How Blocked Drains Happen

Common Causes of Blocked Drains

The most common cause of blockages in underground sewer and stormwater pipes is tree roots, which enters the pipe via the joints or cracks in the pipe joints or through breaks in the pipe wall (see 'Example of blocked pipe' picture).

• Drains may block regularly due to insufficient gradient in the pipework, which causes the water to run slowly, leading to debris build-up and blockages.


• Too many bends and certain types of junctions can cause the same issues as with insufficient gradient


• Pipes may become misaligned or completely collapse (see 'Drain camera vision' picture) due to incorrect installation or from external forces such as pressure from large tree roots or ground movement due to drought or heavy rain.


• Blocked Drains may also be due to larger objects being flushed which the drain is not designed to cope with, such as toilet deodorant block holders, sanitary products and baby wipes.

For assistance with

• Blocked drains or
• Plumbing emergencies

Contact O’Shea Plumbing & Blocked Drain specialists

Phone: 03 9888 2887