"As a side note, I always wondered why metal roofs are not more popular. Aluminium would last pretty much forever, and it doesn't have to be one piece - you can

"As a side note, I always wondered why metal roofs are not more popular. Aluminium would last pretty much forever, and it doesn't have to be one piece - you can make it into shingles for easy installation." When I re-shingled my roof a couple of years back I looked into metal roofing. The cost was almost double asphalt roofing shingles. Although a metal roof would last longer (25 years vs. 50 years), but if you wanted durability and cost wasn't an object slate roofs are expected to last 75 years or more (at least here in Maine). Of course a white roof here is useless -- I don't even own air conditioners.