Renderoc HB70 horizontal


High-performance high strength, concrete patch repair mortar conforming to the requirements of EN 1504-3 Class R4. HB70 is designed for the reinstatement of localised patch repairs and larger areas where suitable reinforcement is incorporated. Renderoc HB70 is alkaline in nature and will protect embedded steel reinforcement. It is specifically designed for locations where high build and high compressive strengths are required or in locations where good abrasion resistance is necessary. The mortar is suitable where resistance is required to chlorides and carbon dioxide.


  • High strength and high abrasion resistance
  • Compatibility with concrete compressive strengths >45MPa
  • Capable of achieving high-build; reduces the need for formwork
  • Sustainable product with lower carbon footprint
  • Can be applied by the wet spray process for fast, exceptionally high-build repairs with enhanced strength
  • Extremely low permeability provides maximum protection against carbon dioxide and chlorides
  • Excellent bond to the SSD concrete substrates – no separate primer required in most circumstances
  • Shrinkage compensated
  • Contains no chloride admixtures


    Ideal for:

  • Designed for locations where high build and high compressive strengths are required or in locations where good abrasion resistance is necessary
  • Vertical and overhead repair work


    Surface Preparation:

    Saw cut or cut back the extremities of the repair locations to a depth of at least 5 mm to avoid feather-edging and to provide a square edge. Break out the complete repair area to a minimum depth of 5 mm up to the sawn. Clean the surface and remove any dust, unsound or contaminated material, plaster, oil, paint, grease, corrosion deposits or algae. Where breaking out is not required, roughen the surface and remove any laitance by light scabbling or grit-blasting. Expose fully any corroded steel and clean to a bright condition. Priming reinforcing steel is necessary. Refer to the manufacturer for further information.

    The concrete substrate should be saturated surface dry immediately before the application of the Renderoc HB70. Any residual surface water removed prior to applying Renderoc Renderoc HB70. For improved build thicknesses apply one coat of Nitobond HAR with the Renderoc HB70 applied whilst the primer is still tacky. For further guidance refer to the manufacturer's Technical Data Sheet.


    Care should be taken to ensure that Renderoc HB70 is thoroughly mixed. A forced-action mixer is essential. Free-fall mixers must not be used. For normal applications, place 2.8 - 3 litres of drinking quality water into the mixer and mix the powder into the water until fully homogeneous.


    Exposed steel reinforcing bars should be firmly secured. Apply the mixed Renderoc HB70 to the prepared substrate by gloved hand or trowel. First, work a thin layer of the mortar into the primer or presoaked substrate and then build the mortar on to this layer. Thoroughly compact the mortar on to the primed substrate and around the exposed reinforcement. Renderoc HB70 can be applied in sections up to 100 mm thickness in vertical locations and up to 80 mm thickness in overhead locations in a single application and without the use of formwork. Thicker sections should be built up in layers but are sometimes possible in a single application.

    The minimum applied thickness of Renderoc HB70 is 5 mm. Additional build-up can be achieved by the application of multiple layers.

    Renderoc HB70 can be quickly and efficiently applied by wet spraying in circumstances where large areas of repair are required. Refer to the manufacturer for guidance.

    Clean Up:

    Remove from tools, equipment and mixers with clean water immediately after use. Cured material can only be removed mechanically.


    Shelf life of 24 months from date of manufacture if kept in a dry, cool place.