Blocked Drain or Something Worse? How to Tell the Difference | Pro Plumber Sandton Blog
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Blocked Drain or Something Worse? How to Tell the Difference

Short answer: A single slow drain is usually a local blockage. If multiple drains are slow at the same time, or you notice gurgling, bad smells, or damp patches in the garden, that points to a sewer line problem that needs proper investigation, not just a plunger.

Signs it’s a simple, local blockage

  • Only one drain is affected, for example just the kitchen sink or just one bathroom
  • It’s slow rather than completely blocked
  • It’s a fixture you know has a history, a shower that always struggles with hair, for example
  • There’s no smell, gurgling, or water backing up anywhere else

Signs it’s something bigger

  • Multiple drains are slow or blocked at the same time, especially ones on different parts of the property
  • You hear gurgling from drains when you flush a toilet or run a different tap
  • There’s a persistent sewage smell, inside or in the garden
  • A patch of garden is unusually wet, green, or soft with no obvious reason
  • Water backs up out of a drain rather than just draining slowly

Why the difference matters

A single blocked sink is a straightforward callout, usually cleared within the hour with rodding or a short jetting session. A sewer line problem, root intrusion, a collapsed section, or a break underground, is a different scale of job. Treating it like a simple blockage wastes time and money on repeat callouts that don’t fix the actual cause.

What causes sewer line problems

In older Sandton suburbs with mature trees, root intrusion into ageing clay or concrete sewer pipes is common, roots find their way into tiny cracks or joints looking for moisture and gradually block or break the pipe. Ground movement, old pipe materials reaching the end of their life, and previous poor repairs are the other common culprits.

How we figure out which one you have

If a standard unblocking doesn’t resolve the issue, or if the same drain blocks again within a short period, running a camera through the line tells us exactly what’s happening, whether that’s roots, a collapsed section, or something else, before we recommend a fix. It’s a lot cheaper than digging up a garden based on a guess.

Source: Johannesburg Water — Johannesburg Water’s sewer network is what your property’s drain line ultimately connects to.

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