Do Pavers Need to Be Re-Sanded Before Sealing?

What does joint sand actually do?

Joint sand is not cosmetic. It is structural. Every paver in your driveway or patio relies on the sand in the joints to lock it in place. The pavers sit on a compacted base, but they stay where they are because the sand in the gaps between them creates friction. Without sand in the joints, the pavers can shift sideways. Shift far enough and the whole surface starts moving.

Joint sand also stops the base from washing out. When joints are full, water runs across the surface and off the edges. When joints are empty or low, water goes straight down into the base material. Over time, that washes the fine particles out of the base and creates voids underneath the pavers. That is when you start seeing low spots, rocking pavers and eventually cracked units.

On a properly sanded driveway, the joints are full to within an eighth of an inch of the paver surface. On a driveway that has not been sanded in years, the joints can be an inch deep or more, filled with nothing but dirt and weed roots. That is not a cosmetic issue. That is a structural failure in progress.

What happens if you seal over failed joints?

Three things go wrong, and they all happen faster than you expect.

The sealer bridges the gap and then cracks. Sealer is designed to coat a solid surface. When you spray it over a half-inch gap where the sand should be, it forms a thin film across the top of the void. That film has nothing solid underneath it. Within weeks, foot traffic and vehicle weight crack the film. The sealer edges peel back, water gets in, and the whole joint is compromised.

Weeds grow through from underneath. If the joints contain dirt and organic material, sealing over them does not kill the weed seeds. It traps them underneath a permeable layer. The weeds grow through the sealer film within a month or two. Now you have weeds growing through a sealed surface, which is harder to fix than weeds on an unsealed one.

The pavers keep moving. Empty joints mean nothing is holding the pavers in place laterally. The sealer on the surface does nothing to stop lateral movement. The pavers shift, the sealer cracks at the edges, and you end up with a sealed surface that already has hairline cracks running through it. The whole job fails from the bottom up.

How do I tell if my joints need re-sanding before sealing?

Three simple checks you can do in five minutes with no tools.

The depth test. Take a key or a flathead screwdriver and poke it into a few joints in different parts of the driveway. If it goes in more than a quarter inch before hitting firm sand, the joints are low. If it sinks to the handle, the joints are empty.

The weed test. Are there weeds growing out of the joints? Even if you pulled them, the roots and organic material are still in the gaps. Spraying kills the visible weed. It does not remove the seed bed. That organic material has to come out before sealing.

The rain test. After a heavy afternoon storm, look at the driveway. Is water pooling in spots? Are there small channels of sand washed across the surface toward the street? Both are signs that joint sand is washing out faster than it should. The joints need topping up before they get any lower.

Why do some companies skip this step?

Skipping re-sanding cuts the labour time by more than half. Cleaning old organic material out of every joint, washing the lines clear and applying fresh sand evenly across the whole surface is the slowest part of a paver restoration job. It cannot be done quickly. It takes hours of hand work.

A crew that skips this step can do two or three driveways in a day instead of one. The jobs look shiny when they leave. The customer is happy for about six months. Then the sealer starts peeling at the joint edges, the weeds come through and the pavers shift. The customer calls back and is told the sealer failed, not that the preparation was incomplete.

You can spot a quote that skips sanding before you book. It will be noticeably lower than other quotes, it will mention sealing but say nothing specific about joint preparation, and when you ask what happens with the joints, the answer will be vague. "We seal the whole surface" is not the same as "We clean out every joint and refill it with stabilising sand before sealing."

What a complete job looks like: clean, treat, re-sand, seal

A proper paver restoration follows four steps in order. None of them can be skipped without compromising the result.

How to check a company will do it properly before you hire them

Ask three questions when you get a quote. The answers will tell you everything.