I noticed over the weekend that I am getting a build up of moss on my back
porch roof. The roof is under trees and gets very little sun.

Will the moss shorten the life of the asphalt shingles?

Is there a way to get rid of the moss? Some people recommended that I
should spray the roof with a bleach solution to get rid of the moss. Would
this be a good idea?

Thanks

I think there are products that are specifically for this and would be better
than bleach. Also, I read in an old home repair book that you can string bare
copper wire back and forth across the roof. As the copper rusts, the oxides
created are an anti-fungal agent. That is why you can see copper flashing on
old church roofs.

Good luck.