There are several factors to consider when choosing the proper paving sealer including the type of pavement to be sealed, the location of that pavement, the ease of applying the sealer, and level of protection of the sealer. Paving sealer comes in two main types that will greatly impact each consideration. Topical sealers, or film formers, are generally the less expensive option and are easier to apply, but they usually require more frequent applications. Penetrating paver sealers typically are more expensive than topical sealers, but they are also longer lasting and offer more protection for your stone surfaces.
Choosing the best paving sealer will largely hinge on what kind of pavement you're sealing. Paving sealer can be applied to a variety of surfaces from natural stone to asphalt to adobe tiles. Most paving sealers work with most any of these types of pavements but you should verify that the pavement material you want to seal works with the type of sealer you intend to use.
Where the pavement to be sealed is located and how it is used should also be considered. Sealers are designed to help protect the surface from stains and daily wear and tear, as well as help maintain the look of the material by helping it resist fading and prohibiting weed and mold growth. Still, some paving sealers are designed to satisfy one ore more of these goals more than others. Finding a highly stain-resistant sealer, for example, may be important if your sealing a highly-trafficked pavement.
How easy a sealer may be applied and how often it will need to be reapplied are two more important consideration when choosing a sealer. While a topical paving sealer offers basic protection, it will typically need to be replaced at most every two to three years. The old film also must be removed before applying the new coat, a process that can damage the stone. If it is not replaced a build-up will occur, leaving the surface with a plastic-coating look.
A penetrating paving sealer, as the name suggests, soaks deeper down into the pavement, where it deposits resins that offer superior protection compared to a topical sealer. These types of sealers, while typically harder to apply, generally protect surfaces longer than topical applications. They generally don't need to be reapplyed for anywhere from three to ten years.