Can pavers with efflorescence be sealed?

Three of the four put a condition ahead of the sealer. The fourth is one maker describing one product. What the white deposit is, and why it forms, is defined under efflorescence.

ICPI Tech Spec 5 is plain about the order: "All dirt, oil stains and efflorescence must be removed prior to sealing." Tech Spec 6 places the same step in its sequence, with a sealer following stain removal, efflorescence removal and overall surface cleaning.

The reason is what can happen under a sealer. ICPI lists four conditions, and says the pavers may draw efflorescence to the surface, or the sealer may whiten, under any one of them. Two bear directly on efflorescence that is still coming: a source of it under the pavers, in the sand, base or soil, moving up through the joints or the units, and a sealer that is not breathable, one that does not let moisture move through to the paver surface and evaporate.

A sealer that has already clouded is a question ICPI sends to the sealer supplier, not a step printed here. All four whitening conditions, and ICPI's line on a cloudy sealer, are set out under why sealed pavers turn white.

SEK-Surebond's data sheet for SB-1300 reads: "SB-1300 can be applied immediately after surface installation, as it is breathable and will not trap naturally occurring moisture and efflorescence." The same sheet names the maker's own Efflo Off for efflorescence cleaning. That is one maker's description of one product, and it holds for that label only.

Techniseal's caution runs the other way for its film-forming Protectors: any new concrete product has the potential to produce efflorescence, and a film-forming coating carries a small risk of trapping it beneath the film. Techniseal's product guide says to wait until the pavers are dry before applying a Protector, because it could react with moisture and leave a white film on the surface.

ICPI credits one sealer family with an effect on efflorescence itself. Because silanes and siloxanes reduce moisture entering the concrete, they can deter efflorescence from appearing on the surface of concrete pavers, which ICPI says makes silane and siloxane sealers suitable on exterior areas for resisting efflorescence when a glossy surface is not wanted. Tremron, a Florida paver maker, sits with the general rule rather than the exception, advising sealing "after the natural process of efflorescence is complete."

None of the ICPI documents quoted here publishes a day count before sealing new pavers. The best known count comes from a paver maker: Tremron says, "It is recommended that you wait at least 30-60 days after installation before sealing," and adds that certain types of sealers can be applied instantly to a paver job. Seal 'n Lock, a Florida sealer maker, tells new installations to wait at least 30 days minimum or longer before its Super-Wet-Look goes on. Each count is that maker's, for its own pavers or its own product.

Efflorescence on the surface does not swap those counts for a new number. It adds Tech Spec 6's condition, that the efflorescence issues be under control. How long a brand new installation waits in general is answered under who decides how soon new pavers can be sealed.

Water is what brings efflorescence up, and water is also what a sealer has to wait out. ICPI notes that pavers installed in a dry period may need the next cycle of wet weather before efflorescence materializes, which is why a surface can look clear on the day and bloom later; that timeline is read step by step under whether efflorescence will go away on its own. Separately, ICPI's condition for most sealers is a completely dry surface, which it sets as at least 24 hours without moisture or surface dampness.

Seal 'n Lock's guide says its own Super-Wet can be applied even though the pavers are damp, a claim for that product rather than a description of most sealers. How the 24 hour condition works as a step in the job is set out under sealing as a sequence with conditions, and how it fits a wet month under what September does to a driveway. Which sealer suits a surface that may keep blooming is settled by that sealer's label and the paver maker.