Additive for Mortar and Screed

  • Universal use
  • Improves water resistance and bonding strength
  • Reduces water absorption of porous substrates

MULTIPURPOSE PRIMER AND ADDITIVE is a water dispersion primer and additive designed to improve shear and tensile bond of sand/cement screeds, plasters, render mortars and tile adhesives.

It is used for treating porous substrates and materials.

Thus, it can be used as a primer and additive to prevents gypsum substrates from breaking off from the chemical reaction between gypsum and cement aluminates; and to improve strength of cement/sand, mortar/screed.




12 months if stored under the right conditions in unopened packaging.

In general, the surface being adhered to must be clean, dry, free of dust, dirt, oil, grease and contaminating materials. New brickwood and walls should be left at least 7 days prior to rendering.


  • First apply a slurry coat using a roller, brush or a flat trowel, to a maximum thickness of 15 - 20mm that may require 2 applications. While the slurry coat is still wet, apply render over it. Ensure firm pressure on the trowel to work with the render into good contact with the surface.
  • Renders are applied in the normal manner up to 13mm thick and allow to take initial set. Renders in excess of 13mm should be applied in a two coat operation.


  • First apply the slurry coat using a roller, brush or a flat trowel, to a maximum thickness of 2mm. while the slurry coat is still wet, apply the screed mix. Using the straight edge, trowel or timber batten to level the screed. Recommended minimum thickness of screed 15mm. Screed should be left with a good float finish to create a key for tiling / waterproofing.

5l of MULTIPURPOSE PRIMER AND ADDITIVE covers approximately:

  • RENDER COAT: 10m2 at bed thickness of 10mm
  • SCREED: 9m2 at bed thickness of 15mm, 3m2 as a self
    supporting screed at 40mm