How Pipe Relining Works: A Step-by-Step Guide for Newcastle Homeowners

The idea of fixing a broken underground pipe without digging up your yard sounds almost too good to be true — but pipe relining is a well-established, proven technology that has been used in Australia for over 20 years. For Newcastle homeowners dealing with cracked, root-invaded or deteriorating drainage pipes, it offers a permanent fix that's typically faster, cheaper and far less disruptive than traditional pipe replacement.

This article explains exactly how pipe relining works from start to finish, what you can expect if you have the work done, and how to know whether your pipes are suitable candidates.

What Is Pipe Relining?

Pipe relining — technically called Cured-In-Place Pipe lining (CIPP) — is a trenchless rehabilitation method that creates a new pipe within your existing damaged pipe. A flexible liner saturated with structural epoxy resin is inserted into the damaged pipe, inflated to press against the pipe walls, and then cured (hardened) in place using UV light or hot water. The result is a structurally sound, seamless tube that restores the original function of the pipe and seals all cracks, fractures and joints where roots previously entered.

The finished liner is rated for 50+ years of service life and carries a 35-year manufacturer warranty. In most cases it's stronger than the host pipe it's lining.

Step-by-Step: The Pipe Relining Process

Step 1: Initial CCTV Camera Inspection

Before any relining work can begin, your plumber will run a CCTV drain camera through the entire pipe section to be treated. This is non-negotiable — relining without knowing the full condition of the pipe would be like painting over rust without treating it first.

The CCTV inspection reveals:

• The exact location and extent of any cracks, fractures or joint separation
• Whether tree roots have entered and how established they are
• The pipe diameter and any diameter variations along the run
• The pipe material (terracotta, concrete, PVC, cast iron)
• Whether the pipe structure can support a liner (critically — a fully collapsed section cannot be relined)
• The total length of pipe to be treated

You can watch the inspection footage in real time on the monitor. Your plumber will explain what they're seeing and advise on the most appropriate solution.

Step 2: High-Pressure Jet Cleaning

Before the liner goes in, the pipe must be thoroughly cleaned. All tree roots, accumulated grease, debris, scale and loose material must be completely removed. Even small amounts of residue can prevent the resin liner from bonding properly to the pipe wall, creating voids that compromise the seal.

The pipe is jetted at high pressure using a root-cutting nozzle to remove any root mass, followed by a full pipe-wall clean. This preparation step typically takes 30–60 minutes and is usually included in the relining quote.

Step 3: Liner Preparation

The correct liner size is selected based on the pipe diameter measured during inspection. A felt or fibreglass tube is saturated with two-component structural epoxy resin — the compound that will cure into the rigid new pipe wall. The saturated liner is kept cool until installation to prevent premature curing.

Step 4: Liner Installation

This is the "trenchless" part. The resin-saturated liner is inserted into the pipe through an existing access point — a cleanout, inspection shaft, drain opening or, in some cases, a small excavated access pit (usually no larger than 300–400mm wide). No digging of the pipe run itself is required.

The liner is positioned carefully using CCTV guidance to ensure it covers the full length of the damaged section, with overlap at each end onto sound pipe to create a complete seal. Getting positioning right is important — once the resin cures, the liner is permanent.

Step 5: Inflation and Curing

Once positioned, an inflation bladder inside the liner is filled with air or water to expand the liner outward, pressing it firmly against the entire pipe wall. Proper contact between the liner and the host pipe is essential for a complete seal — any gap creates a potential void.

The curing method used depends on the liner material and resin type:

• UV curing: A UV light train is pulled through the inflated liner, activating the resin and curing it from the inside out in one continuous pass. Curing time is typically 20–40 minutes.
• Ambient/hot water curing: Hot water or steam is circulated through the liner to cure the resin. This method takes longer (60–90 minutes) but is used for larger diameter pipes or where UV equipment isn't suitable.

Once cured, the resin forms a rigid, glass-smooth structural tube. The inflation bladder is removed, leaving the cured liner permanently bonded to the host pipe.

Step 6: End Trimming and Final Inspection

The ends of the cured liner are trimmed precisely at junction points and connections. Any lateral connections (branching pipes) that were covered by the liner are reinstated by cutting through from inside using a robotic cutter.

A final CCTV camera pass is then made through the completed liner to confirm it's correctly seated, fully sealed, and free of voids, wrinkles or defects. You're shown the post-installation footage alongside the pre-installation footage so you can see the difference directly.

What the Finished Liner Looks Like

Before relining: cracked terracotta joints with root masses visible, rough pipe walls, partial blockages. After relining: a smooth, uniform, dark-coloured tube running through the old pipe. The interior surface is noticeably smoother than even new PVC — which actually improves flow characteristics compared to the original pipe. The roots are sealed out permanently.

How Long Does Pipe Relining Take?

For a typical residential drain run in Newcastle:

Job Size	Total Time
Short section (up to 6m)	3–5 hours
Medium run (6–15m)	Half day to full day
Long run or full lateral (15m+)	Full day to 2 days
Complex layout (multiple junctions)	1–2 days

You can generally remain in the home during the work, though you'll need to avoid using the specific drain being relined for a few hours while the resin cures.

Pipe Relining in Newcastle's Older Homes: Why It's the Right Solution

Newcastle's heritage suburbs — Hamilton, Cooks Hill, Islington, Adamstown, Wallsend, Merewether, and inner Maitland — contain significant proportions of pre-1960s housing with original terracotta drainage systems. These pipes are increasingly at the point where root intrusion and structural degradation make annual jetting unsustainable as a long-term strategy.

The key advantage of relining for heritage properties is that it works without any excavation. Hamilton and Cooks Hill in particular have properties with tiled courtyards, heritage driveways, established gardens and slab-over pipes that would require significant structural disturbance to excavate. Relining eliminates this entirely — the pipe is fixed from the inside, with no surface disturbance beyond the small access point.

For investment properties across the Hunter region, relining also provides a clean, documented repair that can be shown to prospective buyers or tenants as evidence of a resolved infrastructure issue.

How to Know If Your Pipe Is Suitable for Relining

The CCTV inspection will confirm suitability definitively, but these factors are generally positive indicators:

• The pipe still holds its shape — no complete collapses
• The pipe diameter is consistent — severe joint displacement can prevent proper liner seating
• The pipe run has accessible entry and exit points
• The damage is cracking, root intrusion or joint separation — not chemical deterioration of the full pipe wall

And these factors may indicate that relining is not suitable:

• Complete pipe collapse over a significant section — excavation required
• Severely misaligned joints with more than 30 degrees of angular displacement
• Very short pipe sections where the liner can't be properly positioned and anchored
• Pipes with extreme chemical corrosion that has compromised the full wall thickness