By Tom Baxter, Managing Director, Rausch UK
The defects that cause the most expensive problems on UK drainage networks are rarely the ones that look dramatic on a screen. They are the ones that look fine, or look minor, or look like something the operator has seen a hundred times before. They get noted, sometimes. Quite often they get glossed over. Then, six months or a year later, someone is back on site or digging up a road that should have stayed undisturbed.
These are the ones I hear about most often when I talk to contractors and survey teams. Different jobs, different ground, different equipment, and the same list comes back.
Rocking joints
A joint that moves under load is one of the most commonly overlooked defects in CCTV surveys. On the monitor, it can look like nothing at all. The camera passes through, the pipe is round, the joint is visible, nothing is obviously leaking. But the joint moves every time something heavy drives over it, and each cycle brings it closer to failure.
A typical case is an access road or service yard where heavy vehicles pass over the same spot day in, day out. The first survey shows slight joint movement, no obvious leak, no collapse, so it gets logged as low priority. Six months on, the same section is being investigated after repeat blockages or visible settlement at ground level. What could have been planned maintenance has become a monster excavation project.
Hairline cracks
There is a school of thought that hairline cracks are not worth reporting. On the wrong pipe in the wrong ground, they are exactly what is worth reporting.
They are far too easy to dismiss on screen because the pipe still looks largely intact. But on older clay or concrete under trafficked ground, a hairline crack is often the first visible sign that the pipe wall is weakening. Left unattended, the next survey shows deformation, water ingress, or root entry in the same place. A small repair decision becomes a much bigger reinstatement. The old DIY adage of measure twice, cut once, translates in our world to buy cheap, buy twice, or survey cheap, survey twice.
Root intrusion written off as minor
Roots are interesting because everyone knows they are a problem. We find, though, that the big question is when they stop being cosmetic and start being structural. The honest answer is sooner than most reports suggest. A fine root mat across the invert is rarely just sitting there. It is in the joint, in the wall, doing slow, powerful work.
A typical case is an older run close to trees, hedges or landscaped ground. The first survey shows light root intrusion and it gets treated as a clearance issue. Cut it, jet it, move on. Six months later the blockage is back, the roots are heavier, and the real problem becomes far clearer. The roots were never the defect. They were the evidence of an open joint, a crack or a weakness that should have been flagged properly the first time around.
Infiltration missed because the camera was moving too fast
This one is operator-driven rather than equipment-driven, and it is the one that bothers me the most. A trained operator running a system at a sensible pace will pick up infiltration that a rushed operator will miss almost every time. The kit is not the limiting factor; the operator and the time they are allocated to do the job are.
The difference is usually visible in the footage. A good operator slows down at joints, laterals, bends, changes in material, staining, deposits, and anywhere the image looks slightly different. Good operators are pros; they see things the rest of us can’t, and their eyes are fine-tuned over years of experience. They pause, pan or reverse if needed. Infiltration is not always a dramatic flow of water. Sometimes it is staining, a wet joint, a slight trickle, or fine material being drawn into the pipe.
Why it happens
There is no single reason, but the common ones are pace, training and reporting standards.
- Pace, because survey work is priced by the metre and there is always pressure to move
- Training, because the gap between an operator who knows what to look for and one who is following a checklist is enormous, and rarely visible to the client buying the report
- Reporting standards, because a defect coded one way looks different in a contractor's planning meeting than the same defect coded a level up or down.
The good operators do the same things consistently - they do not just record a pipe end to end; they read the pipe as they go. They slow down when something changes, capture enough evidence for whoever reads the report later, and understand that the value of a survey is not in completing the metreage - it is in giving the customer a reliable basis for the next decision.
The standard worth working to
The kit has to work where the job happens. So does the operator, and so does the report. A survey is only as good as the defects it catches and the way it communicates them. The cost of missing the small ones is paid later, by someone, almost always at multiples of what it would have cost to log them properly the first time. Time is money, and nobody wants to go back to the same site twice.
That is the standard worth working to. The good teams we work with already do. Every survey season throws up reminders that it is not yet universal.
This article appeared in Issue 339 of Drain Trader magazine, July 2026. You can view it here.