Blocked Drains And What The Blockage Tells You

A blocked drain gets treated as a one hour job. Someone comes, clears it, everyone moves on.

Then it blocks again in four months, and again after that, and by the third visit the owner is paying more in call-outs than the repair would have cost.

What is in the blockage tells you which of those two situations you are in.

Roots

Fine roots in the material that comes out means a crack or an open joint somewhere in the line, and the tree has found it.

Clearing it works. It just resets the clock, because the crack is still there and the root will grow back into the same place. In older Eastern Suburbs streets with mature street trees, this is the most common cause we see in ground-level lines.

The fix is finding the entry point with a camera and repairing that section, either by digging it up or relining it from inside.

Grease and fat

Soft build-up on the pipe wall, usually in a kitchen line or a line serving several kitchens in a building. It narrows the pipe gradually until something small tips it over.

This one is behavioural as much as physical. Clearing it and doing nothing else means it returns on a predictable cycle. In a building with multiple units on one line, it is worth telling residents what is going down the sink, because one unit can block a stack for everyone.

Wipes and product

Solid mass, obvious once it comes out. Nothing structural is wrong with the pipe.

Worth a note to the resident rather than a repair. The only thing to check is whether the line has a section with a shallow fall, because a pipe that drains slowly catches things a properly graded one flushes through.

Sand, silt and soil

Grit coming out of a stormwater line usually means a broken pit or a section of pipe that has failed and is letting the ground in.

That one matters, because if soil is entering the pipe it is also leaving a void outside it. Left alone, that void grows and the ground above eventually drops. It shows up as a dip in a driveway or a section of paving that has settled.

This is the blockage worth investigating properly rather than clearing.

Nothing at all

Sometimes the drain clears easily and nothing significant comes out. That usually points at a fall problem, a sag in the line, or a partial collapse that traps water and lets anything passing through settle.

A camera answers it in twenty minutes.

What to ask for after a clear

Ask what came out. Ask whether the line was camera'd after it was cleared, and if it was, what the footage showed.

A clear with no diagnosis is a temporary result sold as a permanent one. On a single house that is an annoyance. Across a building with dozens of units on shared lines, it is a recurring cost that never gets traced back to a cause.

We handle drainage as part of plumbing, and on repeat blockages we would rather find the reason once than clear the same line four times. If a drain in a property you manage keeps coming back, tell us the history and we will start with the camera rather than the machine.