Polymeric sand is designed to fill the gaps between pavers to keep them solidly in place, prevent weed growth, and allow for proper drainage from the patio.
Initially, some water will seep into the joint sand for the first few weeks but soon silts and dust in the air will fill any voids and water will then shed off the paver surface just like any other pavement.
Polymeric Sand Benefits
By sealing off the paver joints when it bonds it also prevents weed growth up through and burrowing insects from the top. It even helps prevent water damage from heavy rains as much of the rain water will not be able to seep under the pavers, therefore damaging the foundation underneath.
Polymeric Sand has many benefits, however, the biggest drawback is that it can be easy to mess up, especially if you don't follow the manufacturer's instructions.
A danger of using too much water too quick creates the possibility of washing away the polymers. Too little water used in the installation process could leave you with a fragile joint. If the joint is not properly watered to at least 2/3's depth, a hardened crust may form at the top of the joint.
Polymeric sand cures by drying. And in order to fully set, it needs to dry out completely.
Polymeric sand is the most popular and useful filler used under brick pavers. It is a mixture of fine sand, adhesive and is most widely used in paver joints. Typically, polymeric sand lasts for up to 10 years. But if you use high-quality polymeric sand, it can last for approximately 15 years.
When looking for alternatives to polymeric sand, you will also want to find high quality materials. There are other products, such as EnviroSAND, EnviroSTONE and EnviroPATH on the market that are able to stop water erosion from occurring.
If remov- ing polymeric sand, a hot water pressure washer will help to soften up the binders in the sand. Any tough to remove hardened areas, may require mechanical means to clean the joint. Take caution with natural stone or thin style pavers and be sure to avoid disturb- ance of the bedding sand underneath.
Protect from rain for at least 12 hours. No sealer is required. Sand remaining on paver faces can create a slight haze after wetting. A minimum of 24 hours drying time is required prior to allowing significant foot traffic and 48 hours for vehicular traffic on the paver surface.
When pavers are first laid, a block or brick wall is built there is often latent water present in the product. This water may be present due to the manufacturing process, product sweating from long-term packaging, water being added to the product during or after the installation or site moisture.
Sand allows water to drain through it more easily than silt and clay so more water should have drained through the sandy soil than the potting soil.
It's simple science. Water moves in between things and by adding pavers to your landscaping, you're ensuring there are cracks and joints between them, which allows water to drain through. One thing to remember though is to allow sufficient space between pavers to allow water drainage.
Pavers are great for patios, since they allow water to seep through and not form puddles and pools.
Filling large gaps between paving slabs can be easily achieved with wet brush-in joint filler or polymeric sand. Wet brush-in filler is more flexible, making the joints less susceptible to cracking as the temperature changes throughout the year.
Can you apply polymeric sand twice? No, new product won't adhere to the old. You have to remove the old polymeric sand and then apply fresh product for the best result.
Moss. CasaScapes polymeric sand will not cause nor prevent moss, mold or mildew. Moss, mold and mildew are caused by certain on-site conditions including excess moisture, shade, absence of ventilation, inadequate cleaning or maintenance, presence of soil or other organic debris left on the product.
Polymeric sand hardens in place when exposed to moisture so the sand particles bond together and are more resistant to ants mining through it.
The minimum drying time required for polymeric sand is 24 hours while it takes minimum of 12 hours to cure. But for the vehicular traffic is only allowed on pavers after 48 hours. So, it is wise to avoid foot and vehicular traffic during this process.
Traditionally, concrete paver manufacturers have recommended waiting at least 90 days after polymeric sand installation to apply a protective sealant to a paver surface. Nowadays, a 30 day delay is sufficient to allow the evaporation of any remaining natural efflorescence contained in the pavers.
Polymeric Sand Not Hardening
If it is able to penetrate the sand, then there is a problem. Typically this occurs because there was a rainfall shortly after the installation which caused the sand not to set, the sand was watered for too long, or there is not proper drainage in the base.
To maintain polymeric sand joints, keep a bag of this high-grade sand at hand so that you can use it whenever the need arises. You need to keep the package away from sunlight in a dry place. Do not take the sand out of its package unless you are applying it.
Generally speaking, you'll want to perform three rounds of watering. The initial showering should be done at a height of about 4 ft. Wait no more than three to four minutes before performing the second round of showering at a height of about 2 ft. Lastly, shower and rinse simultaneously at a height of 2 ft.