We've just got ourselves a petrol pressure washer as we have been getting asked to do patio and decking cleaning from a number of established window customers. What is the going rate for this work, we were thinking along the lines of £25 per hour? Is this too much? Or would we be better doing it by pricing per square metre? Anyone who's currently doing this I would really value your input. We not looking at sealing or repairs, just pressure washing the dirt off. (We have a round patio head cleaner too)