Mop with water and a mild detergent such as dawn or simple green.

Water hose with brush/pressure washer. Caveat: Pressure washers should be used with adequate care, such as using a wide tip and maintaining a safe distance from the substrate. Soft washing with appropriate chemicals is also a great option for removing organic material. 

Depending on the level of UV exposure, one can expect to reseal overlays every 2-5 years. 

Prosoco recommended cleaning and guarding products/steps