Silane/siloxane sealers are fairly popular amongs homeowners simply because they are easy to use, work on a variety of concrete substrates (especially porous concrete such as cinderblock), and last for anywhere from 3-10 years depending on the sealer and the application. Silane siloxanes penetrate into the concrete and chemically react to form a breathable, hydrophobic barrier within the pores. Siloxane siloxane sealers will cause water and other liquids to bead off the surface and they will reduce surface water absorption. By reducing the absorption of water on the surface, they will prevent a variety of issues including freeze thaw and salt damage, spalling, mold and mildew.
There are two types of silane/siloxane sealers, water based and solvent based. Water based silane/siloxanes have lower VOCs but solvent based silane/siloxanes have been proven to bond better, last longer, and perform better in areas where climates are known to change.
Another factor to consider when purchasing is a silane siloxane is the % solids. Solvent based: Most stores will offer a 2-8% solids solution while many distributors will offer a 20-40% solution. The more solids present in a solution, the more protection the sealer will offer within the pores and on the surface. Water based: Water based solutions tend to be lower solids. High solids for water based tends to be 7.5-10.5%.
Foundation Armor: Armor SX5000, low VOC solvent based 40% solids
Foundation Armor: Armor SX5000 WB, low VOC water based 10.5% solids