Efflorescence

Is efflorescence a sign something was installed wrong?

Usually not. New concrete pavers commonly show efflorescence in their first year as residual lime works its way out of the material — it's a curing process, not an installation defect. Efflorescence that shows up on a much older surface, or that keeps returning heavily after cleaning, is more often a sign that water is moving through the paver from underneath, which is worth having assessed rather than just cleaned away repeatedly.

How do you actually remove efflorescence?

Plain water and a stiff brush clear light efflorescence on most surfaces. Heavier deposits typically need a cleaner formulated for the specific paver material, since an acidic cleaner that's safe on concrete can etch or discolor natural stone. Sealing the surface afterward is the step that actually slows efflorescence from recurring — cleaning alone just resets the clock until the next bloom.

Does sealing prevent efflorescence for good?

Sealing significantly reduces it by limiting the moisture movement that carries salts to the surface, but it doesn't eliminate the underlying mineral content in the material. A surface that was efflorescing heavily before sealing may still show occasional light bloom afterward — the honest expectation is much less, not none.