Types of Roof Insulation and How to Determine If Your Attic Needs More

Insulating your roof helps keep your house cool in summer and warm in winter, saving energy and extending the life of your heater and air conditioner. There are different types of roof insulation, and the best type for you depends on your location, your budget, and your home’s design. This article will explore seven popular types of roof insulation, as well as how to determine if your attic needs more insulation.


The thermal resistance of insulation is measured by its R-value, and it’s important to understand how R-value is determined. It’s also helpful to understand the types of materials that are used in insulation, how they perform, and their R-value.

Some common insulation materials include glass rock or mineral wool that is made from melted rocks and spun into wool, usually with binding agents; fiberglass insulation which is manufactured using cotton, sheep’s hair, or other natural fibers that are then spun into sheets, bonded together, and coated with foil; and foam plastic insulation such as expanded or extruded polystyrene (EPS and XPS). Foil-faced batt insulation is often used in cathedral ceilings to prevent moisture accumulation.

Spray polyurethane foam is another popular form of insulation for a roof, which has an excellent R-value, good dimensional stability and fire resistance. It can also be applied quickly and effectively, which makes it a good choice for sloping roofs. Polyurethane can be sprayed directly onto surfaces, which can make it easier to insulate tricky areas like vaulted ceilings or dormers. Many spray polyurethane products use blowing agents that are low in HCFCs and CFCs, which meets environmental goals.