SB-4000 Water Repellent & Salt Blocker is a water-based silane/siloxane invisible penetrating sealer. It can be used indoors and outdoors, on old and new, horizontal or vertical surfaces. SB-4000 can be applied immediately after most surface installations, as it is breathable and will not trap naturally occurring moisture or efflorescence. On new concrete, SB-4000 should be applied once concrete is fully cured (30 days after installation). SB-4000 protects surfaces from water penetration and salt damage from the use of de-icers or exposure to salt air. Due to its superior water repellency, SB-4000 helps to reduce biological growth such as mold, moss and algae. It is non-hazardous and VOC/EPA compliant. SB-4000 has the consistency of water, is milky white when applied and dries transparent on most surfaces. Some surfaces may darken slightly. Cured sealer is freeze resistant to -60°F (-51°C) and is stable up to a temperature of 180°F (82°C).