Rigid Foam Boards
Rigid foam boards are commonly used to insulate newly-constructed floors, walls, and roofs of a house. The boards are fastened into place, and provide strong thermal resistance while reducing conduction by structural elements.
Rigid foam boards can be cut to fit uneven spaces, providing complete coverage of targeted areas.
Rigid foam boards are petroleum-based, and are available in three forms: Expanded Polystyrene (EPS), Polyiso (ISO), and Extruded Polystyrene (XPS).
Expanded Polystyrene (EPS)
- Rated at R4
- Has a higher R-Value per dollar than XPS
- Type 2 vapour retarder
- Used to insulate walls where trapped moisture is a concern
Polyiso (ISO)
- Rated at R6 to R6.5
- Polyiso’s internal temperature must be above 15 degrees Celsius to retain R-Value
- Formed from a liquid foam
- Impermeable, can cause moisture damage if installed in the wrong places
- Often coated in foil, allowing the board to act as an air and vapour barrier
- Most eco-friendly option
Extruded Polystyrene (XPS)
- Rated at R5
- Hydrofluorocarbon (HFC) is used as blowing agent; less harmful blowing agents are being developed
- A vapour retardant is necessary to prevent flammable
- Can act as air barrier when taped
- Neither absorbent nor reactant to moisture
- Loses effectiveness over time due to “off-gassing”
To determine the material that best fits the needs of your home, speak to a technician at One Alliance Insulation today.
