Mould and algae on the exterior of your roof can still pose a health risk inside your home. When left unchecked, the mold and algae infestations can move from the roof to the attic before spreading through the rest of the house.
The mould spores may even enter the ventilation system, making it easier for the spores to spread to every room in your house.
Pressure washers can clear these infestations before they create a major health risk. It is much easier to blast mold and algae off your roof compared to removing mould and algae growth throughout the inside of your property.