What causes blocked drains in older Cape Town homes (and how to prevent them)

If you live in one of Cape Town's older suburbs — anywhere with mature gardens and houses built before the 1970s — your drains face a different set of problems to a new build. Here is what actually blocks them, and what you can do about it.

Tree roots: the number one culprit

Older suburbs mean established trees, and established trees mean roots hunting for water. The sewer line is the best water source in the garden.

Most older Cape Town homes still have their original earthenware (clay) sewer pipes, laid in short sections with joints every metre or so. Over the decades those joints shift and open slightly, and that is all a root needs. It grows in through the gap, branches out inside the pipe, and forms a net that catches everything passing through. The first sign is usually a toilet that blocks every few months for no clear reason.

Cutting the roots out with a drain machine clears the line, but it is a haircut, not a cure: they grow back. The lasting fix starts with a CCTV inspection to see exactly where the roots enter - our camera's sonde locator marks the precise spot and depth from the surface - followed by a repair of that section, so you stop paying to clear the same blockage every season.

Grease, and what gets flushed

Fat poured down the kitchen sink sets like candle wax inside a cool underground pipe, narrowing it year by year until an ordinary load of washing-up water tips it over the edge.

Sanitary products and paper towels do not break down like toilet paper. In a smooth new pipe they might pass; in a rough, root-nicked, sixty-year-old line they snag and build a plug. Only toilet paper goes down the toilet - it is the cheapest plumbing advice you will ever get.

The warning signs worth acting on

Drains rarely block without notice. Slow draining, gurgling from plugholes when other fixtures are used, sewage smells in the yard, or water rising in a gully are all early warnings. The earlier you act, the cheaper the fix: a blockage cleared at the slow-drain stage is a quick visit, while the same blockage at the overflowing stage can mean a weekend of misery.

Plungers and supermarket drain cleaner have their place, but if a drain blocks repeatedly, if more than one fixture is affected, or if anything is backing up out of a gully, the problem is in the line and needs proper equipment. We clear blocked drains across Cape Town with drain machines, jetting and CCTV diagnosis - and we tell you honestly whether it is a once-off or a symptom of something that needs fixing.