What is the best way to insulate a crawl space?
I have a concrete floor in my crawl space under an addition (the rest of the house is on concrete slab). There is no ductwork, there is a sump pump, and the wall joists above the foundation have spray-foam insulation. Since we moved in, I know that the addition's floor is very cold in the winter and in the summer we don't really have to use air conditioning because of the crawl space temperature. It is a wood floor on the other side of the crawl space ceiling. I haven't insulated because I read different articles and didn't want mold. But now I really need to do something, it's so cold in the winter. I'd like to do something ecologically good. I've been looking at a product called Reflectix, but not sure if this will be good. Any and all suggestions appreciated.