Cooking fat, oil and grease
Hot fat looks liquid, but it cools and sticks to the pipe wall. More waste catches on the layer until the drain narrows or blocks.
Let fat cool, scrape it into a container and put it in the bin. Wipe greasy pans before washing.
Wipes, nappies and sanitary items
Many wipes stay strong in water. They twist together, catch on joints and combine with fat to make stubborn blockages.
Only flush toilet paper and human waste. Put wet wipes, cleaning wipes, nappies, cotton buds and sanitary products in the bin.
Food scraps and coffee grounds
Small scraps collect in traps and combine with grease. Coffee grounds do not dissolve and can form dense deposits.
Use a sink strainer and empty it into food waste or the bin. Do not rely on hot water to carry grease away.
Paint, solvent and strong chemicals
These products can harm people, pipework, treatment systems and the environment. Never mix drain chemicals, because dangerous gases or heat can result.
Follow the product label and Leeds disposal guidance. A blocked drain containing chemicals creates an extra risk for anyone opening it.
Cement, plaster and grout
Building products can set inside a pipe. Even wash water from tools can leave hard deposits that normal jetting cannot remove.
Use proper washout and waste disposal. Tell a drainage engineer if building material may be in the pipe so they can choose safe equipment.
Leaves, soil and garden debris
Leaves and soil collect in gullies and surface-water drains. Clear safe, reachable grates before heavy rain and keep loose material away from them.
Do not lift a heavy or unsafe cover. A private gully that stays full may need professional cleaning.