CCTV Drain Surveys Explained: How They Work and When You Need One

A CCTV drain survey is an inspection of the inside of a drain or sewer using a waterproof camera, usually fed in through an inspection chamber. It records the condition of the pipe and pinpoints faults such as cracks, root intrusion, displaced joints and blockages, without any digging. You get video footage and a written report you can use to plan repairs, buy a property or support an insurance claim.

How a CCTV drain survey is carried out

1. We find and lift the inspection chambers (manholes) to get access to the drain run. Where there is no chamber, access can sometimes be made through a gully or a rodding point.
2. If the drain is blocked or heavily fouled, we clear it first, usually with high-pressure water jetting. A camera can’t see through standing water or debris.
3. The camera goes into the pipe. For most domestic drains it is mounted on a flexible push-rod fed from a reel. For larger pipes and sewers, a camera on a remote-controlled crawler can travel further.
4. The engineer watches a live picture on a monitor while the camera moves along the pipe. The distance travelled is recorded on screen, so every observation has a position.
5. Where needed, a locating sonde in the camera head lets us trace the line and depth of the pipe from the surface and mark it on the ground.
6. The footage is reviewed and written up into a report.

What the report contains

A useful report should let someone who wasn’t there understand the condition of the drains. It normally includes:

• The video footage of each run inspected.
• A list of observations along each run, with the distance from the starting chamber, such as cracks, fractures, open or displaced joints, roots, deformation, scale, grease or debris.
• Still images of the main defects.
• A plan or sketch showing the chambers, the direction of flow and the position of each defect.
• Pipe material and diameter where they can be identified.
• Recommendations, for example cleaning, patch lining, full relining or excavation, with the reasons.

Many surveyors code their observations to a recognised UK standard, the WRc Manual of Sewer Condition Classification, which makes reports consistent and easier for insurers and other contractors to read.

When it’s worth getting one

Buying an older property

Much of Central London’s housing stock is Victorian or Edwardian, often with original clay or cast-iron drains. A standard building survey doesn’t look inside the pipes. A pre-purchase CCTV survey can reveal cracked, root-filled or collapsed sections before you commit, and gives you something concrete to negotiate with.

Recurring blockages

If a drain blocks again and again, something is usually catching the waste: a displaced joint, a dip in the pipe, roots or a damaged section. A survey finds the cause so it can be fixed once, rather than cleared every few weeks.

Subsidence or damp worries

A leaking drain can wash out the ground under a wall or floor. If you have new cracking, a sinking path or patio, or unexplained damp low on a wall, it is sensible to rule the drains in or out.

Before building over or near a drain

Extensions, basements and new patios often sit over or close to drains. A survey confirms where the pipes run and what condition they are in before work starts. If a public sewer is involved, you will usually need the water company’s consent (Thames Water in London) before building over or close to it.

Insurance claims

Insurers usually want evidence of what has gone wrong and where. A clear report with footage and positions helps show the damage and supports the repair you’re proposing.

What happens after the survey

If the drains are in good order, you have a record that shows it. If there are defects, the report shows exactly where they are, which keeps repairs targeted. Many faults can be fixed with no-dig relining, which forms a new pipe inside the old one through the existing chambers. Where a pipe has collapsed or relining isn’t suitable, an excavation repair may be needed, and the survey tells us exactly where to dig.

Our CCTV drain survey team covers homes and businesses across Central London. We provide a free quotation before any work, and we’re available 24 hours a day, 7 days a week. Call 020 3670 7648 to book a survey or talk through what you’re seeing.