Ground heave, or sometimes known as clay heave, is the upward movement of the ground when moisture in the earth increases. When wet, ground clay will expand upwards causing the soil to rise and effect the upper surface of an area. This can cause serious structural damage to a building’s foundation and structure.
Clayboard is designed to create a technically sound void, solving the ground movement issues when ground heave occurs and preventing structural damage to a building.
What causes ground heave?
There’s a number of causes associated with ground heave, but the most common is tree removal from a development site. When trees are cleared, the root network no longer draws water from the subsoil causing water to accumulate in the ground. This results in the expansion of soil and upward ground movement.
Other causes of ground heave include seasonal weather changes, particularly with the onset of wet weather after a dry summer, a change in the level of the water table, faulty or damaged drains and the excavation of soil relieving pressure on soil layers below.
Effects of ground heave
Where a building has not been designed to accommodate potential ground heave, cracking can occur on the brickwork and around windows. There may also be ‘sticking’ of doors and windows as the frames can be disfigured. In extreme cases of ground heave, floor slabs, paths and patios can lift and crack.
View the video created by Cranfield University, this explains more about the shrink and swell behaviour of clay soils.