On Thu, 13 Nov 2003 18:14:44 GMT, "racarson"
wrote:

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?

Yes because it retains moisture and doesn't let the shingles dry out
after wet weather.

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?

You've gotten various answers in this regard. My only addition is to
suggest zinc strips installed just below the topmost course of
shingles; the rainwater runs off the strips and changes chemical
composition to become hostile to moss.