Cement tiles are hand-made using the same basic process that was invented in the late 19th century. Sealers didn't emerge on the market until the 1960s and weren't commonly used until a decade later. Before sealers, cement tiles were protected from staining with an application of kerosene and paste wax.
Cement tile manufacturers today recommend a high quality penetrating stone and tile sealer for any installation. However, we have had successful installations without sealers where staining or liquid absorption was not a concern. Furthermore, with the right sealer, cement tile can be installed in pools as a decorative sideboard.
Because cement (or concrete) tiles are porous like natural stone it's generally a good idea to seal them so they are more resistant to staining. A sealer is a liquid applied to cement tiles (and porous natural stones) to help prevent staining from water and oils. In effect, a sealer reduces the natural absorbency of a stone or concrete material. There are two general classes of sealers based on how they work to reduce staining.
1. Penetrating Sealers or Impregnating Sealers (or porosity sealants) coat the cement particles in the tile making it less likely they will retain stains. Impregnating sealers are also classified by the primary carrier or base that is used to make them. There can be either:
a. Solvent Based - Solvent based sealers are absorbed deeper into the material surface and have a strong odor. Furthermore, they are more difficult to apply. Solvent carried impregnators are excellent water repellents.
b. Water Based - A water based sealer doesn't absorb as deep as a solvent based sealer. But this is actually better for most applications because the sealer is sitting just beneath the surface of the cement tile stopping liquids and absorption.
2. Topical Sealers create a barrier on the surface of the tile so that stains do not reach the cement. Topical sealers have different finishes that include shiny, satin and matte. Often matte topical sealers are produced by adding a chemical that cuts the shine, but also weakens the sealer. Topical sealers are not generally recommended for exterior applications as radiant energy from the sun deteriorates them quickly.
A topical sealer sits on top of the surface while an impregnating type sealer sits below the surface or impregnates it. Most topical sealers are not for use on stone. But, you might want to use a topical sealer in addition to a penetrating sealer on cement tile for extra protection against stains or to achieve a slightly different finish. However, always test your sealer and the process on a sample before proceeding to the final installation.
In general, plan on sealing your cement tile installation with a "high quality" water-based penetrating stone and tile sealer. Sealers are not created equal and you get what you pay for. Most "high quality" stone and tile sealers will cost between US $100 to $150 per gallon.
Installing cement tiles is a straight-forward process, but the devil is in the details. Start with our guidelines on the Installation, Maintenance, and Care of Cement Tile.
We'll be discussing cement tile installation details including more about sealers in the coming months. Have a question about cement tile installation that you'd like answered? Let us know and post a comment?