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High performance dimensionally stable render carrier board

RCM Renderflex is a high-performance cellulose fibre cement building board, offering excellent strength, weathering and stability properties when used in conjunction with polymer renders.

Renderflex has been specially formulated to achieve a strong key between polymer basecoats and top coats. The unique board structure offers a high tensile strength (ILB) essential for long term durability, whilst being developed to minimise board movement reducing any stress being applied to the render system.


  • Fire rated to EN 13501-1 class A2-s1, d0
  • High dimensional stability
  • Excellent weathering properties prior to render application
  • High impact resistance
  • Maintains minimum board movement
  • Reduced stress on rendered finish
  • Integrates with other RCM products

Standard board sizes

2400 x 1200mm (6mm, 9mm and 12mm)


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RCM Renderflex can be drilled, screwed and nailed with conventional hand tools.

For cutting the product in any volume, we recommend the use of an RCM poly crystalline diamond Dart Blade to avoid excessive wear on other blades. Alternatively, RCM offer a complete fabrication service, please contact our technical department for details.

Key applications

  • Render carrier board
  • For use with polymer renders
  • Internal and external applications
  • Fascia’s and soffit liner

Suitable for the following construction types

  • Lightweight Steel Frame
  • Timber Frame
  • Modular / Offsite

Technical Data

  • 1380 kg/m3
  • 17 N/mm2
  • 9210 N/mm2
  • 0.12 W/mk
  • 8%
  • BS EN 13501-1 Class A2 Limited Combustability
  • Highly Resistant
  • Front Face - Smooth
  • Back Face - Textured
  • 30 years
  • 2400 x 1200mm
  • 6 9 12
  • 8.3 12.4 16.6
    • Length
    • Width
    • Thickness
    • Fire Reaction Tests
      BS EN 13501-1 Class A2 Limited combustibility
    • BS EN ISO 1716:2010
    • BS EN ISO 1182:2010
    • BS EN 13823:2002
    • BS 476 Parts 6 & 7
    • Physical Properties
      BS EN ISO 12467:2012
    • Steel Frame
      4.8mm x 38mm Wing tip self drilling fixing
    • Timber Frame
      4.2mm x 42mm Climaseal self drilling fixing


What applications can RCM Renderflex be used in?

  • RCM Renderflex is used as a Render carrier board for most polymer modified thin coat render systems.
  • RCM Renderflex can be used as an exterior brick and stone slip carrier board.

Which way round should RCM Renderflex be fitted?

  • RCM Renderflex has one smooth face and one textured face, the smooth face should be fixed outermost.

What is the fire rating of RCM Renderflex?

  • RCM Renderflex has a rating of A2 to EN13501-1 this is a reaction to fire classification and should not be confused with fire resistance.

Can RCM Renderflex be used as a permanently exposed external board?

  • No, RCM Renderflex cannot be left permanently exposed.

What are the fixing edge distance and maximum fixing centres for RCM Renderflex?

  • RCM Renderflex edge distance is 12mm except at the board corners where fixings should be moved up or down to achieve 50mm. Fixings should be fixed using a maximum 600mm x 300mm grid pattern.

How many fixings are required for RCM Renderflex?

  • 27 No. fixings per 2400mm x 1200mm sheet when fixed in a vertical orientation.
  • 25 No. fixings per 2400mm x 1200mm sheet when fixed in a horizontal orientation.

What type of fixings should be used?

What blade is suitable for cutting RCM Renderflex?

  • RCM can supply Poly Crystalline Diamond (PCD) blades suitable for cutting RCM Renderflex in a range of diameter and bore sizes, please contact RCM Technical department for further information.



Case Studies

02 . 4
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