DOWSIL Contractors Weatherproofing Sealant is a medium-modulus, one-part, neutral-cure silicone designed for durable weatherproofing of building joints. CWS provides balanced adhesive strength, high recovery, and long-term flexibility, making it ideal for expansion, control, and perimeter joints in concrete panels, curtain walls, EIFS systems, and tilt-up construction.
Formulated for primerless adhesion to most common nonporous substrates, DOWSIL CWS delivers consistent performance across a wide range of materials including glass, metal, and concrete. It remains easily gunnable from -20°F to 120°F (-29°C to 49°C), ensuring smooth application in all weather conditions.
Once cured, the sealant exhibits excellent resistance to UV radiation, heat, and moisture. It achieves a joint movement capability of ±40%, maintaining elasticity under dynamic stress and environmental exposure. With its low VOC content (35 g/L), it meets ASTM C920, Type S, Grade NS, Class 35 standards and provides a professional finish with long-term durability.
DOWSIL CWS offers flexible design aesthetics while meeting the performance demands of today’s construction professionals. Its easy tooling, minimal maintenance, and proven reliability make it a preferred choice for both new construction and restoration projects.


