Hello Malleron,

You raise a very valid point with your concern for gassing.  Yes many adhesives do emit gasses that are harmful to the environment.  The great things about the adhesives we use on site are all water bourn. The drying process is an evaporation of the water in the adhesive. We did experiment with an epoxy at one time but scraped the idea due to environmental concerns. As for the Weathered Stone product itself the base structure is produced using primarily a material made of gypsum, which dries again by evaporation of the water content.  The strengthening additives we refer to in our marketing material are also water bourn.  Thanks for your concern with this issue.  It is not one many people think about.