Roxul ComfortBoard IS has some important environmental and performance advantages over XPS and polyisocyanurate insulation
Photo Credit: Roxul
Readers of this Energy Solutions blog may be aware that I’ve been critical of some of our foam-plastic insulation materials. I’ve come down hardest on extruded polystyrene (XPS), which is made both with a blowing agent that contributes significantly to global warming and with a brominated flame retardant, HBCD, that’s slated for international phaseout as a persistent organic pollutant.
So I’m always keeping an eye out for alternatives. I’ve written here about two of those alternatives that I’ve used in our own home: a cellular glass material called Foamglas with high compressive strength that works very well below-grade; and Thermacork, an all-natural rigid insulation material made from expanded cork.
I like both of those materials a lot, but they have two big problems: high cost and limited availability. They just won’t be able to enter the mainstream home building industry—not yet, anyway—since they cost more than twice as much as XPS and polyisocyanurate and are hard to get hold of.