable or winch line is first fed through the pipe. The prepared liner is attached to this cable and pulled into the exact position where the damage is located. Once the liner is in place, the plumber uses the CCTV camera to confirm the liner is positioned correctly and fully covering the damaged section before the curing process begins. 5. Inflating the Liner to Shape the New Pipe Once the resin-soaked liner is in place, it needs to be pressed firmly against the inside of the old pipe so it forms a strong new pipe wall. Plumbers do this by inserting a long inflatable tube, called a calibration tube or bladder, inside the liner. Compressed air or water is pumped into the tube using specialised equipment on the truck at the work site. As the bladder inflates, it pushes the liner tightly against the pipe walls, ensuring the resin spreads evenly and seals all cracks and damaged joints. 6. Curing the Resin With the liner held tightly in place, now it is time to turn the liquid resin inside the liner into a strong, solid pipe lining. In warm climates like Townsville, the resin can sometimes cure naturally over a few hours because higher temperatures speed up the hardening process. However, to complete the job faster and more reliably, plumbers often circulate hot water or steam through the inflated bladder. The added heat helps the resin cure evenly along the entire length of the liner. Once curing is complete, the liner hardens into a rigid, seamless pipe inside the old one. The original pipe becomes a protective shell, while the newly cured lining carries the wastewater flow. 7. Reopening Branch Connections After the new liner is in place, it covers the points where smaller pipes – from toilets, showers, or sinks – connect to the main sewer line. These connections need to be reopened so water can flow from every fixture. Plumbers do this using a small, remote-controlled cutting tool with a camera. The technician navigates the tool to each connection using the CCTV footage and locations from the initial inspection. The cutting head then precisely opens a hole in the liner that matches the size of the branch pipe. This restores the connection while keeping the inside of the pipe smooth and even, so wastewater flows freely without getting caught on rough edges. 8. Final CCTV Inspection and Verification After the new liner is cured, plumbers perform a final CCTV inspection to make sure the repair is done correctly. A camera is sent through the full length of the pipe to check that
