Easy fixes for clogged drains

When a plunger won't remove a blockage in a drain, you need to brace yourself for an unglamorous job. Clearing drains may be dirty, but it could also save you lots of money in professional service fees.

Clear the trap

If you've tried plunging the sink and the blockage won't shift, the waste pipe is probably clogged with soap scum, hair, oil or kitchen waste. Waste-water outlet pipes are fitted with a U-shaped bend that traps water in the lower part of the "U" and so prevents smelly sewer gas from entering the building. It's here that you're likely to find the source of your blockage.

• Remove the U-bend, or trap. It will most likely be connected to the sink and to the waste outlet pipe with large plastic nuts. Loosen the nuts by hand, or turn them with a pair of locking pliers if they prove stubborn. Place a bowl beneath the trap to catch the water it contains.
• Take care not to lose any rubber seals or washers when removing the trap. Make note of where they go so you can reassemble the trap.
• Once you have removed the trap, clean it thoroughly with a bottle brush, detergent and hot water. Shine a flashlight down the open end of the waste pipe and remove any further debris using a hook made from a length of coat-hanger wire.
• Smear petroleum jelly on the threads of the trap nuts before reassembly — this will make them easier to remove next time.

Remove a blockage further down the pipe

If the drain is only partly blocked, try a chemical unblocking agent. These caustic chemicals are toxic and can cause skin irritation, so always follow the instructions on the bottle and be sure to wear rubber gloves, cover any exposed skin and ventilate the room adequately.

Avoid caustic chemicals if the drain is completely blocked — they can damage plumbing fixtures. Instead, use a plumber's snake. This is a length of coiled wire that can be wound into the drain — even round corners and bends — to push through a blockage further down the pipe.

Keep your waste pipes flowing freely

When it comes to drains, prevention is always better than a cure.

• Buy a sink strainer for your kitchen sink and use it when doing the washing up; it will trap food particles before they reach your drains.
• Avoid pouring oily liquids down the drain — they can solidify and cause a blockage. Instead, pour them into a sealable plastic bag and dispose of them in the household trash.
• Use boiling water to melt built-up grease. Once every two weeks, pour a pan of boiling water down the drain. Once a month, pour half a cup of baking soda down the drain, then slowly add a cup of white vinegar. Leave for a few minutes, then flush away with boiling water.