It is a periodic cleaning and maintenance of areas which are outside the scope of daily cleaning routine due to inaccessibility or need to use specialised personnel, equipment and chemicals. This involves the regular descaling and disinfecting of all sanitary fittings and associated pipework e.g. clearance of pipe blockages and maintenance of cisterns and taps in the washrooms. The aim is to minimise the health risk to users of the facilities and to provide conditions that are pleasant to use.