A collapsed drain is often one of the harder problems to diagnose as the blockage is out of sight. With a drain camera survey it will be possible to establish what has caused the blockage and where the problem is located.
What a Partial Collapse Looks Like on Camera
In a partial collapse of a pipe, part of the pipe wall may have collapsed into the pipe creating a partial blockage. On the camera footage it will look like an obstruction in the pipe such as a piece of broken clay pipe or concrete. The obstruction will create areas of high water pressure upstream of the blockage and silt will potentially fill up the pipe before the collapse, exacerbating the blockage over time.
What a Full Collapse Shows
A full collapse appears on the CCTV footage as a solid wall of debris or soil which has collapsed into the pipe. From the end of the camera it will appear that the end of the pipe has come to a close at the point that the camera stopped running. This would typically be a distance from the manhole access that has been noted on the survey report.
Why Collapses Happen
Ground movement, heavy traffic above, tree root invasion and the age of the pipe are all known to cause collapses of drains. Older clay and pitch-fibre drains are particularly prone to damage of this nature. A CCTV Drain Survey Loughborough can identify root invasion of older properties with mature trees nearby.
How the Survey Guides Repair Decisions
The footage shows whether a complete excavation and replacement of the damaged pipe is required or if a structural liner can be inserted through the access point. This is all covered in the guidance for classifying collapse severity in buried pipe condition assessment (CIRIA C694).
Knowing exactly what the camera has found will enable you to make the repair decision quickly and cost effectively.
