Sika 4a Waterstop is a rapid setting, ready to use waterproofing admixture which can be used to produce a paste for leak stopping against high water pressure infiltration when mixed with water and ordinary Portland cement.

• Ready to use – just add clean water and ordinary Portland cement
• Does not contain chlorides
• Solvent free
• Suitable for use in quick setting mortar for assembly work
• Rapid setting for quick leak plugging and/or fixing