Swellable Water Stopper

The Swellable water stopper, also known as ‘hydrophilic water stops’, are advanced sealing materials used in concrete construction to prevent the ingress of water through joints that experience movement (contraction or expansion). Unlike  the regular and conventional PVC water stoppers that act as a ‘physical’ barrier, swellable water stoppers function by actively expanding in the presence of water, creating a self-sealing effect preventing corrosion or damage taken from it. They are typically made of hydrophilic materials such as modified rubber, bentonite, or polyurethane-based compounds, which are excellent candidates when the requirements are to can absorb water and increase in volume efficiently tightening and sealing the joint.

These water stoppers are extremely effective in structures exposed to continuous or intermittent water contact and movement. When installed in construction or cold joints, their impressive property to swell up ensures that even the smallest cracks, voids, or gaps in the structure are sealed against water leakage and pressure.

One of the main and key advantages of these swellable water stoppers lies in their simplicity of installation. They are usually supplied in “strips”, “cords”, or “profiles”, and can be fixed directly onto the concrete surface using certain adhesives or mechanical fasteners before pouring the next layer of concrete. When the structure is exposed to mild moisture, groundwater or pressure, the material begins to swell—sometimes up to several times of its original volume—forming a tight compression seal within the joint preventing the entrance of water.

Swellable water stoppers are also extremely flexible, allowing them to adapt to slight movements in the structure caused by temperature changes, settlement, or vibrations of the joints. They are extremely resistant to many chemicals and can function surprisingly effectively under varying hydrostatic pressures and conditions. However, to maintain elite performance, they must be protected from premature swelling during the time of construction, usually such is achieved by applying protective coatings or using appropriate covers.

Overall, to make it brief, swellable water stoppers offer a simple, reliable, self-healing, and cost-effective solution for ensuring watertight concrete structures, that have the ability to also allow slight movement, especially in challenging underground and water-retaining structures.