Mataproof CEMflex Steel Plate Waterstop

CEMflex is a steel plate waterstop encapsulated in a patented, active coating which reacts with water and moisture when embedded in concrete to provide a watertight construction joint. It functions as both an active and passive barrier to the transmission of water through all non-movement construction joints (horizontal and vertical) in in-situ reinforced concrete. CEMflex may be used in both pressurized and non-pressurized water. 

System Benefits:

  • Active coating reacts with alkaline water and moisture to provide infinite sealing ability
  • Excellent bond to concrete
  • Only 3 cm of concrete cover on both sides are necessary to seal cold joints up to 8 bar (80 m water pressure)
  • Bonding the overlaps is not required; overlap minimum of 5 cm held in place with provided clips
  • Easy to install through reinforcing cage; or embed into freshly poured concrete, saving up to 80% of the time to install traditional PVC waterstop
  • Rigid structure prevents collapse of waterstop from subsequent concrete pours


  • Construction joints in wall/floor areas in contact with pressurized and non-pressurized water
  • Wall/wall and floor/floor construction joints or wall/celing areas
  • Joints between prefabricated components: wall/floor, corner joints, and predetermined breaking points


Document Downloads