Newton 403 HydroBond is a very high-performance composite sheet membrane that features a locking fleece to one side and a polymer hydrophilic coating to the other. When placed below the new raft or against permanent or temporary timber wall formwork, the fibres of the fleece inner core are encapsulated into the concrete, forming a close and intimate bond. The membrane becomes fully-engaged into the concrete to prevent water tracking and is suitable for all below-ground and earth-retained structures, ranging from domestic basements to the largest civil engineering projects. The hydrophilic coating expands when in contact with water and seals small holes that may be accidentally formed during fixing of the reinforcing steel or the compaction of the concrete.