A Guide to Drain Relining

Table of contents

1. What Is Drain Relining?
2. How Does Drain Relining Work?
3. When Is Drain Relining the Right Solution?
4. When Is Drain Relining Not Suitable?
5. How Long Does It Take to Reline Drain Pipes?
6. How Much Does Drain Relining Cost?
7. Drain Relining vs Excavation: How to Compare the Options
8. How to Find a Drain Specialist
9. FAQs: Drain Relining

This guide covers how the process works, when it's the right fix and when it isn't, how long it takes, and what to expect on cost. So you can go into any conversation with a drainage specialist already knowing the right questions to ask.

What Is Drain Relining?

Drain relining is a method of repairing a damaged underground drain pipe by inserting a new lining inside it, without excavating the ground above it.

The technique is formally known as Cured-in-Place Pipe (CIPP) lining. It is a name that describes exactly what happens: a flexible liner, saturated with epoxy resin, is inserted into the damaged pipe and then cured (hardened) in place.

The result is a smooth, continuous, jointless surface inside the original pipe. Because the liner bonds to the existing pipe walls, it seals cracks, closes open joints, and creates a barrier against future root intrusion. All without disturbing the ground, the garden, the driveway, or any structures above the pipe.

The technique was invented in 1971 and has been used widely in UK drainage repair since the 1990s. Modern epoxy-resin liners have a documented service life of 50 years or more when correctly installed - comparable with new pipe replacement.

Find a plumber near you

How Does Drain Relining Work?

The process follows a consistent sequence regardless of which company carries it out. Understanding what happens at each stage helps you assess whether the work quoted is appropriate for your specific problem.

Step 1: CCTV Survey

No reputable drain relining company will begin work without first inspecting the pipe using a CCTV drain camera. The camera is fed into the drain from an inspection chamber or access point and travels the length of the pipe, recording footage on a monitor above ground.

This reveals the precise location and nature of the damage - cracks, open joints, root intrusion, partial collapse - and confirms whether the pipe's condition makes it suitable for relining. A CCTV survey also measures the pipe's diameter and length, which determines the specification of the liner needed.

Step 2: High-Pressure Jetting

Before the liner can be inserted, the pipe must be thoroughly clean. Any debris, root material, accumulated grease, or scale is removed using a high-pressure water jet.

Robotic cutters are used where roots or significant obstructions need mechanical removal. This step is critical, any debris left on the pipe wall prevents the liner from bonding properly.

Step 3: Preparing the Liner

The liner itself is a flexible tube made from felt, fibreglass, or a composite material. It's cut to length and saturated evenly with epoxy resin. The resin is mixed and rolled into the liner material, ensuring complete and even coverage.

Step 4: Insertion and Inflation

The resin-saturated liner is inserted into the pipe using one of two methods. In the inversion method, the liner is turned inside out as it's fed into the pipe using air pressure, ensuring the resin-coated face makes contact with the pipe wall throughout.

In the pulled-in method, the liner is drawn through the pipe using a winch and cable, then inflated with a bladder. Both methods ensure the liner conforms to the full internal profile of the pipe, including bends and changes in diameter.

Step 5: Curing

Once positioned and inflated, the liner is cured to harden the resin. Curing can be done with hot water, steam, or UV light depending on the specific liner system. UV curing is the fastest method, typically 15 minutes for a standard domestic drain run. Hot water curing takes one to four hours. Once fully cured, the bladder or inversion drum is removed.

Step 6: Post-Lining CCTV Inspection

A second CCTV inspection confirms the liner is correctly seated, fully bonded, and the pipe is performing as expected. Any openings for lateral connections (where subsidiary drains join the main pipe) are reopened using a robotic cutter if needed.

When Is Drain Relining the Right Solution?

Most drain problems look similar from the outside - slow drainage, a smell, a recurring blockage.

But the underlying cause determines whether relining is the right solution or whether something else is needed. Here's what relining actually fixes well.

• Cracks and fractures in the pipe wall. A cracked pipe leaks sewage into the ground and allows groundwater in, reducing the drain's capacity. Relining seals these cracks completely and restores structural integrity without replacement.

• Open or displaced joints. In older clay and concrete pipes, the joints between sections can open or become displaced over time, allowing leaks and root intrusion. Relining creates a continuous, jointless surface that eliminates this problem.

• Root intrusion. Tree roots entering through pipe joints or cracks cause progressive blockages and structural damage. After root removal using a robotic cutter, relining seals the entry point and prevents re-entry.

• General pipe deterioration. Older clay pipes in particular can become porous and structurally weakened over decades. Relining restores their structural integrity and extends the pipe's effective life by several decades.

• Patch repairs. Where only a specific section of a pipe is damaged, a patch liner (a short section of liner applied to a targeted area) can be used rather than lining the full length of the pipe - a faster and more economical option for localised damage.

When Is Drain Relining Not Suitable?

Drain relining is not a universal solution, and a specialist should tell you honestly when it's not appropriate and you may need a full drain replacement.

• Full pipe collapse. A pipe that has completely collapsed - lost its circular profile - cannot be relined, because the liner needs the existing pipe to provide its form during curing. A collapsed pipe requires excavation and replacement.

• Severe misalignment. A pipe that has dropped significantly or shifted out of alignment may not allow the liner to be inserted or may result in a liner that doesn't conform properly to the pipe walls.

• Pitch fibre pipes. Pitch fibre was used in UK drainage from the 1950s to the 1970s and tends to deform into an oval cross-section over time. Relining a deformed pitch fibre pipe with a standard circular liner results in a poor fit. Specialist liners exist for pitch fibre, but replacement is often more practical.

• Very short pipe runs. The economics of mobilising specialist equipment don't always make relining cost-effective for very short pipe sections - in these cases, targeted excavation and repair may be more practical.

Find a plumber near you

How Long Does It Take to Reline Drain Pipes?

One of the main practical advantages of drain relining over excavation is the speed of completion.

A standard domestic drain relining job - covering a typical residential drain run of 8-12 metres - can be completed within 4-6 hours in good access conditions.

This includes the CCTV survey, jetting, liner preparation, insertion, curing, and final inspection.

Longer runs, multiple access points, and use of hot water curing rather than UV curing extend this. A complex job covering 30+ metres of drain with multiple lateral connections might take a full working day.

This compares with traditional excavation and pipe replacement, which for a comparable run typically takes 2-5 days to excavate, replace, backfill, and reinstate the surface.

How Much Does Drain Relining Cost?

Drain relining typically costs around £70-£130 per linear metre for a 100mm diameter pipe, or £120-£170 per linear metre for a 150mm pipe.

For a typical domestic drain run of 8-12 metres, this equates to approximately £600-£1,500 for a standard 100mm soil drain.

Factors that affect the cost include:

• Pipe diameter - larger pipes require more liner material and typically larger access equipment
• Run length - longer runs cost more in total but the per-metre rate often reduces for longer jobs
• Degree of preparation needed - heavy root cutting or severe blockage removal before lining adds cost
• Access - difficult or deep access points add time and labour
• Liner type - UV-cure systems are faster but the equipment cost can be reflected in the price

A CCTV survey, typically £150-£350, is required before any relining work and is usually charged separately. Some companies include this in a combined survey-and-repair quote.

See the drain pipe repair cost guide for current pricing across all drain repair methods.

Drain Relining vs Excavation: How to Compare the Options

For drain problems that could be addressed by either relining or excavation, the choice comes down to cost, disruption, and the specific nature of the problem.

Relining is typically better when:

• The pipe is under a driveway, patio, garden, or structure that would be expensive and disruptive to dig up
• The problem is cracks, open joints, or root intrusion rather than structural collapse
• Speed of completion matters
• The pipe diameter and condition make it technically suitable

Excavation and replacement is typically better when:

• The pipe has fully collapsed and cannot be relined
• Access to the pipe is straightforward and reinstatement costs are low
• The pipe material (such as deformed pitch fibre) isn't well-suited to relining
• Other work in the same area makes excavation efficient to combine

A reliable drain specialist will offer both options where both are viable and give an honest comparison. Be cautious of any company that recommends relining without first conducting a CCTV survey, no reputable company should quote for relining without knowing the pipe's condition.

How to Find a Drain Specialist

You can find and compare available plumbers near you on MyBuilder who offer drain relining services. Post your job with details of the symptoms, slow drainage, recurring blockages, suspected pipe damage, or a previous survey report, and drainage specialists in your area will respond.

See the drain unblocking cost guide for wider context on drain repair and maintenance costs.

All tradespeople on MyBuilder undergo checks at registration, such as ID documents, company details, certifications for regulated jobs and skill assessments, allowing you to hire with confidence.

Find a plumber near you

FAQs: Drain Relining

How Long Does a Relined Drain Last?

A professionally installed epoxy resin drain liner has a documented service life of 50 years or more. The liner is resistant to corrosion, root re-intrusion, and chemical attack from standard sewage.

The longevity depends on correct installation - primarily, achieving a complete and even bond between the liner and the existing pipe wall, which is why the pre-lining jetting stage is critical. You can browse completed drain relining projects on MyBuilder to see what professional work involves.

Is Drain Relining DIY?

No. Drain relining requires specialist equipment, CCTV cameras, high-pressure jetting units, inversion drums or winch equipment, and UV or hot water curing systems, that are not practical for DIY use. The process also requires experience to correctly specify the liner, manage the curing, and reopen lateral connections. This is a job for a drainage specialist.

Can All Drain Materials Be Relined?

Most common drain materials - clay, concrete, PVC, cast iron - can be relined. Pitch fibre pipes can be relined with specialist liners but replacement is sometimes more practical.

Fully collapsed pipes cannot be relined regardless of material. A CCTV survey confirms which option is technically viable for a specific pipe before any work is committed to.

Will Drain Relining Reduce the Pipe's Flow Capacity?

Marginally - the liner has a wall thickness of 3-6mm, which slightly reduces the internal diameter. In practice, this reduction in diameter is offset by the smoother interior surface of the cured liner compared with the irregular or partially obstructed surface of an old, damaged pipe. In most domestic drain applications, relined drains flow better than damaged originals. See our guide to clearing blocked drains for more on what causes drain flow problems.

Does Drain Relining Require Planning Permission?

No. Drain relining is a like-for-like repair to an existing pipe and doesn't require planning permission or building regulations approval for standard domestic drains. If the drain is shared with neighbours or connects to public sewer infrastructure, the water authority may need to be notified, but this is typically handled by the drainage company.