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


For concrete pours over 1 meter a special grade of Heave Stopper is available.


Heave Stopper is the slimmest method of void formation available. Using Heave Stopper results in less excavation, less muck away & less landfill. 


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 2013, Chapter 4.2


The thickness of Heave Stopper should be equal to the required void plus 10mm.






Predicted Ground

Movement potential or

BRE/NHBC requirement 

Heave Stopper





Void Thickness
10 - 20 Low 50mm 60mm
20 -40 Medium 75mm 85mm
20 - 40 Medium 100mm 110mm
40 -60 High 150mm 160mm

Heave Stopper has a compressive strength of 30kn/m2.


When dry, it is designed to have sufficient strength to support wet concrete and steel up to 1 meter thick without deflection or creep compression. Once the core is wetted it will yield to the pressure of ground movement with less than 3kn/m2 of transmitted force to the structure above.


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 is supplied in boards 2400mm long by 1200mm wide, by the specified thickness


BBA Agrement Certificate for Heave Stopper
Heave Stopper bba.pdf
Adobe Acrobat document [1.7 MB]
Ground Movement & Clay Heave protection solutions.
Heave Stopper is a robust, easy to cut void former used to protect concrete foundations from clay heave.
Using Heave Stopper protects your buildings against the forces of ground movement, and unlike other solutions, Heave Stopper creates a complete void beneath the foundation to offer maximum protection from ground movement.
Whiterock Heave Stopper brochure.pdf
Adobe Acrobat document [1.3 MB]


Using HEAVE STOPPER protects your buildings

against the forces of ground movement.


If you would like to discuss your particular project with us please make contact here >