So what exactly is a silicate and why does every concrete sealer company offer and sell silicates? Silicates have been around for many years and sodium silicates have been used in concrete applications for over 100 years. As far as a concrete application silicates are used primarily as densifiers to harden and strengthen concrete. They are best applied to floors before they are polished since they give concrete the kind of shine you find on a floor of a big box hardware store.

Sodium silicates are the oldest of the silicate family and their claim to fame is a chemical reaction that takes place when the silicate comes into contact with Portland cement through a process called hydration. Calcium Silicate Hydrate is produced creating a stronger, denser substrate also reducing the porosity of the concrete slab. Potassium and Lithium silicates are newer to the market place, essentially working the same chemical reaction with a potassium or lithium carrier instead of a sodium one. Lithium silicates are usually more expensive that sodium silicates because of the smaller size of the lithium ions.

Our Take: Silicates are sold pre-diluted and concentrated and it is really up to the end user to decide if they want to dilute the material themselves to save on shipping or if they want to buy a diluted version to save on the hassle. VSeal and Hydrablock are good diluted varieties while Sila-Tek 3500 is sold concentrated and will give you the most bang for your buck.