The DOFF system is an expertly engineered system that utilises steam to remove some of the more resistant forms of dirt or markings from a number of surfaces. The use of steam offers a gentle clean and will not cause damage to the surface being cleaned. The DOFF system only uses 5ltrs of water per minute whereas a pressure washer normally uses 15ltrs per minute. Therefore the DOFF system is far more energy efficient. An additional benefit is that the surface is dry within minutes, which prevents any long term damage due to trapped moisture. The DOFF system is fully approved by English Heritage.