Should I get one before buying?

It is worth it where there are mature trees near the runs, where the property has been extended over drainage, where there is a known history of blockage, or where the property is older and the runs are original clay.

My report is full of codes I do not understand. What now?

Ask for the severity grades and the distances in plain terms, and get an independent reading before authorising work. Coded reports are written for the industry, not for the owner paying the invoice.

Can a drain defect cause subsidence?

A long-term leak can wash fine material out of the ground supporting a foundation, and that is one recognised mechanism among several. Establishing it in a specific case needs a structural assessment, not a camera alone.

CCTV drain survey (remote camera drainage inspection)

CCTV drain survey

Camera inspection of below-ground drainage: how defects are coded, what the footage proves, and what it does not settle about cost or liability.

Ask KJ about a drain survey 01706 318200

Last reviewed 31 August 2026

What is a CCTV drain survey?

A CCTV drain survey pushes or crawls a camera through below-ground pipework and records what it finds. It establishes the layout and connectivity of the runs, and identifies cracks, displaced joints, root ingress, scale, standing water and collapses. Findings are recorded against a standard coding system and referenced to distance along the run, so a repair can be located precisely rather than excavated speculatively.

At a glance

Method: Camera introduced at a chamber and driven along the run, recorded to video.
Output: Coded defect list, distances, a layout plan and a recommendation.
Commonly required for: Purchases, insurance claims, pre-extension checks and recurring blockages.
Carried out by: A drainage specialist. We interpret the findings in the building context.

What the coding actually tells you

Camera survey reports use a standard defect coding convention rather than plain description. That is useful in principle, because it makes reports comparable, and confusing in practice, because a homeowner receives a page of abbreviations and a repair quotation attached to it.

The important reading is severity and location. A fine circumferential crack in a clay pipe at a shallow depth is very different to a displaced joint with active root ingress under a conservatory. Both may appear as defects on the same list.

Defect type, severity grade and distance along the run
Root ingress and whether it is currently obstructing flow
Standing water, indicating a sag, a partial blockage or a fall problem
Connectivity: what drains where, and which runs are shared

What the footage does not settle

A camera shows the inside of a pipe. It does not establish who owns the run, whether an insurer will accept the claim, whether the defect caused the building movement above it or what the repair should cost.

It also cannot see everything. Runs full of water, heavily blocked sections and pipework with no available access point may go unrecorded, and the report should state where the camera could not reach.

The point at which it becomes a building question

Where a defective drain sits close to foundations, long-term leakage can wash out fine material from the supporting ground. If the property is also showing cracking that fits that pattern, the drainage report becomes one input into a movement assessment rather than the whole answer.

This is the situation in which an independent surveyor is worth having alongside the drainage contractor: one party is describing the pipe, the other is deciding what it means for the building.

Common camera findings and what usually follows

Illustrative only. Severity and location decide the response in any specific case.

Finding	Usual significance	Typical next step
Fine cracking, no displacement	Often monitored rather than repaired	Record and review
Displaced joint with root ingress	Recurring blockage and ongoing leakage	Cut and reline, or local excavation
Standing water along a section	Sag, poor fall or partial obstruction	Jetting, then re-survey
Collapsed section	Failure requiring physical repair	Excavation or full reline
Defect adjacent to foundations	Possible ground-loss contribution to movement	Structural assessment alongside repair

Who this is for

A good fit if

Buyers of properties with mature trees, extensions or a history of drainage trouble
Owners with a blockage that returns however often it is cleared
Anyone supporting an insurance claim that requires evidence of a drainage defect
Owners planning to build over or near an existing run

Not the right choice if

Establishing legal ownership of a drainage run
Diagnosing structural movement on its own
Situations where a straightforward blockage simply needs clearing today

Getting value from a camera survey

The footage is only as useful as the questions put to it.

1.Decide what the survey needs to prove
Purchase due diligence, an insurance claim and a recurring blockage need different emphasis in the report.
2.Make sure the runs are accessible and cleared first
A camera in a blocked pipe records the blockage and little else.
3.Read the coding with someone independent of the repair quote
Severity grading drives cost, and the party grading it is often the party pricing it.
Drainage surveys
4.Escalate where the building above is affected
Cracking, sinking paths or a settling extension turn this into a structural question.
Crack and movement surveys

When to bring in a specialist

Camera survey, jetting, relining and excavation: a drainage specialist contractor.
Ownership and adoption of a run: your sewerage company and your solicitor.
Structural calculations, load paths and remedial design: a structural engineer. A surveyor describes and diagnoses; it does not design.

Common questions

Limitations and sources

A camera survey records only the runs it can enter. Inaccessible, surcharged or heavily blocked sections may be unrecorded.
Footage describes pipe condition; it does not determine liability, insurance outcome or repair cost.
KJ Surveyors interprets drainage findings in a building context; the camera survey itself is carried out by a drainage specialist.
Nothing on this page is a professional opinion about a specific property. KJ Surveyors has not inspected your building, and general guidance cannot replace an inspection and report.

Source: Ofwat · checked August 2026

Source: UK Government · checked August 2026

Source: RICS · checked August 2026

Last reviewed 31 August 2026.

Where to go next

a wider drainage survey — when layout, ownership and above-ground pipework also matter.
movement assessment — where a drainage defect may be affecting the building.
defect surveys — for a focused report on one identified problem.

Blockage that keeps coming back?

Tell KJ where the property is, how old the drainage is and what keeps happening. KJ will explain whether a camera survey will settle it.

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KJ gives general guidance only and has not inspected your property. A professional opinion follows an inspection by a surveyor.