CCTV drain surveys explained: what you actually get for the money

What actually happens

It is less dramatic than it sounds. The camera goes in through an existing access point — usually the outside gully trap or an inspection chamber. For domestic laterals it is a camera head on a flexible push rod; for larger diameters, a motorised crawler unit that drives itself along.

As the camera travels, distance is measured continuously, so every observation has a position: root intrusion at 8.4 metres, not roots somewhere in the line. That precision is the whole point.

When something needs pinpointing, a sonde in the camera head transmits a signal that a locator picks up from above ground. The operator walks the surface, finds the peak signal, and marks the spot — along with the depth. That is what makes a targeted repair possible instead of exploratory digging, and it is the difference between a two-metre excavation and a trench across your lawn.

What it can and cannot see

What it finds

• Root intrusion — and the joint or crack it entered through, which is the more important finding.
• Cracks and fractures, including the brittle failures typical of ageing earthenware.
• Displaced or open joints where sections have moved apart through ground movement.
• Dips and back-falls — sections that have dropped and now hold standing water, permanently collecting solids.
• Partial or full collapse, which immediately rules out clearing as a solution.
• Fat, scale and silt build-up, and whether the wall underneath is sound.
• Incorrect connections, most commonly stormwater plumbed into the wastewater line.
• Route and depth of the line, which matters enormously before anyone excavates.

What it cannot do

• See past a solid blockage. Though where the camera stops is itself useful information.
• See through the pipe wall. It shows the inside surface, not voids or washed-out bedding outside.
• Always negotiate sharp bends or certain junction configurations.
• Tell you what a repair will cost by itself. It gives the evidence a quote is built from.
• See clearly through standing water. A sagging section holding water can obscure the invert.

When it is worth the money

Not always — and anyone selling you one for a first-time blockage with no history is overselling.

Worth it:

• The drain has blocked more than once. This is the clearest case: the survey usually costs less than the next clear and it actually answers the question.
• Before anyone quotes a repair. A repair quote with no footage behind it is an estimate in a suit.
• Buying a property, particularly an older one with mature trees — see pre-purchase drain inspections.
• Deciding between relining and excavation.
• A dispute over a shared drain, where footage showing exactly where the fault sits settles it.
• After significant work, to verify the repair.

Probably not worth it: a single blockage at a property with no history, cleared easily, with an obvious cause — a child's toy, a first-ever fat blockage. Clear it and see whether it recurs.

How to read the footage

You do not need to be an expert, but a few things help you follow along and ask better questions.

• Watch the distance counter. Every fault should be tied to a metre reading. If the operator cannot tell you how far along something is, that is a problem.
• Fine roots look like hair or a curtain hanging from the top of the pipe at a joint. Established intrusion looks like a bird's nest filling the bore.
• A joint should be a clean ring. A step, a gap, or daylight through it means displacement.
• Standing water in a level pipe means a dip. If the camera travels through a pool and comes out the other side, that section has dropped.
• Ask what the pipe is made of. Earthenware, concrete, asbestos-cement and uPVC look distinct on camera and each fails differently. It changes the repair options.
• Ask what the rest of the line looks like. One bad joint on an otherwise sound run is a patch. Bad joints throughout is a different conversation.

Above all, ask the question that matters: does this actually need fixing, and if so, when? Not every defect found on camera is urgent. A minor root at one joint on a drain that has never blocked is worth monitoring, not excavating. A good operator will tell you that unprompted.

What you should receive

• The video footage. Yours to keep, not just to watch on the day. This is non-negotiable — be wary of anyone reluctant to hand it over.
• Still images of significant findings.
• Distances for each fault.
• Surface location and depth where a fault has been sonde-located.
• A plain-language explanation of what it means and what the realistic options are.
• A written condition report, where you need one for an insurer, solicitor, body corporate or property manager.

If you are a landlord justifying a repair to an owner, a buyer deciding whether to proceed, or someone getting a second opinion, the footage is the evidence. It is the most valuable thing you take away from the visit.

Frequently asked