Topic videos Short technical primers from Catalyst

Household drainage systems: how they're built, how faults develop, and how they're diagnosed.

Identifying pipe location, structure and defects using the standard CCTV coding system.

Common causes of pipe defects — cracking, collapses, wear mechanisms — and how each presents on CCTV.

Types of joint displacement in sewer systems — how pipe sections separate and what triggers it.

Different crack types, formation causes, and why repair-method selection matters per crack pattern.

Installation and function of backdrop / drop-shaft manholes in drainage systems.

Why planned and preventative gully maintenance matters — preventing blockages and the subsidence risk that follows.

Water sourcing, routing, and how to identify ownership of buried gully connections.

Using radio-wave detection (CAT scanner) and a Sonde to pinpoint underground pipe locations.

Three forms of root ingress: fine roots, tap roots and root mass — recognition and remediation.

Water-drop tests to verify proper drainage and detect leaks — used on every subsidence investigation.