Under every plughole in your home is a U-bend, with a small amount of water standing in the base that acts as a barrier against gases and germs passing back up the pipe from the waste outlet system. With the increasing strain put on domestic waste systems from dishwashers, showers, washing machines and waste disposal units, it's becoming more and more important to carry out routine cleaning and maintenance to your plugholes and pipes to keep germs and blockages at bay and avoid costly plumber bills.