Patrick tells us a little more about how moss growth can really harm the roofs that takes such good care of you.
To hear the first part of the explanation go to Moss Growth on a Composition Roof Part 1
To read the script of this video, see below.
Okay, this is what I’m talking about when I say you let the moss get serious on here. This roof will fail two to three times sooner than it should, just because they’ve let this moss form in these keyways, and it will get underneath that shingle and it will lift it up. Remember, these shingles are designed to traffic water vertically, running up and down the shingle – actually down the shingle. They’re not designed to handle water trafficked horizontally on the shingle. Moss, debris, buildup, tree debris, and stuff like that, that will actually cause water to travel horizontally and find fasteners and get into the structure.