Penetrating Vs. Surface Sealers
While some sealers seep into porous paver materials, others form a film over the pavers' surface. Sealers that seep are called penetrating sealers; sealers that form a film are called surface or film sealers. Penetrating sealers prevent stains and water absorption in porous materials such as concrete pavers. Surface sealers create a thin layer on the exposed surface of pavers to perform similar functions. Because pavers actually absorb penetrating sealers, penetrating sealers usually increase the pavers' longevity. However, surface sealers usually have the most dramatic effect on pavers' appearance, as they remain on the pavers' surface.
Specialized Vs. General Purpose
While manufacturers offer specialized "paver sealer" compounds, you'll find that many general purpose masonry sealers also are suitable for sealing pavers. Whether you select a specialized sealer or a general purpose sealer, it's crucial to choose one that's formulated for your specific type of pavers. If you're sealing clay brick pavers, your sealer's label should specifically list clay brick as an acceptable application surface. Many general purpose sealers are suitable for all porous masonry materials, including concrete and clay brick. Specialized paver sealers often contain adhesives that bind sand joints between dry-laid pavers; general purpose masonry sealers don't perform the same function.
Sealer Appearance Options
Surface sealers are available in several sheens. The term sheen refers to the sealer's degree of luster: usually matte, semi-gloss or gloss. A sealer's luster usually doesn't affect its durability or longevity, so sheen choice depends on your personal preference. Matte sealers allow pavers to present their natural appearance; glossy sealers make the pavers shine, giving them what's sometimes described as a "wet" look. However, some glossy sealers are more slippery than matte or penetrating sealers. You can increase a glossy sealer's slip resistance by mixing a grit additive with the sealer before application. Alternatively, many sealer manufacturers offer slip-resistant formulations.
Benefits of Sealing
Both penetrating and surface sealers help pavers maintain their original appearance. Sealers prevent pavers from absorbing grease, dirt and moisture. Protection against moisture is particularly important, because water damage eventually causes pavers to chip, split or develop unsightly surface damage. Specialized sealers that bind paver joint materials increase the paved surface's strength, reduce cracks along joints and can prevent pavers from loosening, settling or heaving.