Why Does Your Kitchen Sink Keeps Blocking?

7 Reasons Your Kitchen Sink Keeps Blocking

1. Grease and fat

Sydney Water says fats, oils and grease harden in pipes and can combine with unflushable waste to form fatbergs. It advises collecting cooled fat in a sealed container for the bin and using sink strainers.

2. Food scraps

Rice swells, pasta clumps, and coffee grounds settle like sand. Together with grease, they make a plug.

3. Soap and detergent scum

Soap residue sticks to grease and builds a sticky coating that catches everything else.

4. A partly blocked branch drain

Clearing the waste near the sink leaves the build-up deeper in the pipe, so it comes back the next time you wash up.

5. Poor fall or an old, rough pipe

Waste needs a steady slope to flow away. A pipe with poor fall, or an old pipe with a rough inside, holds onto debris.

6. Tree roots or a damaged pipe

In houses on a ground-floor slab, the kitchen waste line can run through the yard before it reaches the sewer. Roots, cracks and sagging sections there will cause repeat blockages. See how tree roots get into sewer pipes.

7. A shared line

In units and townhouses, the kitchen drain often joins a shared stack. If neighbours have the same problem, the blockage may be in common property, so talk to your strata manager before you call a plumber.

Are Home Remedies Enough?

For minor blockage, yes, sometimes. Try this order:

1. Remove visible debris from the strainer and waste outlet.
2. Use a plunger with the overflow blocked and enough water to cover the cup, with firm, steady strokes.
3. Flush with hot tap water, not boiling, since very hot water can stress some plastic pipes and fittings.
4. Avoid chemical cleaners. They rarely reach a blockage further down, can damage older pipes and fittings, and are a hazard for the plumber who has to work in the water afterwards.

If it clears and then comes back, the home remedy isn't solving the cause. Our blocked sink and toilet service explains what a professional clear involves.

When a Kitchen Sink Blockage Needs Professional Help

Call a licensed plumber if:

• the sink blocks again within weeks of clearing
• more than one fixture is slow or gurgling
• smells are getting worse
• water is backing up into other drains
• you've plunged properly and nothing moves

A plumber will clear the line with high-pressure jetting or a cable machine, then run a camera through to look for scale, roots, a sagging section or damage. If the pipe is cracked or invaded by roots but still holds its shape, pipe relining can repair it without digging.

If sewage is coming up in other drains, or several fixtures are affected, read about blocked sewer repair.

How to Stop Your Kitchen Sink Blocking Again

• Let cooking fat cool, collect it in a sealed container and put it in the bin
• Wipe greasy pans with paper towel before washing
• Use a fine sink strainer and empty it into the bin
• Keep coffee grounds, rice, pasta and fibrous scraps out of the drain
• Run hot tap water after washing greasy dishes
• Act early on slow draining
• Book a camera inspection if blockages keep returning

Need Help With a Repeated Sink Blockage in Sydney?

If your kitchen sink keeps blocking, Sydney Drain Surgeons can inspect the line, clear the obstruction properly and check whether there is a larger issue in the pipework. Call 02 9190 6765 or request a free quote online for help anywhere in Sydney.