Before Cleaning The Roof
An insurance company did a site visit of a new customer to finalize the underwritting of the policy. They requested that the roof be cleaned of organic material and it must be done promptly. Getting the call to clean the roof I let the customer know that I do not use a pressure washer to clean a roof rather low pressure application of a cleaning solution that kills all material on the roof that grows.
Arriving at the house there certainly was a lot of dark streaking on the roof and at the bottom of each shingle at the edge a bunch of growth was there. Looking at it since it was so low I thought it was lichen. But as I got closer and started to look it turned out to be moss that was lining the edge along the shingle. Sort of like a fringe.