BEWI Claymaster (Clay Heave Protection) is a product designed to protect against clay heave.

Shrinkable clays are soils containing a large proportion of mineral particles of less than 0.002mm in diameter.

This produces an extremely cohesive soil type when wet, but shrinks to a crumbly, crazed structure when dry. The expansion and contraction process during wet and dry periods is known as ‘clay heave’. This can cause severe problems with foundations.

Claymaster works by surrounding the pile cap with a layer of low density, compressible, expanded polystyrene, reducing pressure on the ground beams as the surrounding clay expands and contracts.

For further technical information refer to this link.