The Permapro SP polymeric sand constitute a unique mixture of polymer binders and calibrated sand. In contact with water, it becomes very firm and literally locks the concrete paving stones between them. This very strong bond is then ideal to hold paving stones in place, whether the surface is horizontal or not. Made for sloping areas around pools ans all types of driveways and walkways as well as paver joints up to a maximum of 1" (1 cm). 30 kg. Grey.