Specifiers Guide

Specifiers Guide

Heave Stopper Specifiers Guide
Heave Stopper is straight forward to specify. All Heave Stopper boards will satisfy the requirements for beams, slabs and concrete thickness up to 1 metre.

Simply select the correct thickness to accommodate the heave potential of the ground based on site investigation and soil analysis results.
Further guidance on predicted ground movements in shrinkable soils is given in the NHBC Standards 2018, Chapter 4.2.
The thickness of Heave Stopper should be equal to the required void plus 10mm. See table below. 

Heave Stopper - Standard

Product Code Soil Analysis Result (Plasticity Index) HHBC Category (Shrinkage Potential) Predicted Ground Movement Potential or BRE/NHBC Requirements (Void) Heave Stopper Thickness Colour Code
HS060 10 - 20 Low 50mm 60mm Red
HS110 20 - 40 Medium 100mm 110mm Green
HS160 40 - 60 High 150mm 160mm White
Heave Stopper has a compressive strength of 120kN/m2.
When dry, it is designed to have sufficient strength to support wet concrete and steel up to 1 metre thick.
The board’s mechanical properties have been independently tested at the BRE Innovation Park. Tests show that the initial saturation procedure leaves just 10mm of material in the void zone.
Ultimately a 100% clear void is created which is in excess of the specified requirements and with zero kN/m2 of transmitted force.
Heave Stopper can also be used horizontally and vertically to create a void to protect
structures from vibration.

Heave Stopper - Board Size

Heave Stopper is supplied in boards 2400mm x 1200mm as standard.

Boards can be cut to your required size prior to delivery, helping save time and costs on site.

Heave Stopper - Protect

Heave Stopper is also available packaged in a Water Tight 500g Polythene bag to protect the board against natural elements. 

Please note that the boards will need to be removed from the Polythene bags prior to the concrete being poured. 

Heave Stopper - Void Pipes

Make provision to introduce water in to the Heave Stopper boards by way of the Void Pipe. A Void Pipe is required every 25m2 or for every isolated area of Heave Stopper. Tie the Void Pipe to adjacent reinforcement to hold upright during the concrete pour.

Available in 450mm and 600mm lengths.


The maximum NHBC void from just 160mm board

Heave Stopper is the ultimate reduced dig solution for void creation.

  • The slimmest method of void creation.
  • A perfect solution for contaminated land and brownfield sites.
  • Ideal for sites with restricted access.
  • The dense cell structure of the board creates a solid working surface that does not need hardboard or concrete binding.
  • Lowest possible forces transmitted to the structure.
  • BBA certified
  • Complies with NHBC standards chapter 4.2

Heave Stopper without water

Heave Stopper after water is introduced showing ground heave

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