Do pavers need to be sealed at all?

The construction guide for interlocking concrete pavements, ICPI and CMHA's Tech Spec 2 (PAV-TEC-002-22, revised 2022), deals with the question in one short sentence: “Optional sealers or joint sand stabilizers may be applied.”

A Florida paver maker says the same thing without the hedge. Tremron answers its own sealing question with “It is not necessary to seal the pavers,” and then adds what sealing does do: it retards fading of the pavers' color and provides a measure of protection from some stains.

Optional does not mean pointless, and it does not mean required. It hands the owner a decision: whether the reasons a sealer exists matter enough on this particular driveway, walkway or patio. The rest of this answer sets out those reasons in the words of the documents that give them.

One word trap is worth clearing first. ICPI Tech Spec 5 also uses “generally optional,” but that line is about joint sand stabilization, a separate treatment for the sand between the pavers, and not about sealing the paver surface.

ICPI Tech Spec 5 opens its account of sealers plainly: “Sealers are used for visual and functional reasons.” The list behind that sentence is short.

• Less intrusion: “Sealers reduce the intrusion of water, stains, oils and dirt into the paver surfaces.”
• Color: “most sealers change the appearance of the paver surface by darkening it and enhancing the surface color.”
• Stain-prone places: sealers can protect pavers from stain penetration, and ICPI names driveways and other areas subject to stains among the places they are useful.

Note ICPI's verb. A sealer reduces intrusion; it does not stop it. The darker color is part of the look an owner is choosing, and the finish depends on the family of sealer: a film-forming sealer gives the glossy wet look and a penetrating one a flat natural look, both compared under the two sealer families and the finish each gives.

The makers put the color argument more strongly than ICPI's sealer list does. Tremron, writing about its own pavers, says “Over time all pavers will begin to fade if left unsealed.”

Techniseal's FAQ on its concrete paver sealers lists reducing “the rate of color fade” among what its own products do. ICPI, writing about joint stabilizers that cure on the surface, groups them with sealers on the same point: “Like sealers, cured liquid stabilizers that remain on the surface of the pavers enhance their color, inhibit fading, and protect against staining.”

The fading verbs in those lines are slowing verbs: retard, reduce, inhibit. None of them says a sealer keeps color from changing. Whether a darker paver color changes the calculation is its own question, answered under whether dark pavers need sealing.

An owner who decides a sealer is worth it meets one step ICPI puts before any sealer. Tech Spec 5 says: “The sealer manufacturer or supplier should be consulted prior to using any sealer to verify that their product will perform in the environment planned for its use.”

That sentence puts the performance question where the product knowledge is. A general rule cannot say how one sealer behaves on one surface in one climate; the maker's label and data sheet can. The sequence a sealer then goes through, from the clean to the cure, is set out under how paver sealing works.

If an installer has already said no sealer is needed, that advice sits comfortably beside these documents, and the two are reconciled under what to make of an installer who says not to seal.

Tech Spec 2, Tech Spec 5, Tremron and Techniseal all speak here for concrete pavers. Clay brick and natural stone have their own documents, and those documents do not say the same things.

The Brick Industry Association's Technical Note 6A on colorless coatings, dated August 2008 and scoped in its abstract to above-grade brick masonry, says “Clay brick masonry has physical and chemical properties that are different from stone, concrete or concrete masonry,” and that its recommendations apply only to clay brick masonry. What that note says about clay paver pavements is under whether brick pavers can be sealed, and the stone institute's position on travertine is under whether outdoor travertine should be sealed.