Polymeric sand is a unique mixture of fine sands combined with other additives (polymers), that, when mixed with water, form a surprisingly strong binding agent that locks the sand particles together. It is particularly useful for filling the joints between pavers, including concrete pavers, brick pavers, and stone pavers. The binders lock the sand particles together, which helps secure the pavers into a uniform, durable surface.
Advantages of Polymeric Sand
Ordinary sand—the same material used to form a bed for setting pavers—can also be used to fill the joints between pavers, so why use polymeric sand? In fact, there are drawbacks to this product, such as the fact that it can stain your pavers (to remove the stains, some suggest scrubbing with vinegar). Nonetheless, the product is superior to regular sand in a variety of ways:
- It improves durability. The binding agents in this product help lock the pavers together. This will give your installation more strength over the long haul.
- Heavy rain will not wash the sand out of the joints between pavers. The silica and other binding additives in polymeric sand reduce the amount of water that can wash between the pavers and down into the base materials. This keeps the base foundation under the surface sturdy and intact.
- It deters weeds. Weeds are amazingly resilient and can grow almost anywhere. While using polymeric sand doesn't guarantee that weeds will never grow in your new walkway or patio, it does help considerably. Ordinary sand is much more inviting than polymeric sand as a home for weeds.
- It is resistant to ants. Ants will have a much more difficult time getting into and making homes in the spaces between your pavers if you use polymeric sand.
- It comes in different colors. Polymeric sand comes in a variety of colors, usually in different shades of gray and beige. Choose the color that goes best with your pavers. For example, a shade of gray looks good with flagstone pavers.
Purchasing Polymeric Sand
The same retailer who sold your pavers is likely to also sell polymeric sand. If not, check with your local home improvement store. This product usually comes in 20- or 40-pound bags, so it is relatively easy to handle. It is marketed under different brand names depending on the manufacturer. For example, Sakrete offers a product called Paver Set.
Equipment / Tools
- Leaf blower
- Push broom
- Vibratory tamper (optional)
- Garden hose
- Polymeric sand
- Vinegar (if needed)
Filling the cracks with polymeric sand is the last step in the larger project of installing a stone or brick paver patio, walkway, or driveway. The success of this final step depends in large part on the pavers being installed properly on firm, flat layers of gravel and paver sand—a type of sand much different than polymeric sand.
Spread Polymeric Sand
Make sure to work when the pavers are completely dry. Pour several small heaps of polymeric sand over the patio or walkway. Do not over-apply the sand, because the excess will be hard to remove. You can always add more sand, as needed. The goal is to completely fill the cracks between pavers, without leaving excess sand on the surface.
Sweep the Sand Into the Cracks
Using a push broom, brush the sand back and forth over the pavers to filter the sand down through the cracks between pavers. Brush in opposite directions to make sure all cracks are filled. Add more sand, if necessary, until all cracks are visibly filled with sand, without gaps.
Tamp the Pavers
To ensure that the sand fills the entire joint, run a vibratory compactor or tap the paves with broom handle to settle the sand and ensure the joints are filled completely. As the sand level drops, add more sand and repeat the sweeping and tamping process.
Clear the Surface of the Pavers
Before setting the sand with water, it is important that the surfaces of the pavers be free of sand because any excess will harden on the surface of the pavers and discolor them. A leaf blower works well for cleaning excess sand off the pavers. Make sure, though, not to blow sand out of the cracks between pavers. A fine brush can also work if you don't have a leaf blower.
Mist the Pavers
With a garden hose, spray a light mist over the area. This will activate the binding agent in the sand. Make sure not to wash the sand out of the joints. Let the joints dry completely for a day or two, then inspect the joints for any gaps. Additional sand can be applied to fill any remaining gaps.
Wash the Pavers, if Necessary
Should you find yourself with discoloring stains due to polymeric sand on the surface of the pavers, spray white vinegar over the stains, allow it to sit for about 1 hour, then wash away with soap and water.