Clean, re-sand, then seal. Done in that order sealer holds the joints and keeps the colour. Done out of order it traps dirt under a film that goes cloudy and peels within two seasons.
Sealer is a surface treatment, not a repair. Applied over joints that are half empty it runs down into the voids, sets, and leaves you with a surface that still moves but can no longer be re-sanded properly.
Applied over a surface that was not fully dry it clouds, and that haze does not come off without stripping. The sequence matters more than the product: clean the surface, let it dry, refill the joints with the right sand, then seal.
In Toronto we avoid sealing in late autumn because the surface rarely gets a two-day dry window. See what pressure washing removes, how polymeric sand is installed, and what efflorescence removal actually involves.
Cleaning and Sealing
How It Runs
Four steps to a surface worth sealing
Clean at the right pressure
Enough to lift dirt and growth, not enough to blast the joints out or etch the face of the block.
Let it dry
A full day or two depending on weather. Sealing damp pavers is what causes the cloudy white haze people call sealer failure.
Refill the joints
Polymeric sand swept in and set, because sealer over empty joints cannot be undone later.
Seal and cure
Applied at the coverage rate the product calls for, then left to cure before anything drives on it.
Order Of Work
Six jobs, and three happen before the fourth
Sealing is the one people ask for and the last one that should happen. A surface gets washed, it dries, the joints are refilled, and only then does sealer go down, because a film over an open joint runs into the void and sets there.
Staining and efflorescence are treated before the seal for the same reason: a film locks them underneath permanently. Sealing itself is optional, and on a shaded patio that stays damp it can slow drying and make things worse rather than better. We will tell you when a surface is not worth sealing rather than take the job.
