What Does Lithium Silicate Do to Concrete?

Bisley InternationalFAQs

What Is Lithium Silicate?

Lithium silicate is a compound in which lithium is used as the transporting agent to carry the silicate into its desired application. Used in a variety of applications, including dentistry, and as a bonding agent in materials such as fibreglass, lithium silicate is also used as a concrete hardener and concrete sealant.

How Does Lithium Silicate Work?

Lithium silicate is applied to a polished concrete floor as a liquid, using the lithium base to facilitate application. The silicate needs to penetrate into the concrete to a depth of around 5mm.

Once impregnated into the concrete, the silicate creates a chemical reaction with the calcium hydroxide, a by-product from the mixing of concrete powder with water. This reaction in turn produces calcium silicate, which fills the porosity in the surface of the concrete, thereby sealing and hardening it.

This treatment acts as a concrete densifier, as well as being water repellant. This treatment also makes for smooth concrete floors, and in turn aids floor polishing. Treatment with lithium silicate also makes the concrete stain resistant.

Why Do We Use Lithium Silicate?

There are alternatives, such as potassium silicate and sodium silicate. These both perform in much the same way as lithium silicate and are less expensive. So why should we use lithium?

Here are a few of the advantages of using lithium silicate over sodium or potassium.

  • As a silicate densifier, lithium dries in around 6 hours, as opposed to a full day or more for sodium and potassium.
  • Lithium silicate has a higher flash-point than the other compounds, making it less hazardous to store and transport.
  • The solubility of lithium silicate is far lower than the other either sodium silicate or potassium silicate.
  • Lithium silicates contain less alkalinity, therefore they’re more environmentally friendly.
  • One coat of lithium silicate is all that’s required. The others require two or more coats.
  • Lithium has better bonding properties than either sodium or potassium.
  • Lithium is more reactive and can support a higher density of silicate. The result is less abrasive resistance on the concrete floor.
  • Higher silicate concentration means that less of the compound is used, resulting in less residue to clean up after application. Less clean-up also means less cost of removal.


Lithium silicate is the better compound for the treatment of concrete floors. Its suitability as a concrete densifier, as well as its water-repellant characteristics, outweigh the initial cost.

It’s safer to store and transport. The application time is much quicker than other methods, and its ability to hold silica in higher concentrations means that less of the product is applied.

Considering all of the advantages, lithium silicate is by far the best choice in sealing and hardening treatment for concrete floors.

Xeolith® LS450 Lithium Silicate