
Types of Rigid Foam Insulation
There are many types of rigid foam insulation material, but the most common ones include Polyisocyanurate (Polyiso), Extruded polystyrene (XPS), and Expanded Polystyrene. There’s also mineral wool which is more environmentally friendly. However, it fails to act as an air barrier and generally costs more.
The rigid foam insulation’s best performing material is Polyiso which has an R-value of 6.5 per inch. It is the highest R-value amongst rigid foam insulation materials, whereas XPS has an R-value of 5.9 and EPS with 5 per inch. Polyiso is an excellent material due to its flame-retardant capabilities and eco-friendly chemical makeup. It is, however, expensive and prone to moisture accumulation.
EPS is one of the best rigid foam insulation types as it is inexpensive and can be used in closed corners. XPS, on the other hand, is used as concrete forms. Once the concrete cures, this rigid foam insulation prevents energy dissipation through the slab.