CCTV drain surveys — what they are and how to read one
Understand the video, the report, and the terminology so you can make good repair decisions.
How a CCTV survey works
A self-levelling HD camera on a motorised or push-rod crawler is inserted at a manhole or rodding eye and pushed through the drain run. The camera transmits video back to the operator, who records footage and logs every defect against the WRc (Water Research Centre) grading system.
What the WRc grading means
Grades 1–5. Grade 1 defects are cosmetic; Grade 5 defects are structural failures requiring immediate action. Most Victorian clay drainage in older properties will show a mix — Grade 2 open joints, Grade 3 root ingress, occasional Grade 4 or 5 collapses.
Common defects and what they mean
Open joint: the joint between two pipe sections has opened up, allowing water out and roots in. Patch lining fixes it.
Root ingress: fine or heavy roots entering through joints. Cut and line.
Displaced joint: pipes no longer aligned. Small displacement — line. Large — excavate.
Cracked pipe: patch lining unless multiple.
Collapse: excavation almost always required.
Using the report
Take the report to at least two drainage contractors before agreeing repair work — quotes vary widely. A good contractor will always try lining before excavation. Keep the report — it's valuable evidence for future homebuyers or insurance claims.