CCTV drain surveys for relining must do more than produce clear pictures. The recording needs to locate the defect from a known access point and show the route that cleaning and installation equipment would have to follow. It must also state which parts of the pipe could not be seen.
The recording should also admit what it could not see. Grease, standing water, roots or a smeared lens can hide the wall, and a repair should not be chosen from an image that stops at the obstruction. CCTV drain surveys for relining must make those locations and limitations clear.
Begin from an access point that can be found again
The chamber reference and direction of travel give the footage a fixed start. A continuous distance counter then links each crack, joint, branch and change of diameter to a real position underground.
If a blockage stops the camera before the full route is visible, clear it and continue the survey. The unseen section may contain another defect or a connection that changes the proposed repair.
Show the complete route to the fault
The camera view should cover bends, lateral connections and the narrowest section between access and damage. A small camera may pass through a turn that later stops a packer or folded liner, so the survey supports rather than replaces an installation check.
- Keep the pipe material, shape and changes in bore tied to a measured position.
- Show branches a liner could cover and any section hidden by water or deposits.
- Continue beyond the first defect far enough to see whether the damage carries on.
Cleaning may be needed before the wall can be judged
Silt, scale and grease can make a sound surface look damaged or hide a crack completely. Roots can obscure the opening beneath them. Where the view is incomplete, cleaning before relining and a second pass provide a better basis for the decision.
Cleaning is not a reason to assume lining follows. It may expose a collapse, severe offset or missing support that points towards excavation.
A blind section stays unresolved
If water or geometry prevents the camera reaching part of the route, that limitation should remain clear. A repair boundary cannot safely be inferred across pipe that has not been seen.
Use the chamber, camera direction and measured distance again in the repair proposal. Customers can then compare different scopes against the same damaged section without relying on method labels.
Our guide to what CCTV should show before relining explains how to read those positions without turning the survey into a list of unexplained codes.
Compare the visible result afterwards
When relining proceeds, completion CCTV can return to the treated section and show the visible liner, ends and relevant connections. The original and final recordings are most useful when both use the same route reference.
CCTV cannot prove what lies behind the pipe wall or decide how a building can manage drainage restrictions. Those remain separate technical and site decisions.
Can a survey alone confirm that relining is possible?
No. It shows visible pipe condition and layout. The repair company must also check equipment access, preparation and how the drain can be taken out of use.
What if part of the pipe cannot be seen?
The limitation should stay explicit. Cleaning, another access point or a different investigation may be needed before choosing a repair.