A waterstop is a component that can be used to waterproof a concrete structure. The joints that exist where sections of concrete meet can present an opportunity for water to leak, so a number of methods have been developed to deal with this issue. Two two main types of waterstops are hydrophilic and hydrophobic, which are materials that either attract or repel water. The type of waterstop used in any given application depends on factors such as the type of structure and whether any initial leaking will be permissible. Some materials commonly used to construct waterstops include plastics such as polyvinyl chloride (PVC), metals such as copper or steel, and various natural or synthetic rubbers.
Most concrete is fairly waterproof, so it is often used in structures that need to withstand hydrostatic pressure. The weak point in any concrete structure is the joints where sections are connected, so this is where waterstops are required. A waterstop typically consists of some type of material that is placed between sections of concrete to effectively seal them together. Hydrophobic waterstops are designed to prevent water from entering the joints, while hydrophilic materials actually attract water, swell up, and tightly plug the joint. Each of these methods of plugging concrete joints are well suited to different applications.
