Most blocked drains are not bad luck, they are the slow result of what goes down them. The good news is that means most are preventable. A handful of simple habits stop the large majority of household blockages before they start. The important caveat first: if your drain blocks again and again no matter how careful you are, prevention is not your problem, you have a structural fault underground and you need a camera, not better habits. We cover that case at the end.
The kitchen, fat is the enemy
The single biggest cause of kitchen drain blockages is cooking fat and grease. It pours down warm as a liquid, then cools and sets hard on the inside of the pipe, narrowing it a little more with every wash-up until the drain chokes. It also grabs everything else that comes past, food scraps, coffee grounds, and builds a solid plug.
- Never pour fat or oil down the sink. Pour it into an old jar or container, let it set, and bin it.
- Wipe greasy pans with paper towel before washing.
- Fit a sink strainer to catch food scraps. Empty it into the bin or compost.
- Run hot water through the drain for a few seconds after washing up to keep residue moving along.
- Keep coffee grounds, rice and pasta out of the sink, grounds accumulate and rice and pasta swell.
The bathroom, hair and soap
Shower and basin drains block on hair bound together with soap scum into a felt-like mat that catches everything else.
- Fit a hair catcher over every shower and bath drain. Clear it regularly into the bin. This one cheap thing prevents most bathroom blockages.
- Do not rinse hair clippings from a haircut or beard trim down the basin.
- Use less of the gloopy stuff where you can, thick conditioners and bath oils add to the scum.
The toilet, only the three Ps
The rule is simple and worth putting on a sticker if you have a busy household or a rental: flush only pee, poo and toilet paper. Everything else belongs in the bin.
- Wipes, including the flushable ones, do not break down and are a leading cause of blockages. Bin them. We explain exactly why in are flushable wipes actually flushable (short version, no).
- Sanitary products, nappies, cotton buds, dental floss all stay intact in the drain and snag.
- Paper towel and tissues are not toilet paper, they do not disperse the same way. Bin them.
- Keep a small bin in every bathroom so binning is the easy default, not flushing.
Outside, mind the trees
Outdoor and main drains block from leaves, dirt and, the big one on the Gold Coast, tree roots finding their way into the line. You cannot prevent root intrusion with habits if the pipe is already cracked, but you can avoid making it worse:
- Keep drain pits and grates clear of leaves and debris, especially before the summer storm season.
- Think before planting thirsty, aggressive trees right over a known sewer run.
- Know where your drains run so you are not planting or building over them. A camera survey with a sonde locator can map the line if you do not have a drainage diagram.
Holiday lets and busy households
Short-stay guests treat toilets like bins, so holiday-letting properties block more than owner-occupied homes. Clear bathroom signage (flush only toilet paper, bin everything else) and a visible bin in each bathroom genuinely cut the callout rate. For body corp buildings, a shared sewer stack can back up into several units from one careless flusher, so the prevention message is worth pushing building-wide.
Septic and AWTS owners, stricter rules
If you are on acreage with a septic tank or an aerated wastewater treatment system, the rules are tighter than for town sewer. Wipes, sanitary items and excess food waste clog the inlet and overwhelm the biological treatment, shortening service intervals and risking expensive system failure. Stick rigidly to the three Ps and keep up your scheduled pump-outs and servicing.
What about chemical drain cleaners?
The supermarket caustic drain cleaners are a band-aid we do not recommend as a routine fix. They can clear a soft partial blockage, but they do nothing for roots, do not touch a structural problem, and the harsh chemicals sit against your pipework and can damage older drains and your traps. They also make life unpleasant and hazardous for the plumber who has to clear the drain properly afterwards. If a drain is slow, a plunger and hot water are safer first steps. If that does not fix it, call us rather than pouring in more chemicals.
When prevention is not the answer
Here is the honest bit. If your drain keeps blocking every few months despite good habits, no habit will save you, because the cause is structural. Almost always it is tree roots entering a cracked joint in an older drain. Each clear (roughly $200-450+ by jetter) buys you a few months before the roots grow back and re-block. The only permanent fix is sealing the cracks the roots come through, which usually means no-dig pipe relining, the jointless liner is root-proof. We go through this pattern in full in why your drain keeps blocking every few months, and the way to confirm it is a CCTV camera inspection.
The simple checklist
- Bin fat, oil and grease, never down the sink
- Strainers in sinks, hair catchers in showers
- Flush only the three Ps, bin wipes and sanitary items
- Hot water through the kitchen drain after washing up
- Keep outdoor pits and grates clear
- Septic and AWTS, stricter rules and regular servicing
- Recurring blockages despite all this, get a camera survey, it is structural
For more, see the blocked drains pillar and our blocked drains service. If a drain is already blocking regularly, do not keep paying for clears, get in touch and we will find out why it is happening.