Drain relining or replacement: what should the survey establish?

A patch targets a short damaged section. Relining treats a longer section inside the existing pipe. Excavation gives access to remove or replace pipework. OneFlow’s service guidance distinguishes local defects, multiple defects and collapsed pipes that cannot be lined.

Those descriptions help you ask questions; they do not diagnose your drain. Ask which option the inspection supports and whether the contractor has ruled out the alternatives for a specific reason.

Sources: OneFlow.

Request the relevant footage, still images and a plan or clear location reference. Match the quoted repair to the section shown in the report. If the camera stopped at a blockage, ask what is known about the pipe beyond it.

Write down the distinction between an observed defect and an assumption. “The camera could not pass this point” is a finding about access; ask what further evidence is needed before treating everything beyond it as collapsed.

Sources: DASA; OneFlow.

Ask each contractor to state the length and diameter covered, the preparation required and how the work will be checked afterwards. For excavation, ask who will restore the surface and what finish is included.

A cheaper quote may exclude clearance, a return inspection or reinstatement. An expensive quote may cover a different length. Put those differences beside the totals instead of declaring a winner from the headline price.

Sources: OneFlow.

Request the total including VAT and mark each item as included, excluded or not yet priced. A per-metre figure alone does not tell you the final bill when the length and preparation are uncertain.

For a hypothetical example, £800 plus 20% VAT is £960. If reinstatement is still unpriced, the project total remains unknown; £960 is only the known amount. These figures demonstrate quote arithmetic, not an estimate for your drain.

Sources: OneFlow.

Ask what report or footage will show the completed repair, and request written guarantee terms rather than relying on a headline duration. Clarify exclusions, maintenance requirements and who handles a later problem.

Before authorising private work, establish whether the affected pipe belongs to you or the sewerage company. CCW recommends contacting the provider where responsibility is unclear. If an insurer is involved, ask it what approval it needs before non-urgent work proceeds.

Sources: CCW.

• Which defect and pipe section does this quote address?
• Why is a patch, full lining or excavation appropriate here?
• What cleaning and access work is included?
• Who restores the garden, paving or driveway?
• Which amounts remain provisional or unknown?
• What is the total including VAT?
• What completion evidence and written guarantee will I receive?

Find and check a drainage contractor when you are ready to ask for quotes.