Installing insulation at the roof is an important step for protecting the home from moisture intrusion and energy loss. Read about how to inspect homes that use high-efficiency spray foam in Inspecting Spray-Foam Insulation Applied Under Plywood and OSB Roof Sheathing.
I just finished an article on fiberglass insulation. In it you can learn about the history of fiberglass, how it is made, its strengths and weaknesses as an insulator, associated hazards, and the insulation alternative cellulose.
I hope this is useful!