HYDROJOINT SL is a hydrophilic, thermoplastic elastomeric expansive waterstop engineered for sealing concrete construction joints, concrete-steel interfaces, and underground precast elements. Delivered with a swell retardant coating, it expands gradually upon water contact—fresh or salt—and reversibly returns to its original size when dry, ensuring reliable long-term performance. HYDROJOINT SL offers safe, easy installation with nails or PU adhesive, excellent chemical resistance, non-toxicity, and superior flexibility to absorb construction movements. Its high swelling capacity and reversible expansion make it ideal for dynamic environments requiring durable, maintenance-free waterproofing solutions.