SikaCem 520 Waterproofer is an integral waterproofing chemical. This means that, it is added to the water intended for the concrete or mortar mix so forms an integral part of the concrete or mortar structure right when the mix is completed and ready to be worked with or used. It's composition is such that, as the concrete or mortar dries, it forms a rubberlike texture all through the entire fiber or structure of the concrete or mortar thereby preventing the ingress of water.