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Wednesday, October 07, 2015


I have about 10,000 square feet of unglazed ceramic tile that is in a busy church. The tile and grout is in poor shape and has never been sealed. First I will be cleaning it to get in good shape and then sealing it. How many coats should be used. What brand name of sealer should be used. How often will this need to be re-sealed.


There are two basic types of sealer. One is a penetrating/impregnator seal that sinks into the surface of the flooring and grout. The other type of sealer is a topical/sacrificial coating in that it stays on the surface to protect the floor against wear and moisture/stain penetration.
If you just want protection against staining and moisture the penetrating seal will do the job. If you want a different surface appearance, (more shine) use a topical sealer. In general the cleaning and tile industry does not recommend that topical sealers or coatings be applied to clay tile or grout as they increase maintenance costs, wear off the smooth areas, don't let the floor breathe and are difficult to remove from the grout. The preferred product is a penetrating/impregnating sealer that does not change the appearance of the surface of the tile, but protects it from moisture and staining.
Ceramic tile is very durable and surface finishes are not in most cases needed to protect against wear of the tile itself. Floor finish manufacturer websites will provide a wealth of information on application techniques and what is available. Clay/ceramic tile manufacturer sites provide information on maintenance procedures for clay tiles. Topical seals are on the surface and will wear and scratch. If you do apply a topical sealer, scrub and recoat when the wear is obvious.
There are many companies that make sealers, finishes and cleaners for grout, ceramic, porcelain and stone tile. Two that you may want to check out in your research include:
Lynn E. Krafft, ICQN/ATEX Associate Editor