CeraZorb is a synthetic Cork Underlayment for use under Ceramic Tile & Natural Stone Flooring. Many years of research & testing went into CeraZorb and we feel it is the next generation in cork technology. CeraZorb will not rot, swell or absorb water and has achieved the same acoustic impact insulation ratings as 1/2" natural cork at about half the cost.  CeraZorb is lightweight only 40 lbs per roll and is available in 4' x 100' rolls.