No, the WAVE method causes no damage to the subsoil. The WAVE machine operates at a low pressure of 2.5 bar (comparable to the water pressure from a kitchen tap) and does not use high-pressure injection. The low pressure means that the sand in the joints simply remains in place. This is a major advantage by comparison with other weed killing methods, which use brushes for instance. Working with WAVE means less damage and so lower maintenance costs for these paved surfaces.