Mystery of Sealers

There are many sealers on the market today for tile and natural stone application. It can be a confusing task to make the right selection. Fortunately, all of these products fall into two major categories: coatings and impregnators (penetrating sealers).

Understanding Coatings and Impregnators

Coatings are sealers that place a sacrificial coating on the surface to act as a barrier to prevent water, oil and dirt from entering the pores. Coatings tend to be divided into two types: strippable and permanent.

Strippable coatings are designed to be easily removed from the surface. There are many of these coatings on the market for use on many different types of material. Be sure the one you select is appropriate.

Permanent coatings are difficult to remove. They are of materials such as polyurethane and epoxies. These are not recommended for use on stone or tile.

Impregnators or penetrating sealers are designed to penetrate below the surface. They deposit solid particles in the pores or coat the individual minerals below the surface so that water, oil and dirt are restricted from entering the stone.

Impregnators can also be classified into two types: hydrophobic (water repelling) and oleophobic (oil repellent). Hydrophobic impregnators are designed to repel only water and water-based chemicals such as fruit drinks, coffee, tea and soda. Oleophobic impregnators are designed to repel water and oil-based liquids such as cooking oil, grease and body oils.

The maintenance procedures currently being used on the floor should be considered in selecting a coating. A marble floor that is mopped daily may be exposed to harsh chemicals. If floor maintenance is neglected, the high polish will appear worn from ground-in dirt and grit. In the case of poor maintenance, the floor will appear dull no matter how well the floor is protected with a coating.

Coating or Impregnator?

The decision to use a coating or impregnator can be a challenge. Coatings are generally economical, easy to apply, provide a sacrificial coating on the stone, can be applied below grade, provide varying degrees of luster. On the other hand, they will easily scratch, mar, scuff and generally show traffic patterns. Coatings can build up on the surface requiring frequent removal and reapplication to keep the floor looking like new.

Impregnators generally will not change the appearance and do not require frequent application and are not affected by ultraviolet (UV) light. Impregnators are more costly. Those that are solvent based can produce noxious and flammable vapors during application and can be harmful to the environment, if not handled according to manufacturer specifications.

These guidelines should help you determine the proper product for the protection your floor requires. Be sure to consider all the factors above prior to making your decision.