Quarry tile adds beauty and value to your home. Perhaps the most well-known type of quarry tile is terra cotta, which is made from red clay. However, quarry tile is available in a wide range of colours and designs to suit any decorating theme. It's important to apply sealant to quarry tile. The tiles are porous and will absorb stains along with water if left unprotected. It's not hard to seal quarry tile. You should use a sealing compound formulated for unglazed tile. Avoid common substitutes like linseed oil or floor wax. These do not properly seal the tile and may result in discolouration because the tiles will trap dirt.
Test the quarry tile to see if it needs to be sealed. With newly-laid tile this isn't needed, since you know sealing is required. Existing tile should be re-sealed periodically (about every two years). Place an ounce or so of water on a tile. Allow it to set for 5 or 10 minutes and then dry the tile. Wait about 2-3 minutes. If the tile is still darkened from water absorption, it's time to re-seal.
Clean the tile thoroughly using grout and tile cleaner. Manufacturer's instructions vary, but in general you should spread the cleaner on and allow it to set for a half hour or so, and then wipe the cleaner off the tile. Allow the tile to dry completely before applying sealant. To be sure it's completely dry, leave the tile overnight.
Use a good paintbrush to apply the first coat of sealant. Spread a layer of sealant over the tile area and let it soak in for about 5 minutes. Use a rag to wipe excess off the tile. Wait at least 30 minutes and then apply a second coat the same way. Again, wait a few minutes, and then wipe off the excess. Allow the tile to dry for 2-3 hours before resuming normal use of the area.