Plasticising and waterproofing admixture which is added to concrete and/or mortar mixes to form a permanent water repellant lining of calcium stearate in situ, on the walls, pores and voids of concrete mixes.


In concretes, renders and mortars, above and below ground level, to assist in making water resistant areas, such as basements, tanks, lift wells, tunnels, planterboxes etc.


  • Rapidly dispersible
  • Improves workability
  • Increases durability of concrete
  • After trade bonding not affected
  • No significant strength reduction in concrete


 Specific Gravity at 25’c  approximately 1 -13
 pH  approximately 10.0
 Flash Point  Not applicable


All surfaces to which the render is to be applied must be structurally sound and clean.  Old concrete basework must be revealed by scrubbing.  New concrete and brickwork must be scabbled and wire brushed with joints raked.  Thoroughly wet the area to be rendered and ensure that premature drying out, of the surface does not occur.


Interproof is added to mixing water at the rate of 1 litre (Interproof) per 30 litres of water.  Use 3 parts plastering sand/1part cement and mix thoroughly.


All concrete to be waterproofed shall be a minimum of 20 MPa design and shall be integrally waterproofed by the addition of Interproof as supplied by Westlegate Pty Ltd used in strict accordance with the printed instructions.


Clean all tools and equipment with clean water immediately after use.


Container Size: 5 Litre & 20 Litre containers.


Where surfaces are to be tiled, avoid the use of excess Interproof and excessive floating or trowelling.  The proper use of Interproof will give durable water resistance to a relatively high pressure of water, however such applications are not impervious to water vapour.  Avoid excess water in mixes, otherwise shrinkage cracks, water permeability and defective bonding will result.  Avoid repeated and prolonged skin contact with Interproof.


Refer to Westlegate Pty Ltd Material Safety Data Sheet (MSDS) for instructions.