I have begun to notice more than a few homes in and around my area that are having another layer of shingles applied over the top of shingles that are covered in black streaks, moss and lichen. I would think that this is going to cause the new shingles to degrade at a much quicker pace, not sure why any roofing company would even agree to do this.
Zach Maynard said
May 6, 2014
I think the majority of these companies know far less about these issues than we do. The bigger issue may be it spreading to the new roof quicker?
Patrick G said
May 6, 2014
I think a new roof would kill the G/M. But new roofs today are getting streaks at 5 years young.
Fred W said
May 15, 2014
I don't think there would be an issue with GM and probably not even an issue with lichen. Moss on the other hand would cause the shingles to raise a bit. I would also bet the moss would void the new shingle warranty but I'm not sure about that.
Zach Maynard said
May 16, 2014
I took some pictures of this scenario over the weekend I will hop on and post them. It showed the lichen dead and seemingly no affect to the new roof.
I have begun to notice more than a few homes in and around my area that are having another layer of shingles applied over the top of shingles that are covered in black streaks, moss and lichen. I would think that this is going to cause the new shingles to degrade at a much quicker pace, not sure why any roofing company would even agree to do this.