A Quick Look at Rigid Foam Insulation

In this video, Rise Founder Matt Daigle talks about insulation and teaches you what to look for from manufacturers.

Expanded polystyrene (EPS) is a rigid polystyrene foam board with a more open structure that is more permeable to humidity than extruded polystyrene. If you break a piece of EPS, you see its characteristic structure of little beads of foam all stuck together.

Rigid foam board insulation comes in a few different varieties - and one of its more popular versions is Extruded Polystyrene or XPS. It has a high insulation value to save energy, and it’s one of the few types of insulation that can be used underground, such as under a slab, or on the outside of a foundation wall.

It typically comes in 4x8ft boards or larger and offers R-4 or R-5 value per inch.

The glaring issue with this type of insulation, like many other types of insulation, is in its manufacturing process. XPS uses blowing agents (to make bubbles), and these blowing agents have a high GWP (Global Warming Potential).

Several manufacturers have remedied this by using low global warming potential blowing agents like carbon dioxide, water, or hydro-fluro olefins (HFO) to produce XPS.