We use a proprietary cleaning mixture that is applied to your roof with a diaphragm pump not a pressure washer.
Soft roof cleaning.
The non bleach green eco friendly low pressure roof shampoo roof cleaning method uses a proprietary soap that is specially formulated and buffered to be safe on all asphalt and fiberglass shingles.
We also do not drag machinery up and down your roof to clean it.
Soft wash roof cleaning roof cleaning should never be done with a pressure washer.
So to get in front of the question of a pressure washer the term soft wash roof cleaning became one of several roof cleaning buzzwords.
All these terms mean is a sensible use of pressure to rinse the roof without damaging the shingles or roof tiles.
Only soft wash your roof.
The main culprit of most roof staining that causes prevalent black streaks is a bacteria called gloeocapsa magma.
There is no brushing scraping or power washing.
So to answer your question.
Algae growth staining and any other type of bacterial or fungal infestations are required to be cleaned or removed from the shingles in order to maintain their issued warranties.
High volume low pressure rinse roof shampoo and others.
More specifically we use small 12 volts pumps that deliver an eco friendly biodegradable treatment onto your roof and let the solution do the work.
It will not harm any landscaping around the home yet is 100 effective at removing roof stains from algae.
Soft washing is more than roof cleaning.
Verify your downspouts are connected to a gutter below.