Gator Nitro Joint Sand: How the Air Cure Jointing Sand Works

Gator Nitro Joint Sand works differently from the polymeric sand most people know. Instead of a dry sand you activate with a hose, Alliance describes Nitro as a ready-to-use mix of calibrated sand and a proprietary resin that cures when exposed to air, hardening from the top of the joint to the bottom. It can go in during wet or dry weather, and it is permeable once installed.

That permeability is the part to plan around. Alliance states that Gator Nitro can only be used over a drainage base, and that the pavers must not move before or after jointing. This guide covers what the product is rated for, the base systems Alliance approves, the installation steps, and coverage, using figures from the Gator Nitro Joint Sand technical data sheet updated July 21, 2026.

What Gator Nitro Joint Sand is

Alliance Gator Nitro Joint Sand ships pre-mixed and needs no mixing. Here is how it differs from a typical water-activated polymeric sand:

Feature	Typical polymeric sand	Gator Nitro Joint Sand
How it sets	Dry sand, activated with water after it is in the joint	Resin cures on exposure to air, top to bottom
Surface at installation	Must be completely dry	Must be pre-wet and kept wet throughout
Weather	Needs a dry window after activation	Can be installed rain or shine; rain delays setting
Water through the joint	Varies by product	Permeable when installed
Packaging	Usually 50 lb bags	40 lb pails

Alliance also lists a 24 month shelf life when stored in a cool area, under cover and out of direct sun, at temperatures from -22°F to 86°F. The working time once you start is approximately 45 minutes.

Gator Nitro Joint Sand specifications

Specification	Per the data sheet
Joint width, concrete pavers, slabs, natural stone, wetcast	3/16 in to 2 in
Joint width, outdoor porcelain tiles, pavers or slabs	1/8 in to 1/4 in
Joint depth	3/4 in minimum, 3-1/8 in maximum
Installation temperature	Above 37°F
Open to traffic	After initial setting, approximately 18 hours in dry conditions above 75°F
Full strength	28 days
Pressure washing	Not for at least 28 days
Uses	Patios, pool areas, walkways, residential driveways with light vehicular use

Why the base has to drain

Because Nitro is permeable, water that lands on the surface passes through the joints into the layers below. Alliance's testing on joints alone (no base underneath) measured water permeability from 0.7 gallons per minute per sq ft for Black up to 2.3 for Grey, and notes that these values drop significantly once a base, dust and debris restrict flow. The practical point is simple: the base has to accept that water and move it away. Alliance states Nitro can only be used on a drainage base application.

Two more conditions from the data sheet matter here:

• No movement. Pavers, slabs, stone or tiles must not move before or after jointing. Alliance says movement or rotation comes from improper sub-base preparation, that Nitro will not prevent it, and that any movement voids the warranty.
• A bedding layer that chokes. Nitro can be used over chip stone (1/8 in to 1/4 in, ASTM No. 9) that locks together, but not over aggregate with large voids, because the sand will migrate down into them.

To keep the joints permeable, Alliance recommends cleaning the whole surface with Gator Shampoo and periodically pressure washing to clear dirt and debris, starting no sooner than 28 days after installation.

The base systems Alliance approves

The data sheet lists five base options. Each starts with Gator Fabric GF4.4 covering the bottom and sides of the excavation.

1. Traditional drainage base: 4 to 6 in of compacted 0 to 3/4 in crushed stone, a 1 in setting bed of sand or chip stone, and Gator Edge nailed into the base.
2. Permeable base: 4 to 6 in of compacted 1-1/2 in plus crushed stone, 2 in of well-compacted 3/4 in net stone, a 1 to 2 in chip stone setting bed, and Gator XTreme Edge troweled under the paver edge.
3. Hybrid base: 4 to 6 in of compacted 3/4 in crushed stone, a 1 in chip stone setting bed, and Gator XTreme Edge. Nitro can be installed only 90 minutes after XTreme Edge is applied.
4. Gator Base, pedestrian use only: Gator Base panels extending 6 in past the paved area, a 3/4 in to 1 in sand or chip stone setting bed, and Gator Edge screwed to the panels.
5. Gator Base with the Gator Tile System, pedestrian use only: for porcelain, using Gator Spacers, Gator XP glue, Gator Tile Edge and Gator Base Screws. Note that Alliance lists Gator Nitro X Fine Joint Sand as the jointing component of this system.

Surfaces, pools and driveways

Nitro is listed for concrete pavers, concrete slabs, natural stone, wetcast stone, and outdoor porcelain tiles, pavers or slabs. Residential driveways with light vehicular use are included; Gator Base installations are for pedestrian use only.

Around in-ground pools, Alliance makes two points mandatory: a slope of 1/8 in per linear foot away from the pool, and mortar, not Nitro, in the joints of pool coping blocks. Nitro can be used on the rest of the pool deck. All surfaces need a drainage slope for the product to perform as intended.

How to install Gator Nitro Joint Sand

Alliance notes installation is easier with two people. Follow the pail instructions and the current data sheet at the time you install.

1. Check the base. Confirm there is no movement in any paver, stone or tile.
2. Wet the area. The paving surface must be pre-wet and stay wet throughout, or staining may occur. If the surface is dry or the temperature is high, use more water.
3. Spread and soak. Spread the contents of the pail over the surface and thoroughly soak it with water while using a squeegee or hard bristle broom to spread and mix it, letting it flow into the joints.
4. Push it in diagonally. Keep applying water while pushing the sand diagonally across the surface. Alliance says this action compacts and forces the material into the joints. Make sure joints are completely filled before moving on. Use a hard bristle broom on textured surfaces and for final joint height.
5. Set the height and rinse. Fill joints to 1/8 in below the top surface, or 1/8 in below the chamfer. Shower the surface to rinse excess material off, then repeat on the next section.

Joints are effectively rain safe immediately, though rain delays setting. After heavy rain during installation, Alliance says you may need to return and touch up joints once the weather clears.

Coverage per 40 lb pail

Coverage depends on joint size, and darker colors cover slightly less. These figures are from the data sheet:

Joint (reference unit)	Beige	Grey	Silver	Black
1/8 in joint, 24 x 24 x 3/4 in porcelain tile	537 sq ft	500 sq ft	537 sq ft	463 sq ft
3/16 in joint, 12 x 12 x 2-3/8 in paver	35 sq ft	33 sq ft	35 sq ft	31 sq ft
3/4 in joint, 12 x 12 x 2-3/8 in paver	15 sq ft	14 sq ft	15 sq ft	13 sq ft
1 in joint, 12 x 12 x 2-3/8 in paver	11 sq ft	10 sq ft	11 sq ft	9 sq ft

For other unit sizes, estimate with our polymeric sand calculator and compare against the chart above. The Nitro color samples include all four colors.

What Alliance's testing and warranty cover

Alliance reports that Nitro joints immersed for 7 days in 4 percent bleach and in a 50 percent calcium chloride (de-icing salt) solution showed no effect, while noting that several months of exposure would likely have an effect similar to what the paving itself experiences. The product carries a 5-year limited warranty for residential use and 1 year for commercial or other uses, on the condition that you first test a small area of about 4 sq ft. Alliance also states that Nitro will not cause or prevent moss, mold or mildew, which come from site conditions like shade, moisture and debris.

You can download the full data sheet from our TDS and SDS library.

Frequently asked questions

Does Gator Nitro need water to harden?

No. It cures on exposure to air. Water is used during installation to keep the surface wet and help the sand flow into the joints.

Can you install Gator Nitro in the rain?

Yes. Alliance says it can be installed rain or shine and is effectively rain safe immediately, although rain delays the setting process.

Can Gator Nitro be used on a driveway?

Residential driveways with light vehicular use are listed on the data sheet, over an approved drainage base. Installations on Gator Base panels are for pedestrian use only.

Can you use Gator Nitro over a concrete slab?

Alliance approves Nitro only on a drainage base application, using one of the base systems listed on its data sheet.

How long before you can walk on it?

Approximately 18 hours in dry conditions above 75°F. Full strength takes 28 days, and pressure washing should wait at least 28 days.