Pipe Relining vs Pipe Replacement: Full Cost Comparison
When your drain pipes are damaged, you have two choices: reline them from the inside or dig them up and replace them. Here is an honest comparison of cost, time, disruption, and longevity.
Pipe relining costs $4,000-8,000, takes 1-2 days, requires no trenching, and preserves your garden and driveway. Pipe replacement costs $8,000-20,000, takes 3-7 days, and involves full excavation. Both have a 50-year design life. Relining is suitable for cracked pipes, root intrusion, and open joints. Replacement is necessary for fully collapsed pipes, severe bellies (sagging), or pipes that are undersized for current demand. Relining is the right choice for 80% of residential pipe repairs on the Northern Beaches.
- • Relining: $4,000-8,000, 1-2 days, no trenching, preserves landscaping.
- • Replacement: $8,000-20,000, 3-7 days, full trench, restores gardens after.
- • Both have a 50-year design life — same longevity.
- • Relining works for 80% of damaged pipes — cracked, rooted, open joints.
- • Replacement needed for collapsed pipes, severe bellies, or wrong pipe grade.
- • No council approval needed for relining; replacement usually does.
Full comparison table
Across Mosman, Manly, Dee Why, and Brookvale, here is how the two options stack up:
| Factor | Relining | Replacement |
|---|---|---|
| Upfront cost | $4,000-8,000 | $8,000-20,000 |
| Warranty / lifespan | 50 years (design life) | 50+ years (new PVC pipe) |
| Excavation required | Minimal — 1-2 access pits | Full trench — entire pipe length |
| Time to complete | 1-2 days | 3-7 days |
| Landscape disruption | Low — lawns, driveways, gardens preserved | High — full trenching destroys gardens, paths, driveways |
| Pipe material after repair | Epoxy liner inside existing pipe | New PVC or polypropylene pipe |
| Suitable for | Cracked pipes, root intrusion, open joints, moderate corrosion | Collapsed pipes, severely corroded, bellied (sagged) pipes, wrong grade |
| Council approval needed | Usually not required (same pipe, same path) | Usually required (new pipe in ground) |
When to choose relining
Pipe relining is the right choice when:
The pipe is cracked, has open joints, or has moderate root intrusion.
The pipe is structurally sound enough to support the liner (confirmed by CCTV).
You want to avoid excavating established gardens, driveways, or paving.
You are on a tight timeframe — relining takes 1-2 days versus 3-7 for replacement.
You want to avoid council approval processes and neighbour disruption.
Your property has limited access for excavation equipment.
When replacement is necessary
Despite the advantages of relining, replacement is the only option when:
The pipe has fully collapsed — no open lumen for the liner.
The pipe has a severe belly (sag) where water pools and debris settles.
The pipe is severely corroded internally with thinned walls.
The existing pipe is undersized for current demand (e.g., 80 mm pipe serving a 5-bedroom home).
The pipe grade is incorrect (too flat), causing ongoing blockages regardless of pipe condition.
There are multiple sections of damage that would require long lengths of relining, making replacement comparable in cost.
When to call a plumber
If your drains are damaged and you are deciding between relining and replacement, the first step is always a CCTV inspection. The camera footage will tell us whether your pipe is suitable for relining or if replacement is the only option. We will walk you through the footage, explain both options with clear pricing, and give you our honest recommendation — not the one that makes us the most money.
Book a CCTV inspection and we will assess your pipe condition and provide a fixed-price quote for the best solution.
Northern Beaches considerations
Pipe relining is particularly popular on the Northern Beaches because many homes have limited access for excavation equipment. Properties in suburbs like Mosman, Manly, and Brookvale often have sewer lines running under established gardens, paved driveways, or narrow side access. Relining avoids destroying these improvements.
The majority of our relining jobs are on homes with original clay pipes from the 1950s-70s. These pipes are typically cracked at the joints with tree root intrusion — an ideal candidate for relining. The epoxy liner bridges the cracks, seals the joints, and prevents future root entry.
Before committing to either option, we always CCTV inspect the full pipe length. If you are within 1 km of the coast in Dee Why or Narrabeen, we also check for saltwater infiltration that may have accelerated pipe deterioration. Contact our team to discuss your pipe repair options.
Frequently asked questions
How long does pipe relining last?
The epoxy liner has a 50-year design life. It is structurally independent of the old pipe — once cured, it is a new pipe inside the old one. Unlike the original pipe, it has no joints and is immune to root intrusion and corrosion.
Can any pipe be relined?
Most residential pipes can be relined, provided they are not fully collapsed or severely bellied (sagged). The pipe must be accessible from at least one end and clean enough for the liner to bond. A CCTV inspection confirms suitability before any decision is made.
Does pipe relining reduce pipe diameter?
Yes, slightly. The liner is typically 3-5 mm thick per side, reducing internal diameter by 6-10 mm. For a standard 100 mm sewer pipe, this is negligible and does not affect flow. For smaller pipes (50 mm), the liner may be proportionally larger and a plumber can advise.
Will my insurance cover pipe relining?
Most standard home insurance policies do not cover pipe relining or replacement — it is considered maintenance. Some policies offer optional sewer line coverage. Check your policy or speak to your insurer. The cost of relining is typically 40-60% less than replacement and may be more affordable out of pocket.
Not sure whether to reline or replace?
We will CCTV inspect your drains and give you a clear recommendation with fixed pricing for both options. No pressure, just honest advice.
Related reading
- CCTV Drain Inspection: When Do You Need One?— The first step before any pipe repair decision.
- Are Chemical Drain Cleaners Safe? (What Plumbers Say)— Why chemicals can make pipe damage worse.