A CCTV drain survey is the best diagnostic tool for any drain problem that rodding or jetting does not solve, because it shows the pipe itself. You may have a repeat blockage, or slow drainage that returns within weeks. You may be buying a home, or you may have a dispute with a neighbour over drain duties. In each case, a survey gives timestamped evidence of the exact state of your pipes, since the camera sees every metre. Here is what happens, from the engineer's arrival to the report you receive.
What Is a CCTV Drain Survey?
A CCTV drain survey sends a remote camera along your drain pipes and records the footage in high definition. The camera head rides on a motorised crawler, or it is pushed on a flexible rod. It sends live pictures to a monitor at the surface. Engineers can turn the camera to look at close detail. They can judge the pipe size and condition, and they can pinpoint any defect.
A quick look is different, because a survey gives a lasting video record. You can share it with your insurer, Thames Water or a solicitor. It is not a visual estimate. It is documented evidence.
Step 1: Setting Up at the Inspection Chamber
The engineer starts by finding the nearest inspection chamber, or manhole, since it gives the best way in. In most London homes, it sits in the back garden. For shared drains, it may lie in the pavement or a shared passage. The engineer opens the chamber, clears any standing water and prepares the camera.
Some homes have no accessible chamber, which is common in Victorian terraces, although there are ways round it. In that case, the camera may enter through an internal access point such as the soil stack. Or the engineer may make a temporary access point.
Step 2: Camera Insertion and Live Monitoring
The engineer feeds the camera into the pipe and watches the live feed on a monitor, while the system records every metre. The engineer describes what the camera shows, noting each defect, its distance from the access point and how severe it looks. Modern kit also measures distance, so it can map the exact position of each pipe section.
Step 3: What the Camera Looks For
A systematic survey checks for these faults:
- Root intrusions: roots entering through cracked joints or damaged pipe walls
- Displaced or open joints: sections that have moved out of line through ground movement
- Cracks and fractures: these are common in clay pipes after decades of shrink-swell in London Clay
- Collapsed sections: places where the pipe wall has caved in, which often need a dig
- Grease and fat deposits: a yellowish coating on the pipe walls that narrows the bore
- Silt build-up: common at the foot of slopes and in slow-flow sections
- Wrong connections: surface water pipes joined to foul drains by mistake
- Pipe deformation: an oval shape in flexible plastic pipes under heavy load
Step 4: Recording Footage and Noting Defect Positions
The system records all footage with times and distances, because exact spots matter for repairs. When the engineer spots a defect, they note its position. A typical note might say "displaced joint at a set distance from the chamber, at a known depth". This lets a later repair aim at the fault with no trial digging.
A pre-purchase survey gives a written report that grades each defect by how bad it is, while a diagnostic survey focuses on the cause. For diagnostic surveys, the report focuses on the cause of the problem. It also recommends the fix.
What the Survey Can Find
These are the most common findings on London drain surveys, particularly in homes built before 1960:
- Roots from street trees, where plane trees and limes are frequent offenders
- Displaced joints in clay pipe runs, caused by decades of London Clay movement
- Cracked pipe sections, often at bends and junctions
- Fat and grease in kitchen drain runs, particularly under older homes with little slope
When Do You Need a CCTV Drain Survey?
A survey is worth it in six situations:
- A blockage returns within weeks of being cleared.
- Several drains in the home back up together, which suggests a fault in the shared drain instead of a single blockage.
- You are buying a London home built before 1960.
- You plan building work near existing drains.
- You have a dispute with a neighbour about drain responsibility.
- There has been ground movement, tree removal or major digging near your property.
What You Will Receive
After the survey, you receive these items:
- Full video footage of the camera run, with timestamps
- A written condition report that notes each defect with its position and severity grade
- Recommended next steps, such as jetting, pipe relining or digging and replacement
- A site plan of the drain route and defect locations, for more detailed surveys
For full pricing across survey types, see our CCTV drain survey cost guide. Our surveys cover Greater London, and our London drainage service area shows the full coverage. For urgent surveys and diagnosis, request a quote online via our contact form.
Frequently Asked Questions
How long does a CCTV drain survey take?
Most home surveys take a short visit on site, although the length varies. Long pipe runs or several branches take longer. We provide the written report after the visit.
Do I need to be present during the survey?
You do not need to be there throughout. However, it helps to be available at the start, so the engineer can discuss access and any symptoms you have seen. Watching the live footage with the engineer helps you understand what they find.
Will the camera damage my pipes?
Drain cameras are made for drain pipes, because they must pass through tight bends, so they do not damage sound pipework. In badly decayed pipes, the camera may knock loose a little material. It cannot cause structural damage, though.
Can a CCTV survey see under my house?
Yes, because the camera can travel the whole length of any drain it can enter, even under the building. The survey records depth and position throughout.
Is a CCTV survey the same as a drain inspection?
Not quite, since a basic inspection is a visual check of what you can easily reach, such as the chamber, the gullies and obvious blockages. A CCTV survey films the whole underground pipe run and produces a video record. For pre-purchase surveys and repeat problems, you need a full CCTV survey.
Because every property is different, start with our guides to cctv drain surveys and kitchen drain blockages advice. We also cover cctv drain surveys in Croydon and cctv drain surveys in Ealing, so you can see how the work runs near you.
