How to Replace Polymeric Sand in Paver Joints, Step by Step

If your paver joints are washed out, cracked or full of weeds, topping them up rarely holds. Learning how to replace polymeric sand properly means removing the old joint material, cleaning and drying the pavers, then installing fresh sand exactly the way its data sheet describes.

In short: dig the old sand out to at least the minimum joint depth your new sand requires (1-1/2 in for Gator Super Sand G2, Gator Maxx G2, SEK PolySweep and Techniseal HP NextGel, per their data sheets) without disturbing the bedding sand. Let everything dry completely, sweep in the new sand, compact, set the level 1/8 in below the paver top, water activate and let it cure. If you plan to seal, wait for the time on the sand's data sheet.

Follow the instructions on your bag and the manufacturer's current data sheet for every step. The figures below come from those data sheets.

When joints need to be redone

Replacing joint sand makes sense when:

• Joints have washed out or dropped well below the paver surface.
• The sand is cracked, crumbling or stays soft.
• Weeds, moss or ants have moved into the joints.
• You are about to seal. The Alliance Gator sealer data sheets say to remove all contaminated jointing material and replace it with polymeric sand before sealing.

If pavers rock or have settled, fix the base first. The Gator Maxx G2 data sheet states that all pavers must be completely interlocked for vehicular and pedestrian use, and no joint sand will hold moving pavers in place.

Tools for removing old polymeric sand

The hardest part of how to replace polymeric sand is getting the cured material out of the joint. These are the tools we carry for the job, most of them in our sweeping and cleanup tools collection:

• Scraper and wire brush: our long handle wire brush with metal scraper lets you rake hardened sand out of joints while standing.
• Water broom: the SRW Jet Sweep water broom attachment flushes loosened material out along a joint line.
• Leaf blower: a cordless blower such as the Milwaukee M18 compact blower clears dry debris and, later, sand residue.
• Rubber mallet: for resetting a loose paver, and for settling sand in natural stone joints where the data sheet calls for it.

Whatever you use, the Gator data sheets warn to be careful not to disturb the bedding material under the pavers. If you flush with water, keep the stream out of the bedding layer and plan for extra drying time.

How to replace polymeric sand, step by step

1. Remove the old joint material

Take out everything, not just the loose top. The Gator Super Sand G2 and Maxx G2 data sheets say to remove existing jointing material, then install the new sand a minimum of 1-1/2 in deep. For SEK PolySweep X-Treme, the minimum depth is 1.25 in.

2. Clean the surface

The PolySweep data sheet says to sweep or blow off the surface and do spot and overall cleaning before installation. If you will seal later, treat oil or rust stains now. The Gator Shampoo data sheet states it will not negatively affect polymeric sand joints.

3. Let everything dry completely

This step causes more failures than any other. Gator's G2 sheets say pavers must be completely dry and joints must not be damp, or the sand activates early and sticks to the surface. SEK and Techniseal both require a dry surface and dry joints.

4. Install the new sand

Do not blend new sand with leftover old sand, whether you use Gator Super Sand G2, PolySweep or Techniseal HP NextGel. Gator's G2 sheets say not to use other materials in the joints, SEK says not to mix or dilute PolySweep, and Techniseal says not to mix HP NextGel with cement, sand or any other material. Then:

1. Sweep sand into the joints with a hard bristle broom until full, leaving some on the surface.
2. Compact. The Super Sand G2 data sheet calls for a vibratory plate compactor (rubber pad recommended), in several directions, and notes about 30 to 50% of the sand drops after the first pass.
3. Refill and compact again until joints are full.
4. Sweep off the excess, leaving the sand at least 1/8 in below the paver top or the bottom of the chamfer.
5. Remove residue from the surface with a soft broom or blower, as your data sheet directs.

5. Water activate

Watering differs by product, so read yours closely:

• Gator Super Sand G2 and Maxx G2: starting at the lowest point, shower 30 sq. ft. for at least 30 seconds, or until the sand repels water and it collects on the joints.
• SEK PolySweep: mist no more than 500 sq. ft. at a time, let it soak in about 5 minutes, and repeat 3 up to 4 times with gradually more water.
• Techniseal HP NextGel (pavers on a draining base): shower a 200 sq. ft. section 10 to 15 seconds, then immediately wet the same section for 30 seconds.

Cure times and weather limits by product

Sand	Joint width	Minimum depth	Weather after install	Temperature
Gator Super Sand G2	1/8 to 2 in	1-1/2 in	Rain safe 15 minutes after activation	Above 32°F
Gator Maxx G2	1/8 to 4 in (2 in on overlays)	1-1/2 in	15 minutes (traditional base), 24 hours (overlay)	Above 32°F
SEK PolySweep	Up to 3/4 in	1.5 in	No rain for at least 12 hours	Average air temperature above 35 degrees for 48 hours
SEK PolySweep X-Treme	Up to 4 in	1.25 in	No rain for at least 12 hours	Average air temperature above 35 degrees for 48 hours
Techniseal HP NextGel	1/16 to 4 in	1.5 in	Withstands unexpected rain after 60 minutes; should dry completely (24 to 48 hours minimum) before rain	Above 32°F for 48 hours

A few more curing notes from the data sheets: PolySweep curing can take up to 24 hours or longer, and cool, damp, overcast weather slows it. The HP NextGel data sheet allows foot traffic immediately and vehicles after 48 to 72 hours, and restricts pressure washers for the first 30 days. Turn off sprinklers during curing (SEK, Techniseal).

Sealing after you replace polymeric sand

Sealing is optional. If you plan to seal, the wait depends on the sand in the joints, so it is worth checking before you pick a product:

• Gator sand under Gator sealers: at least 48 hours, no rain, at the sealer's minimum temperature; then a full wash with Gator Efflorescence Cleaner and another 48 hours to dry.
• Techniseal HP NextGel: joints must be hard; typically at least 7 days and up to 30 days.
• SRW X-Treme and SimplyTough: 28 days before cleaning or sealing.
• SEK PolySweep: no sealing wait is stated; check the data sheet or ask SEK.

Cleaning up haze or residue

Sand left on the surface during watering can bond there. SEK's PolySweep sheet says to scrape cured residue with a plastic putty knife, then use boiling water and a stiff brush or a hot water pressure washer. The sheet also names SEK SureStrip, which SEK now lists as discontinued. Alliance says haze from Gator Maxx Sand residue will fade over time or can be removed with Gator Efflorescence Cleaner. Techniseal lists its Paver Restorer for haze created by some polymeric sands.

Frequently asked questions

Can you put new polymeric sand over old polymeric sand?

The manufacturers say no. Gator, SEK and Techniseal each tell you to remove the existing material and not to mix their sand with other material in the joint.

How deep should you remove old polymeric sand?

At least to the minimum depth for your new sand: 1-1/2 in for Gator Super Sand G2, Maxx G2, PolySweep and HP NextGel, and 1.25 in for PolySweep X-Treme.

Do you need a plate compactor for a repair?

For Gator G2 sands and HP NextGel, yes. Techniseal says mechanical compaction is mandatory and a smaller machine can be used for repair work and joint replacement. Where compaction is not possible and joints are wider than 1/4 in, Techniseal points to its NOCO polymeric joint.

How much polymeric sand do you need?

It depends on joint width and depth. PolySweep's data sheet lists 50 to 75 sq. ft. per 50 lb bag for joints up to 1/4 in, and Super Sand G2 lists 65 to 85 sq. ft. for 1/8 to 3/8 in joints on 2-3/8 in pavers. Use our polymeric sand calculator for your project.

Can you save leftover polymeric sand?

SEK says clean, excess PolySweep can be used on your next project if stored in its original packaging in a cool, dry place. For other brands, follow the storage notes on the bag.