In the market of concrete sealers, there are a number of different options available to you. There are offerings such as surface-level sealers, such as acrylic sealers, epoxies, or polyaspartics and urethanes. Then, there are the penetrating variety of sealer, such as silicates, whose carriers can range from sodium to lithium. While it may be confusing to determine the difference between a silicate and a silane/siloxane, for example, the differences are not all that esoteric.
For instance, we shall consider a silicate versus a silane/siloxane. A silicate is a penetrating sealer made up of small particles of sealant. These small silicate particles are suspended in a sodium or lithium carrier that helps transport the particles past the surface pores of the concrete. The water or solvent which the silicate sealer is based in will simply allow the particles of silicate and sodium/lithium to be spread on the surface – from there, the water will evaporate and the solvent will become part of the concrete.
Once within the concrete, the silicate particles will pass through the vast network of miniscule hairline cracks and microscopic pores natural to every piece of concrete. Part of what makes concrete such a strong material is the build-up of calcium silicate hydrate. Silicate sealers react chemically with minerals present within the concrete to create more CSH, which makes the concrete stronger while simultaneously blocking out the passage of water, salts, and gases through the concrete.
Silane/siloxanes, while also a comprehensive type of concrete sealer, work a little differently. While the silane particles penetrate within the concrete, they do not react chemically to densify the concrete. Instead, the silane and siloxane particles will work in concert to create a hydrophobic barrier that will block out water and moisture. The larger particles of siloxane will remain on the surface of the concrete to provide the brunt of this barrier, while the silane particles will complement the barrier, reinforcing it to make it stronger.
As the silane/siloxane sealers feature larger particles, they are better suited for such concrete surfaces as cinderblocks, concrete blocks, and bricks – the more porous materials to which you cannot apply silicates. Both sealers are excellent choices for projects that require their particular strengths, but just make sure to do the requisite research to determine which your project needs.
Our Take: Silane/siloxane sealers readily available are Siloxa-Tek 8500 and Okon S40 while a silicate densifier that has stood the test of time is The Ashford Formula.