Originally posted by PakaNoHida:

Unless you use the tarred roofing material, it will always weather, however as I am visualizing it, you should have no problem with what you are trying to build, but screenshots would help everyone here.

No it doesn't. I just checked the roof on my main base and after 300h of playtime, it doesn't have a single scratch, i literally can't repair it. Maybe you have some mod installed that makes the roof deteriorate, but mine doesn't.