How do you choose a masonry water repellent when there are many different types available. Siloxanes, Silanes, Silane Siloxane blends, Silicones, Acrylics, etc.
Siloxanes are available in a water based solution and what is important is the solids content of an individual formula. Siloxanes generally work best when the percentage of solids is 10% and up to 40%. Once the water evaporates, you want the active solids to react within the masonry to form a water repellent polymer.
Siloxanes/Silane blends are available in water based solution. The active solids should also be a minimum of 10% and up to 40%. This blend works best when you have both a dense surface and very porous surface in the same area to be sealed.
Silanes have a small molecule are are available in 20% solids and 40% solids in a VOC compliant solvent. Great for cold weather application and work best on dense masonry surfaces. Solvent based sealers also tend to evaporate at a faster than water based and are ideal for tight areas where over spray is a concern.
Silanes 100% solids contain high solids and have little or no solvents. They are VOC compliant and work best on very porous surfaces
Acrylics come in both water based and voc compliant solvent based formulas. Typically the solids content on acrylic sealers varies greatly depending on the end result desired. 10% and up to 30% are common. Some formulas leave a sheen, some are flat, and some formulas darken the surface. Acrylics allow the surface to breathe but are not as breathable as Siloxanes or Silanes. Best when used on very porous concrete block, split faced block , and split ribbed block.