The Safeguard Waterproofing System (SWS) - is a multi-coat waterproofing system that is both durable and versatile. The main coating material, SWS Slurry, is a cement-based,
plastic modified powder which is mixed with water and applied to the substrate by brush, spray or trowel. It sets to form a bond with the masonry substrate, creating an impervoius barrier to the movement of water.
Excellent adhesion is ensured by the addition of a specially formulated additive called Bondaid Plus. This also improves the slurry coat's flexibility and strength, as well as making it easier to apply. It is, of course, vital to prepare the substrate first, the application of SWS Salt Neutralisers being an important part of the process. These prevent migration of damaging chlorides, nitrates and sulphates into the coating. Note: where the substrate is of poor quality or there are high levels of salt contamination, consideration should be given to the use of the CDM membrane system.
Before slurry coats are laid down, it may be necessary to relieve water pressure, and this can be done by inserting weep tubes into the substrate. Later these would be filled with SWS Rapid Setting Plug, which jointly expands slightly as it sets. For stress points such as floor/wall junctions, which represent potential weak spots, there is SWS Fillet Seal, a cement-based material that is rapid curing and non-shrink.
SWS systems are able to bridge hairline cracks and can be applied to either the positive or negative side of the substrate. They comprise materials that are non-toxic, non-corrosive and resistant to UV light.
The SWS system is a very popular method of waterproofing cellars and basements. However, it is also often used in less demanding situations, such as preventing damp through soil-retaining walls. In these situatons, the fillet seal, shown on the diagram, can usually be omitted.
The SWS system is also used for waterproofing reservoirs.