For all that we know about roofs - which is a great deal - sometimes things can get confusing. I am more than partly to blame for that. I wrote a lot of the code language dealing with both vented and unvented roof assemblies. Yes, the language is confusing. I am going to focus on unvented roofs and hybrid roofs. Not on vented roofs in the strict use of the term vented roof. In this column, Joe clears up a few things about roofs.