A drainage investigation looks for the cause of a drain problem. It suits repeat blockages, damp patches, smells and wet ground. The aim is to find the fault, not just clear the pipe. Because a clear-out treats only the symptom, the problem can return.
Engineers use a camera to see inside the pipe. They may add a dye test or a locator to trace the route. Because each tool shows something different, the mix depends on the problem. Ask which tools the engineer plans to use.
The result is a plan for the next step. That could be a repair, a clear-out or no work at all. Ask for the findings in writing, since you may need them for a landlord, insurer or neighbour. However, the report is only as good as the access the camera had.
Price depends on how many drain runs the engineer must check. Tracing a route with a locator or dye can add time. Since the scope varies, ask what the quote covers. Ask what you will get at the end too.
Choose an investigation if the problem returns or the cause is unclear. A clear-out treats the blockage, while an investigation looks for the reason. It can help you avoid repeat visits. Still, a simple one-off blockage may need only a clear-out.
A camera can show cracks and joint faults that may leak. A dye test can help show where water escapes. However, some leaks need other checks. Ask the engineer what is possible for your drain.
Not for the survey itself, because the camera enters through access points. Digging comes later, and only if a repair needs it. The engineer should explain the options before any digging starts. You can still ask for a second quote, since repairs vary.
This page sits under cctv drain surveys, which covers the wider picture. For local details, see the pages for cctv drain surveys in Plymouth and cctv drain surveys in Tavistock, since each town has its own page. You can also read Why Home Buyers Should Consider a CCTV Drain Survey for a wider guide.