Polymeric Sand

Polymeric sand is graded jointing sand blended with a binder. You sweep it into paver joints, mist it with water, and it sets firm. Done right it locks pavers together, keeps weeds and ants out of the joints, and stops the sand washing out in heavy rain. Done wrong it hazes over the surface, never hardens, or cracks out within a season. The difference is almost never the brand. It is the joint width, the prep, and the watering.

This is every polymeric sand we carry, from Alliance Gator, Techniseal, SEK Surebond, SRW and ROMEX, in one place. We decant 2 oz color samples of all of them, so you can put the real granule color against your own pavers before committing to a 50 lb bag. Not sure how many bags you need? Use the polymeric sand calculator.

Start With Your Joint Width

Joint width is the decision that matters most. Every polymeric sand has a maximum joint it is rated for, and using one outside its range is the single most common reason a job fails. Measure your widest joint, not the average one, and pick from the row that covers it. Every rating below is taken from the manufacturer figure on the product page it links to.

Two things people miss. A sand rated to 4 inches works perfectly well in a half inch joint, so if you have a mix of widths, buy for the widest. And "intersecting spaces", the wider gaps where three or four stones meet, are usually rated separately on the bag. If those are wider than your joints, they are the number that counts.

How Polymeric Sand Actually Works

The sand does nothing on its own. What makes it polymeric is a dry binder mixed through the grains. When you mist the joint with water, the binder activates and glues the grains to each other and to the sides of the paver. As it dries it firms up into a joint that flexes a little with freeze and thaw but does not wash out, blow out or feed weeds.

That is also why the two failure modes are opposites. Too little water and the binder never fully activates, so the joint stays soft or dusty. Too much water in one go, or water sitting on the paver face, and the binder floats up and sets on the surface as a haze. The watering steps on the bag are not generic advice, they are the manufacturer telling you how much water that particular binder needs, and they differ from product to product.

Which Brand Should You Buy?

Honestly, for a standard patio with joints under an inch, any of the products in the first row of the table will do the job well if you prep and water it correctly. Where the brands separate is on the harder jobs.

• Alliance Gator has the widest range, from Super Sand Bond for tight joints to Dust Bond for 6 inch flagstone, and Maxx G2 is the polymeric sand we sell the most of, by a wide margin. If you want one brand that covers every job, this is it.
• Techniseal is the pro-series choice. HP NextGel handles joints from 1/16 inch to 4 inches and is built not to haze or dust, and NOCO is the one for jobs where you cannot run a plate compactor.
• SEK Surebond PolySweep is the low haze option for tight joints, with PolySweep X-Treme carrying the same chemistry out to 4 inches.
• SRW X-Treme is the wide joint specialist, rated to 6 inches and rain safe 20 minutes after activation, which matters when the forecast is not cooperating.
• ROMEX is not polymeric sand at all but a resin jointing mortar. It is what you use when the joint has to stay permeable, and it is the second best seller in this collection behind Maxx G2. Ecofine is the one most people want.

If you want to see the ratings, set times and colors of every brand in one table, that is what the side by side comparison is for.

Polymeric Sand vs Regular Sand

Regular jointing sand is loose. It washes out in the first heavy rain, it blows out under a leaf blower, ants tunnel through it and weeds seed in it, and you sweep more in every spring. Polymeric sand costs more per bag and is less forgiving to install, but once it has set it stays put for years. For a driveway, a pool deck or any patio you do not want to re-sand every season, it is the better buy. For a job you expect to lift and relay, or a base that is still settling, loose sand is fine. There is a longer version of that answer in polymeric sand vs regular sand.

How To Install It

The short version. The bag will have the exact watering sequence for that product and you should follow it over anything written here.

1. Wait for dry pavers and a dry forecast. Dry all the way down into the joint, not just on top, and enough clear hours afterwards to cover the cure window on the bag.
2. Sweep the sand in. Push broom, working diagonally across the joints so the bristles do not drag the sand back out. Fill to within about an eighth of an inch of the paver surface.
3. Compact. A plate compactor with a protective pad, or a hand tamper on a small job, settles the sand to the bottom of the joint. Top up and sweep again. Skip this step and the joint will sink.
4. Blow the surface clean. Every grain has to come off the paver face. Leaf blower on low, held at an angle so it does not scour the joints. Then look across the surface at a low angle for the film you cannot see standing over it.
5. Mist, do not flood. Shower setting, in the stages the bag describes, letting each pass soak in. Water sitting on the surface is the cause of haze.
6. Keep everything off it. Foot traffic and rain for the period on the bag, longer for vehicles.

There is more detail, including what to do at the edges and around steps, in polymeric sand installation tips.

Why Polymeric Sand Jobs Fail

Nearly every failure traces back to one of five things, and all five are avoidable.

• Water. Too little and the binder never activates. Too much and you flood the binder out of the joint. Follow the watering steps on the bag exactly, they are not generic.
• Sand left on the surface. Any sand still sitting on the paver face when you water it will set there as haze. Blow the surface completely clean first. If it has already happened, here is how to get polymeric sand off pavers.
• Damp joints. The joint has to be dry all the way down before you sweep sand in. Sand poured into a damp joint sets in a crust and stays soft underneath.
• Under filling. Joints need to be filled to within about an eighth of an inch of the surface. Short joints crack and wash out.
• Rain too soon. Check the product cure window against the forecast. Most need several hours clear.

Coverage and How Much To Order

Coverage depends on joint width, joint depth and paver size, so a bag that does 100 sq ft of tight joints might only do 30 sq ft of wide flagstone. A 50 lb bag typically covers 30 to 100 sq ft. Run your numbers through the calculator rather than guessing, and order a spare bag. Running out mid job means a visible seam where the two batches meet, and the color can shift slightly between production lots.

Order a Color Sample First

Sand color looks different in a photo, in the bag, and cured in a joint next to your pavers. We fill 2 oz color samples of every brand and color we carry so you can see the real thing before ordering a pallet. Nobody else does this, and it costs less than getting the color wrong.

Quick Answers

Does polymeric sand harden like concrete?

No. It sets firm enough to lock the pavers and shed water, but it stays slightly flexible so it can move with freeze and thaw. If it is hard as concrete it will crack out; if it is still dusty a day later, it did not get enough water.

How long before it can get rained on?

It depends on the product. Some are rain safe within minutes of activation, most want several clear hours, and the number is printed on the bag. Check that against the forecast before you start, not after.

Can I put new polymeric sand over old?

Only if the old joint is removed or well below the surface. Polymeric sand needs joint depth to bond, so a thin layer swept over a full joint will flake off. Scrape or pressure wash the old material out first.

Does it stop weeds and ants?

It makes the joint a poor place for either. Seeds have nothing loose to root in and ants cannot tunnel a set joint. It is not a herbicide, so a seed that lands on top can still sprout if it finds dirt.

Will it work on flagstone and natural stone?

Yes, but only the wide joint products. Standard sands are rated to an inch or two and flagstone joints are often three to six. Use the 4 inch and 6 inch rows of the table above, and note that some products are specifically made not to haze natural stone.

What about porcelain pavers?

Porcelain has very tight joints and a smooth face that shows haze badly, so use a product rated for it, such as Techniseal NextGel or Gator Nitro, and blow the surface completely clean before watering.

Not Sure Which Sand You Need?

Tell us your joint width, paver type and location and we will tell you which of these actually fits, including when the cheaper one is the right one. Call or text (856) 418-4895 or email info@polymericsandstore.com.