How to Seal Mexican Clay Tile

Mexican clay tile is usually handmade and fired at low temperatures. Available in either glazed or unglazed and sealed or unsealed, this tile is nonvitreous, which means it absorbs water, especially during the winter's freeze/thaw cycle. This makes it less than ideal for exterior installations, except in the dry, desert Southwest. There are different types of sealers, including surface sealers, which penetrate the tile slightly but have a glossy sheen, and penetrating satin-finish sealers, which soak deeper into the tile but don't protect as well as the surface varieties.

Things You'll Need

• Sponge
• Sealant
• Foam brush
• Roller

Instructions

Uninstalled Tile

1. Soak the individual tiles in a bucket of water with a drop or two of dishwashing soap before installation. This keeps the tile from absorbing the water from the mortar or thinset cement, which is the adhesive in which the tile is laid, when it is installed. Although the tile may turn white, this disappears once the tile is dry. Remove any standing water and let the tiles air-dry for at least 30 minutes.

2. Install the tile on the mortar or thinset. Apply a thin coat of impregnator sealant, which permeates the pores of the tile and seals from the inside out, to the tiles with a foam brush, roller or low-pressure sprayer before the grout is installed. Check with the tile manufacturer for the proper sealant.

3. Allow the first coat of sealant to dry for two hours. Apply a second coat. Allow it to dry for two hours. Install grout. Apply another coat of sealant after the grout is installed, sealing both the tile and the grout. Avoid walking on a clay tile floor for 24 hours after a sealant is applied.

Installed Tile

1. Clean the tiles with a small amount of laundry detergent and a damp sponge, or a clean mop for a floor, to remove dust, dirt and grime. Remove any standing water from the tiles and allow them to air-dry for at least 30 minutes before applying sealant.

2. Apply a thin coat of sealant with a roller, foam brush or low-pressure sprayer, for large areas. Allow the first coat to dry for two hours. Apply a second thin coat of sealant.

3. Re-apply sealant once a year to protect tile and keep it looking new. Avoid using solvents or harsh chemicals between sealant applications. Keep clay tile clean with water and a small amount of soap.

Tips & Warnings

• Even if the tile says it is glazed, it still must be sealed. Check with the tile manufacturer for sealant recommendations to make sure the tile lasts.

References

• Working With Tile; Tom and Lane Meehan; 2005
• Setting Tile; Michael Byrne; 1995
• Complete Tile; Sunset; 2002