What a CCTV Drain Inspection Actually Shows, and When You Need One
"Get a camera down there" is advice people hear a lot without ever being told what the camera is looking for. Here is what a survey actually finds, and when it earns its cost.
What the camera is looking for
A drain camera is a small waterproof head on a flexible rod, pushed along the inside of the pipe with the picture coming back live. A counter on the reel records how many metres in the head is at any moment, so anything found has a distance attached to it. That distance is the whole point: it turns "there's a problem somewhere in the drain" into "there's a problem 8.4 metres from the gully, under the paving".
The defects it typically turns up:
Root intrusion. Fine roots find the joints in older clay and cast-iron pipe, then thicken. On camera they look like a curtain or a beard hanging into the flow. They catch everything that passes, which is why root-affected lines block again and again in the same spot.
Cracks and fractures. From hairline to a section that has broken open. Ground movement, tree pressure and age all do this.
Collapse. A section that has lost its shape entirely. Usually the end of the line for that piece of pipe.
Bellies and back-falls. A dip or a reversed slope where water stops running and solids settle. Nothing is broken, but the pipe will never stop blocking there. Often caused by ground settling under a section that was not properly bedded.
Scale and grease build-up. The pipe narrowing from the inside. Common in old galvanised waste lines and in kitchen branches with years of fat behind them.
Displaced joints and offsets. Where two lengths of pipe have moved out of line, leaving a lip that catches debris.
Foreign objects. Builders' rubble, dropped tools, and, often enough, a stray cloth or nappy.
What the process involves
Access is through an existing point: an inspection chamber, a gully, or a removed toilet pan if there is no other way in. The line is usually flushed first, because a camera cannot see through standing sludge.
The survey itself takes anywhere from twenty minutes for a single run to a couple of hours for a full property with several branches. You get a recording and, from a decent operator, a written summary saying what was found, at what depth and distance, and what it means.
Ask for that recording. It is your evidence, whether for the City, an insurer, a seller, or simply for comparing against a second opinion.
The four times it is worth doing
The same drain has blocked repeatedly. Two or three times in a year in the same place is a structural problem, not bad luck. Each unblocking is renting a solution.
Before you buy a house. Drains are not part of a standard South African home inspection, and a failed lateral on an older property is a serious bill that becomes yours on transfer. On a home built before about 1970, this is cheap insurance.
Before you pave, build or landscape. Finding a cracked line after the new driveway has been laid over it is an expensive kind of surprise.
When someone has quoted you for excavation. A trench across a garden or driveway is a significant job. Before you agree, it is reasonable to ask to see the defect that justifies it, and to ask whether it can be lined instead.
What happens after
Not every finding needs work. Plenty of surveys end with "the pipe is fine, you had a one-off blockage", and that is a useful answer too.
Where there is a defect, the choice is usually between excavating and replacing the section, or relining it from the inside. Relining installs a resin liner through the existing pipe and cures it in place, forming a new pipe within the old one, sealing joints, bridging cracks and locking roots out, without opening a trench. It is not right for a fully collapsed section, but for cracks, root ingress and displaced joints it usually is.
Either way, the survey is what tells you which conversation you are having.
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