Source for XPS/EPS for conditioned attic

I am in zone 5 building a conditioned attic house w 12:12 metal roof with rockwool inside (prob R30). I need to put R20 of rigid foam on top -… I am in zone 5 building a conditioned attic house w 12:12 metal roof with rockwool inside (prob R30). I need to put R20 of rigid foam on top -…Read MoreGreenBuildingAdvisor