How does spray foam insulation expand?
How does spray foam insulation expand? My husband and I recently hired a certified spray foam insulation installer to install spray foam insulation in our home. We had purchased an older home, and it needed new insualtion. The old insulation was not performing effectively, and we weren’t even sure if enough insulation had been installed to begin with. We hired a professional to remove the old insulation and replace it with spray foam insulation. I think the entire concept is amazing, but I just don’t understand how it works. I know that the chemicals react and expand, but I just don’t understand how two liquids can turn to an expanding foam once they come into contact with one another.