Sealing and re-sanding often get discussed as if they're alternative upgrades to pick between, but on block paving they're not competing options at all — they're two steps in the same process, and the order they happen in isn't negotiable.
Understanding why re-sanding has to come first explains a lot about why a sealed drive with loose or missing joint sand tends to disappoint people who paid for the finish without the groundwork underneath it.
Why the sequence only works one way
Sealer is designed to sit on and bind the surface, including sealing the top of the joint sand in place. Applied over an empty or under-filled joint, the sealer skins over a gap rather than a solid, sand-filled channel — it looks fine on the day and then cracks or sinks as the joint settles.
Re-sanding first gives the sealer something solid to bond to across the whole surface, joints included, which is the entire point of doing both jobs on the same drive.
What happens if sealer goes down before re-sanding
- The sealer bridges over empty or thin joints instead of locking sand in place beneath it.
- Movement in the blocks cracks the sealer film along the joint lines first.
- Weeds can still find a way through a thin or bridged joint, defeating one of the main reasons for re-sanding at all.
- Any later attempt to re-sand properly means disturbing and likely damaging the sealer that's already down.
Planning a job that needs both
A drive that needs full re-sanding and sealing in one project generally runs as: clean, treat, re-sand, allow the surface to dry and settle, then seal. That drying window between re-sanding and sealing matters as much as the order itself — sealing over damp sand traps moisture under the film.
If only one of the two is being done this time, re-sanding without sealing is a perfectly complete job on its own. Sealing without re-sanding on a drive with failing joints is the combination that causes problems.
When re-sanding alone is the right stopping point
Not every drive needs sealing at all — it's a finish choice, not a requirement. If the joints are refilled and sound but the colour and gloss of sealing aren't wanted, stopping after re-sanding is a legitimate, complete outcome rather than a job left half done.