The LiveRoof® system weighs approximately 27-29lbs./sq. ft. (with a media depth of 4”) when fully vegetated and saturated.  The LiveRoof® soil follows FLL standards, enhanced to reflect current research regarding sustainable organic content.  We have intentionally avoided excessive organic content, which will shrink excessively over time due to decomposition.  Likewise, we have avoided perlite which may break down during the freeze thaw cycle.