There are two basic types of natural stone sealers to choose from: topical and penetrating. Choosing the best natural stone sealer will depend largely on the type of stone you have and its usage. Topical sealers are typically used to polish and protect the surface of porous stones such as limestone and slate. Penetrating sealers usually work best for less porous stones such as granite and marble. Both types of sealers may contain special additives to alter the stone’s color or appearance.
Determining the type of stone you have is the first step in choosing the best natural sealer. Veining patterns in the stone typically indicate some type of marble. Fossil formations are usually found in softer stones such as limestone. Rough hard stones with a crystalline appearance are most likely granite. Slate stones typically have a dusty, crumbly surface.
A topical natural stone sealer is usually composed of acrylic or urethane and helps to create a protective barrier against water and oil. Applying this type of sealer typically produces a polished appearance on the stone surface. Topical sealers can become quite slippery when the stone is wet and a special non-slip additive may be needed for bathroom and kitchen applications. The shiny surface produced by topical sealers can be buffed to a high gloss if desired.
Topical sealers also have a tendency to darken the surface of the stone and generally alter its natural finish. The protective coating often shows scuff marks and scratches from foot traffic as well. The finish produced by a topical sealer tends to wear down quickly in high traffic areas and frequent recoating may be necessary. This type of natural stone sealer usually requires more maintenance than penetrating sealers and will likely need to be reapplied every six months.
A penetrating natural stone sealer works beneath the surface to protect it from oil and water damage. Penetrating sealers usually do not affect the appearance of stones in any way. This type of sealer does not protect the surface of the stone from scratches and abrasions caused by foot traffic. Penetrating sealers will not wear off the surface of the stone like topical sealers and generally require less frequent maintenance. A special cleaner may be needed when this type of sealer is used.
The kind of natural stone sealer you choose will depend largely on the finish you desire. The glossy finish produced by a topical sealer usually offers the best overall protection for soft, porous stones in high traffic areas. A penetrating sealer generally offers the best type of protection for hard, dense stones such as marble and granite. Both penetrating and topical sealers are available with a special color enhancing agent to deepen the natural color of the stone.