Local drains
Mid-1970s houses, mid-1970s pipes
The name Duncraig was approved in 1969 and the bulk of the suburb was built in the mid-1970s. That makes the typical house drain here around fifty years old. Water Corporation says suburbs over 20 years old are less likely to have PVC wastewater pipes, and those older pipes are the ones roots get into.
In old earthenware clay lines the weak points are faulty joints and cracks. A root finds the gap, grows into a mat and catches whatever comes down from the toilet and the kitchen. If your drain blocks again a few months after someone rodded it, that root mat is often what the camera shows.

