Rigid foam wall insulation is gaining popularity in the insulation world. It is a great option for insulating the walls of your home. It eliminates air movement, doesn’t absorb moisture thus eliminating mold issues, and stays in place once installed, all of which results in a high R-value that will last. It is most often used on masonry walls, since it is easy to install and works great in basements and crawl spaces.

Types of rigid foam insulation:

  • The first type of rigid foam board is polyisocyanurate, or polyiso. Polyiso has the best R-value at R-6 per inch for rigid foam board and so is the most expensive. It also has foil on both side, so it can also be used as a *radiant barrier* if needed.
  • Extruded polystyrene, or XPS has a smooth plastic surface and has a great R-value at R-5 per inch
  • Expanded polystyrene, or EPS is the least expensive option for rigid foam boards. It is still very efficient with an R-value of R-3.8 per inch.