Patio pressure cleaning. If your patio or garden path is dangerously slippy or dirty, pressure cleaning will remove, dirt, slime, grime and green algae from all types of hard standing areas around your home, making them SAFER and dramatically IMPROVING THEIR APPEARANCE. It is suitable for use on paving flagstones, block paving, concrete, natural stone or tarmac. No harmful acids are used in the cleaning process, and all the materials are completely bio-degradable and harmless to birds, animals and plants. As well as the above, pressure cleaning has many other applications. including exterior cleaning of buildings and tiled house roofs, also garden walls and garden furniture – the applications are unlimited.