What to Know About Polystyrene as Roof Insulation

If you need to re-insulate your roof, you have several choices in roof insulation. While fibreglass is the traditional roof insulation, you can also choose polystyrene. However, polystyrene isn't for everyone or every roof. Keep reading to learn more about different types of polystyrene and how it compares to fibreglass as a roof insulator.

What Is Polystyrene Insulation?

Polystyrene is a versatile plastic used in many different applications. In insulation, you generally find two different types: Extruded and expanded.

Extruded Polystyrene

Extruded polystyrene contains added materials like resin. It is heated to a liquid form and sent through a die to create a specific shape. Once cooled, it is closed-cell so it contains less air and is more resistant to moisture.

Expanded Polystyrene

Expanded polystyrene starts as polystyrene beads pressed together in a mould. Applied heat expands the beads, so they bind together. The result is a sheet of material with more air cells.

Where Is Polystyrene Insulation Usually Used?

Polystyrene is most commonly used in areas of the home where moisture accumulates. It makes excellent roof insulation, but economical fibreglass is more popular. You will likely see polystyrene on flat roofs. These roofs have limited space for insulation. Plus, polystyrene has high compression tolerance.

What Are the Benefits of Polystyrene?

Both extruded and expanded polystyrene have excellent benefits for roof insulation. Extruded polystyrene has a higher R-value than expanded polystyrene. It also has good heat resistance, making it great for hot climates. Expanded polystyrene has excellent moisture control.

Polystyrene is very lightweight and easy to handle. The roofer can cut and install the sheets quickly. Even though it's lightweight, the material is very strong and durable. It can last for decades when installed correctly.

How Is Polystyrene Compared to Fibreglass?

Fibreglass is one of the most commonly used roofing materials. It is especially popular with large attics and slanted roofs. While it has proven qualities, it has some drawbacks. The material is bulky and difficult to handle compared to polystyrene. Plus, it has tiny fibres that can become loose.

Polystyrene holds up better against mould and moisture than fibreglass. Roofers can also easily modify the material without special tools. People don't have to use special suits or gloves to handle polystyrene. However, roofers need special equipment to ensure they don't breathe in fibres.

Polystyrene is a durable, effective, and easy-to-install roof insulator. It is durable and insulating whether you have a wet or dry climate. Both polystyrene and traditional fibreglass are easily available. If you want to know more about each kind, contact a roof insulation contractor or retailer who can help.