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.

How does a CCTV drain survey work, step by step?

A CCTV drain survey works by sending a small waterproof camera along the inside of your drain and recording what it sees. On a typical house, it runs like this:

1. Find an access point. Usually the outside gully trap or an inspection opening. The closer it is to the suspected fault, the better.
2. Make sure the line is clear. The camera cannot see through standing water or a blockage, so the drain may need clearing or jetting first.
3. Push the camera along the pipe. The camera head sits on a flexible rod that is fed along the drain, with a live picture on a screen at the surface.
4. Record faults as they appear. Roots, cracks, open or displaced joints, sags where water sits, fat build-up and collapsed sections are all noted along with the distance from the access point.
5. Locate it from above. A transmitter in the camera head lets the operator find the exact spot and depth from the surface, so a repair can be planned without guessing where to dig.
6. Show you the result. You watch the footage and get to keep it.

How long does a CCTV drain survey take?

For most houses, the camera work itself is done in a single visit. What makes it take longer is not the camera but the drain: a blocked line has to be cleared first, a long lateral with several junctions takes more time to work through, and hard-to-reach access points slow everything down. If you need a written report as well as the footage, for a property purchase or an insurer, allow extra time for it to be prepared after the visit.

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 much does a CCTV drain inspection typically cost in New Zealand?

A standard residential CCTV drain inspection typically costs a few hundred dollars in New Zealand, and more when it includes a written report, several lines or a pre-purchase survey. The price moves with the length of drain, the number of access points, whether the line has to be cleared before the camera can travel, and whether you need faults located and depth-marked from the surface. Our blocked drain cost guide lists the ranges Auckland businesses publish.

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