I am looking at insulating my approximately 100 year old home. There is currently NO insulation in the crawl space or the walls. I do have fiberglass insulation in the attic - currently about R-19. I live in Asheville, NC. I have had a couple of companies out with estimates. Everyone seems to have a different idea about the best way to achieve thermal efficiency. Most recently I looked at RetroFoam. I am finding very little about it other than the company website, and a slew of articles about a class action suit in Ontario. Apparently it is illegal to use anything with formaldehyde in Canada. I've reviewed your archives comparing spray foam with cellulose, but the RetroFoam may be something entirely different. I would love feedback. Is anyone familiar with RetroFoam?