Using Foamglas instead of polystyrene to insulate beneath our basement slab and on the foundation walls.
Photo Credit: Alex Wilson
In my role with Environmental Building News and our GreenSpec Product Database, I get plenty of opportunity to research and write about innovative building products. That’s one of the really fun aspects of my job.
On occasion I also get an opportunity to try out new or little-known materials. In the construction of our new home in Dummerston, Vermont—actually the rebuilding of a 200-year Cape—I’ve had opportunity to get some real experience with lots of products. One of these is a cellular glass insulation material known as Foamglas (check out Foamglas in GreenSpec).
Why we need a product like Foamglas
I’ve written often about the problems with extruded polystyrene from an environmental and health perspective. Relative to performance, extruded polystyrene (XPS) is a great product. It is water-resistant so can be used below-grade; it has high compressive strength so can be used beneath a concrete slab floor; it insulates very well (R-5 per inch); and it’s inexpensive. These properties make XPS the nearly universal choice for sub-slab and exterior foundation insulation today.