The process of making a structural element water repellent is know as hydrophobising. The hydrophobising agent coats the internal surfaces of pores and capillaries. The breathability of the material is maintained as the pores and capillaries are not sealed.

Impregnating a concrete surface reduces the surface porosity and strengthens the surface. The pores and capillaries are partially or completely filled in.

Coatings close pores and capillaries completely and create a thin protective layer on the concrete surface. Coatings have many different uses including non-slip steps, attractive balconies and aesthetically appealing walls.