Minimise the walking you do on your roof.
Walking on a roof when the shingles are brittle (in cold weather) or soft (in hot weather) can damage the shingles. If you have to walk on the roof to take care of a problem, try to do it at the most mild time of day – in the morning in the summer and the afternoon in the winter.Don't use a pressure washer.
A pressure washer will loosen the granules embedded in the asphalt shingles and expose the asphalt to UV rays which will shorten its lifespan. Only professionals should use a pressure washer to clean the roof.Don't use bleach to clean the roof.
Bleach can be corrosive and is not something that you want to get in the runoff, gutters and groundwater. If you have an algae problem then take these steps: Trim the vegetation around the roof so it gets more sunlight. Then apply zinc strips along the ridge of the roof. Zinc is not harmful and it will form a protective coating over the shingles to prevent algae.