This concrete repair mortar is based on a Natural Cement based binder, it is an environmentally friendly, fast setting, high early strength concrete repair material that starts to set in 35 minutes. NATCEM 35 only requires to be added to water and mixed for 2 minutes (see mixing instructions for further details), and unlike most other manufacturers products it does not require primers, bonding agents and or curing agents. It can be used in cold & wet conditions, sets under water and can be, if required, from a minimum of 10 mm built up layer on layer to any thickness. It is also Reg.31 approved for contact with drinking water with only ½ hour curing period after set required.