Class R3 General Purpose Structural Repair Mortar (EN1504-3, DWI 31, BBA, WRAS)


Monomix is a low density, high strength, shrinkage compensated, waterproof mortar for the structural repair, rendering and profiling of vertical, horizontal and overhead surfaces.

Monomix is a single component cementitious repair mortar which incorporates the most advanced cement chemistry, microsilica, fibre and styrene acrylic copolymer technology. This results in a rapid hardening, low density, high strength mortar with enhanced polymer properties. The thixotropic nature of the product enables easy high build trowel application for the structural repair of voids and the rendering and re-profiling of both vertical, horizontal and overhead surfaces. The product is supplied as a single component system ready for on-site mixing and use, requiring only the addition of clean water.


  • Incorporates the latest proven cement chemistry, microsilica, fibre and styrene acrylic copolymer technology
  • Pre-packaged material requiring mixing with clean water on-site to give an easily trowellable mortar with maximum application thickness of 80mm in vertical, horizontal and overhead situations
  • High bond strength exceeds tensile strength of concrete, thus ensuring monolithic performance of the repair
  • Dense matrix offers low permeability to water, even at 10 bar pressure, and very high diffusion resistance to acid gases and chloride ions
  • Improved tensile and impact strength. Excellent low sag properties
  • Non-toxic when cured and is listed as authorised under Regulation 31 for use in the supply of drinking water
  • Economic repair mortar generally requiring no substrate or inter-layer priming. Part bags can be mixed
  • Easily overcoated with specialist membranes to provide further protection and aesthetic quality.


CE marked in accordance with BS EN 1504 Part 3. Fully complies with the Highways Agency Standard BD 27/86 for the repair of Highway Structures. Approved by the BBA, Certificate No. 05/4276. Listed under DWI Regulation 31 for drinking water applications. Compliant with LU Standard 1-085 ‘Fire Safety Performance of Materials’.

Specification Clause

The repair mortar shall be a single component cementitious mortar, incorporating microsilica, fibre and styrene acrylic copolymer technology, and shall be CE marked in accordance with BS EN 1504-3 Class R3. It shall be BBA Certified and comply with the following performance specification:

  • 5-80mm application thickness in a single layer even overhead
  • Impermeable to water under 10 bar hydrostatic pressure such that 5.7mm of mortar is equivalent to 1000mm of concrete
  • Oxygen diffusion coefficient to be no greater than 2.72 x 10-4 cm2/sec.
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