What is a load-bearing layer (also known as a subbase)?

The term load-bearing layer originates from road construction and refers to all the materials and layers installed beneath the wearing surface of a road, path, or tiled area. They create a level, supportive, and stable foundation on which the surface covering is laid. This robust load-bearing layer ensures the durability and stability of the entire structure.

Generally, a distinction is made between bound and unbound layers. Bound layers are installed as a continuous element using materials such as concrete, asphalt, slabs, or tiles, while unbound layers consist of loosely laid components like in-situ or dumped soil, sand, gravel, or crushed stone – including concrete gravel mixed with stone chippings.

WARCO enhances this conventional concept by dividing load-bearing layers into three groups: unbound, grid-based, and bound layers. In grid-based layers, products like plastic honeycomb grids or metal grid plates are used. Bound layers also include concrete pavers, composite pavers, roofing felt, foils, bitumen membranes, natural stone slabs, exposed concrete, composite panels, printed panels, multiplex boards, sheet metal, double standing seam metal, and wood floors such as parquet, laminate, or WPC.