Metal flashing under shingles?
We are about to roof a newly constructed barn. I have noticed on an older building we have that no moss grows below skylights that have metal flashing but grows heavily elsewhere. I was wondering if anyone inserts a row of metal under the top row of shingles the whole length of the roof to prevent moss growth. It seems like a good idea to me. If I did it does anyone have any experience with doing so? If so what type of metal. I think the flashing around the skylights was just galvanized metal. Thanks for your help. Lynne