
Silane, Siloxane, and Siliconate-based Water Repellents are all formulated and designed to prevent the ingress of water and chlorides by modifying the surface tension of the substrate. They penetrate and chemically react with the substrate changing the surface tension to provide a water-repellent barrier. This barrier protects the aesthetics and the integrity of the treated surface by keeping contaminants such as water, salt, chlorides, and sulfates from penetrating the surface of the treated substrate.
Silanes (alkoxysilanes) are small molecules that require alkaline pH to properly bond to a surface. Because of their small size, they deeply penetrate the material to be sealed offering optimal performance and long-lasting protection.

Siloxanemolecules are similar to alkoxysilane in terms of surface performance and protection, but they are much larger in size and cannot penetrate as deeply as alkoxysilanes. They work well at lower active concentrations and are generally more economical than alkoxysilane water repellents.

Siliconate is the smallest molecule in comparison to alkoxysilane and siloxane and provides the deepest penetration. However, siliconate wears down more rapidly than alkoxysilane and siloxane. Siliconate is an economical water repellent chemistry but must be re-applied more frequently to maintain optimal surface protection.
All three water repellent types provide a flat finish with no gloss or sheen maintaining original surface aesthetics. They all produce a water beading or a water sheeting effect when properly applied. The pores and capillaries of treated substrates are internally lined, but not filled like paint or coating, ensuring the substrate doesn’t trap moisture and the surface remains fully vapor permeable (breathable).
| Silane (alkoxysilane) | Siloxane | Siliconate |
| Small molecule (concentration needed 20-100%) | Large molecule (concentration needed 5-20%) | Smallest molecule (concentration needed 3-10%) |
| Deep penetration | Stays closer to the surface | Deep penetration |
| High pH surface required (for dense surfaces like concrete and masonry) |
Not pH sensitive (for low to high porosity surfaces like brick, concrete, stucco, and stone) |
Not pH sensitive (for brick, concrete, stucco, and stone) |
| No surface darkening | No surface darkening | No surface darkening |
| Long term protection-Good for abrasion and weathering | Long-term protection–Good for abrasion and weathering | Wears away faster than Silane and Siloxane-Economical |
Chemical Products Industries, Inc. offers a complete range of Silane, Siloxane and Siliconate based Water Repellents
For assistance in finding the right surface protection product for your specific needs, please contact our team of industry experts.
Related Products:
SW-244-100 VOC™ Silane Water Repellent
SW-244-40 VOC™ Silane Water Repellent
CP-500W™ Siloxane Water Repellent
CP-1000™ Siliconate Water Repellent