Drain Relining vs Excavation: Which Repair Is Right?

Drain relining repairs a cracked, leaking or root-damaged pipe from the inside by curing a resin-soaked liner in place, usually without any digging. Excavation means digging down to the pipe and replacing the damaged section. Relining is quicker and far less disruptive where the pipe still holds its shape; excavation is needed where the pipe has collapsed, is badly deformed or was laid at the wrong fall.

What is drain relining?

Drain relining, often called cured-in-place pipe (CIPP) lining, forms a new pipe inside the old one. After the drain has been cleaned and inspected, a flexible liner soaked in resin is pulled or inverted into position and held against the pipe wall, usually by an inflatable bladder, until the resin hardens. The result is a smooth, jointless pipe inside the existing one.

There are two main types:

• Patch repairs – a short sleeve of liner cured over a single crack, open joint or point where roots got in.
• Full-length relining – a continuous liner from one access point to the next, used where defects are spread along the run.

Because the liner goes in through existing manholes or access points, there is normally no need to lift a driveway, patio or kitchen floor.

What does excavation involve?

Excavation is the traditional repair. The engineer digs down to the pipe, removes the damaged length, lays new pipe on proper bedding at the right gradient, tests it, backfills the trench and reinstates the surface. It takes longer and causes more disruption, but it can fix problems a liner can't, such as a pipe that has collapsed, sunk or been laid with a backfall.

Depth and location drive the cost. The deeper the pipe and the harder the surface above it, the more work is involved, and a pipe under an extension or a block-paved drive adds significant reinstatement.

When is relining not suitable?

A liner follows the shape and line of the existing pipe, so it can't correct problems with either. Relining is usually the wrong choice when:

• the pipe has collapsed or has missing sections, leaving nothing to line against;
• the pipe is severely deformed, for example flattened pitch fibre that can't be re-rounded;
• joints are heavily displaced, leaving a step the liner can't bridge;
• there is a backfall or sag where water sits, which a liner won't cure;
• the drain needs a new route, a larger diameter or a new connection.

Pitch fibre pipes, used widely on estates built between the 1950s and 1970s, need extra care. Industry guidance says they tend to deform into an oval under load and blister or delaminate when exposed to hot water or fats, and that enthusiastic jetting can make them worse (Drainiacs). Where the pipe can be re-rounded first, relining is often still possible. Where it can't, excavation is the answer. Our guide to the signs of a blocked or collapsed drain explains what to look out for.

How do relining and excavation compare?

The prices in this table are national market ranges from the guides below, not a quote.

What do relining and excavation cost in the UK?

Published price guides give these typical ranges. Real prices vary with region, access, depth and pipe size:

• Checkatrade's drain repair cost guide puts relining at £70–£130 per metre for 100 mm pipes and £120–£170 per metre for 150 mm pipes, with patch repairs at £200–£450.
• MyBuilder's drain relining guide gives £70–£250 per metre, £350–£1,200 for a patch repair, £600–£2,000 for up to 5 metres and £1,500–£4,000 for a full lateral.
• MyJobQuote's drain repair guide (August 2026) puts excavation and replacement at £250–£650 per metre, a typical collapsed-drain repair at about £850 and a fully collapsed drain at £1,000–£3,000. It adds £500–£2,000 when the pipe is under a drive or extension, £200–£500 for each extra metre of depth and £300–£1,500 for reinstatement.
• Checkatrade's collapsed drain guide gives £295–£775 per metre, with an average of £535.

When you compare quotes, check whether each one includes VAT, the clean before lining, a camera check afterwards and any reinstatement.

Do drain repairs need Building Regulations approval?

Usually not for like-for-like work. Drainage is a controlled service under the Building Regulations, but the government says most repairs that simply replace like with like don't need approval (gov.uk). New connections, re-routed runs and extensions to the system do. Either way, Approved Document H says repairs should meet the standard expected of new work (para B.15). If you're unsure, ask your local building control team before work starts.

Why a CCTV survey should come first

You can't choose between relining and excavation without seeing inside the pipe. A CCTV survey shows the type, size and position of each defect, the pipe material and diameter, and whether the pipe still holds its shape. Reports coded to the WRc Manual of Sewer Condition Classification (MSCC5) describe defects in a standard way, so another contractor or an insurer can read them. Our guide explains what a CCTV drain survey report shows.

Insurers use the same language. WRc says its Drain Repair Book (4th edition, 2017), produced with the ABI Property Claims Working Group, is widely used by both insurers and drain repairers (WRc). If you plan to claim, speak to your insurer before any repair; our guide on whether home insurance covers drain damage explains why.

Questions to ask before you agree a repair

• What defects did the survey find, and how far along the pipe are they?
• Why is this method right for this pipe, and what are the alternatives?
• Will the drain be cleaned before lining and checked on camera afterwards?
• What does the price include: VAT, reinstatement, waste disposal?
• Is the damage in a pipe I'm responsible for, or in a shared pipe that belongs to the water company? Citizens Advice explains the difference.
• What guarantee comes with the work, and what does it exclude?

When to call a professional

If a drain keeps blocking or smelling, or a survey has already shown cracks, root entry or displaced joints, get it inspected before the damage spreads. We carry out CCTV drain surveys from £120 + VAT with a written report, then recommend the least disruptive repair that will last: no-dig drain relining where the pipe is sound enough, or excavation and pipe replacement where it isn't.

There's no call-out fee, the price is agreed before we start, and lining, patching and pipe replacement all come with a 12-month guarantee. We cover Nottinghamshire, Derbyshire, Leicestershire and Lincolnshire, 7 days a week from 6am to 8pm. Contact us or call 07300 600 950.

Sources

• Approved Document H: drainage and waste disposal (gov.uk)
• When you don't need Building Regulations approval (gov.uk)
• Drain Repair Book, 4th edition (WRc)
• Who is responsible for repairing drains and sewers (Citizens Advice)
• Drain repair cost guide (Checkatrade)
• Collapsed drain repair cost (Checkatrade)
• Drain relining cost (MyBuilder)
• Cost to repair a drain line (MyJobQuote)
• Pitch fibre drains (Drainiacs)