That shit wore like iron too. If you drive around older parts of cities and towns, occasionally you'll see "fishscale" shingles on homes from the 1910s and 20s with steeply pitched roofs. Those are asbestos cement as well, and they wear like iron as long as they aren't hit by large objects. There's a section of town in Cape Girardeau, MO that has a neighborhood that used these in the original construction. About 1/3 of the houses still retain the original shingles/roof. Some are a bit mossy, but they aren't leaking. Good shit as long as you don't break them and breathe the dust.