Reline a damaged drain.

By inserting a resin-impregnated liner into the existing pipe, specialists create a "pipe within a pipe" that is often stronger than the original. This guide breaks down the costs, processes, and essential regulations you need to know for 2025/26.

What Does the Work Involve?

• CCTV Drain Survey: A high-definition camera is fed into the system to identify the exact location and nature of the damage.
• High-Pressure Water Jetting: The pipes are thoroughly cleaned to remove scale, grease, and debris, ensuring the resin bonds correctly.
• Liner Preparation: A felt or woven sleeve is saturated with epoxy or silicate resin tailored to the pipe's specific requirements.
• Insertion: The liner is pulled or "inverted" into the pipe using air or water pressure to ensure it fits tightly against the existing walls.
• Curing: The resin is left to harden, often accelerated using hot water, steam, or UV light for a faster turnaround.
• Re-opening Junctions: If the liner covers any connecting pipes, a robotic cutter is used to precisely reopen those lateral connections.
• Final Inspection: A second CCTV survey confirms the liner is smooth, sealed, and free of defects.

Typical Costs

Prices vary based on the diameter of the pipe, the length of the run, and the type of resin used. Most residential jobs are priced per "patch" or per linear metre.

Costs are primarily driven by access. If a manhole is buried or inaccessible, additional labour will be required to create an entry point. Complex bends also require more expensive, flexible liners.

How Long Does It Take?

• Small Patch Repair: 3–5 hours. This includes setup, cleaning, and curing time.
• Full Length Relining (Standard House): 1 working day. Most residential runs can be completed between morning and late afternoon.
• Complex or Multi-line Systems: 2–3 days. Required if there are multiple junctions to cut out or significant root mass to clear first.

DIY or Professional?

Professional only. Drain relining requires specialist calibrated equipment, including high-pressure jetters, inversion drums, and CCTV crawlers. Attempting a DIY fix with "off-the-shelf" resins often leads to "liner collapse," which is incredibly expensive to rectify as it usually requires full excavation.

Relining is a structural repair. If done incorrectly, it can block your entire drainage system, leading to sewage backup into your home.

Choosing the Right Tradesperson

• Qualifications: Look for NADC (National Association of Drainage Contractors) membership.
• Insurance: Ensure they hold Public Liability insurance of at least £2 million.
• Red Flags: Avoid anyone who quotes without seeing a CCTV survey first or who suggests "patching" a pipe that is clearly collapsed.
• Questions to Ask:
  • Is the resin you use suitable for hot water (kitchen) waste?
  • Will I receive a copy of the "before and after" CCTV footage?
  • Does the repair come with a 10-year or 50-year structural guarantee?

UK Regulations

• Building Regulations Part H: All drainage work must comply with Part H (Drainage and Waste Disposal). Relining is generally accepted as a repair, but it must not restrict the flow of the pipe.
• Water Authority Approval: If the damaged pipe is a "lateral drain" or "public sewer" (usually pipes shared with neighbours), it is the responsibility of your local water company (e.g., Thames Water, United Utilities). You should not repair these yourself.
• Environment Agency: Resin chemicals must be handled strictly to prevent contamination of local watercourses.

Common Problems

• Resin Shrinkage: If the wrong resin mix is used, the liner can pull away from the pipe walls, allowing water to leak behind it.
• Wrinkles and Folds: Poorly installed liners can create "lips" that catch toilet paper and debris, leading to frequent blockages.
• Incomplete Curing: If the liner doesn't harden fully, it may deform or collapse under the weight of the soil above.
• Blocked Laterals: Failing to accurately cut out junctions means your sinks or toilets from other parts of the house won't drain.

Frequently Asked Questions