Concrete roof tiles are a durable roof material that will last nearly the lifetime of the home. Over the course of a year, leaves, limbs, dirt and other debris may collect in the valleys of the roof. To prevent mould and stains from forming a cleaning may be necessary on a yearly basis. There are professional services for this project available, but if you're not afraid of heights and have access to a power washer, doing it yourself will save you money.
Set up your pressure washer by hooking up the water supply to the unit. Turn on the water to get water moving through the machine. Attach the wand and fit it with a 25 degree tip. Turn on the machine and let the water run through the engine. Make sure you use a long enough extension hose so you can move about the roof freely.
Set up your ladder on even ground and climb up on the roof.
Stand on a dry portion of the roof.
Spray the water 12 inches away from the shingle, with the water aimed down the roof. Spray one shingle and inspect it for any damage.
Spray the entire roof in this manner to remove the dirt and debris.