Polymeric sand does not drain water. Instead of allowing water to pass through, it forms a solid, semi-flexible seal that forces rainwater to run off the surface of the pavers. Proper drainage relies on the slope of your patio and the aggregate base beneath the pavers, rather than the sand itself.
When polymeric sand gets wet, the water activates powdered glues mixed with the sand, causing it to turn into a gummy, cohesive gel. As it dries, this reaction binds the grains together into a hardened seal that locks pavers in place, prevents weeds, and resists erosion.
Although polymeric sand hardens when wet, it doesn't stay that way forever. Over time, it starts to break down, leaving the joints between your pavers looking uneven and messy. The plastics in polymeric sand can end up in the environment. Polymeric sand combines regular fine sand and bits of plastic activated by water.
No, cured polymeric sand is not water permeable. It is specifically designed to harden and act as a water-resistant seal that prevents weeds and ants from infiltrating paver joints.
No, you cannot put new polymeric sand directly over old polymeric sand. Because the old sand acts as a hardened barrier, a new thin layer will not bond properly. It will quickly flake, peel, and wash away after your first heavy rain.
Polymeric sand typically takes about 24 hours to set for light foot traffic and 24 to 48 hours to fully cure for heavier use or driveways. While it hardens to lock pavers together, it remains slightly flexible, meaning it does not cure to a rigid, rock-hard finish like concrete.
JOINT-IT SIMPLE is a fast, easy, long-lasting, and ready to use mix compound to fill joints of pavers, flagstones, and slabs permanently. The 44-pound bucket is available in 3 colors and comes with simple instructions. Unlike polymeric sand, this product leaves no hazing, dust, or stains on stone surfaces.
Most standard polymeric sand is semi-permeable, meaning it allows limited water drainage. However, it is not highly porous. The water seeps through the joints at a much slower rate than loose sand, relying primarily on a proper paver slope to direct the bulk of the water away.
Polymeric sand not hardening is usually caused by improper watering, uncooperative weather, or drainage issues. To fix it, you will generally need to scrape out the uncured sand, let the joints dry completely, and reapply fresh sand.
Polymeric sand can generally fill gaps ranging from 18one-eighth𝟏𝟖 inch to 4 inches wide. However, the ideal working range for most standard polymeric sands is between 14one-fourth𝟏𝟒 inch and 1.5 inches.
Typically, polymeric sand can last between 8 to 10 years, depending on various factors such as weather conditions, foot traffic, and proper installation. However, with regular maintenance, you can extend its lifespan significantly and ensure your pavers remain secure and attractive.
Polymeric sand usually washes away because the binding polymers were compromised during installation or because underlying drainage issues leave the sand perpetually wet, breaking down the glue.
Polymeric sand products such as TechniSeal NOCOSTORM or TechniSeal Polymeric Joint are designed to resist weed growth and to harden and stay in place for a long time.
Most standard polymeric sands require 3 to 4 distinct watering applications to fully saturate the sand from the top to the bottom of the paver joint. However, if you are using a newer, advanced formula (like Alliance Gator G2), you may only need 1 heavy watering.
Let the polymeric sand cure for at least 24 hours without disturbing the surface (manufacturer recommended time may vary). If area is used before the polymeric sand has fully dried and cured, the sand can be transferred to the paver surface, leaving behind a cloudy film or residue.
You should apply polymeric sand before you seal your pavers. Sealing locks the sand in place, prevents erosion, and protects both the stone and the joints from moisture and weed growth.
No, cured polymeric sand is not water permeable. It is specifically designed to harden and act as a water-resistant seal that prevents weeds and ants from infiltrating paver joints.
If polymeric sand gets rained on, what happens depends entirely on whether it has had a chance to cure. It needs a specific window of dry time to set properly.
Polymeric sand is significantly more expensive than regular sand ($20 to $90+ per 50 lb bag compared to $5 to $20) because it is a highly engineered material. Its price is driven by:
Epoxy and resin-based jointing compounds (like EASYJoint or Joint-It) are widely considered superior to polymeric sand. While polymeric sand is a budget-friendly choice for locking pavers, resin formulas outperform it by offering permanent flexibility, superior drainage, and the ability to install in wet weather.
Yes, sand drains water very quickly. Its large, coarse particles create big gaps that allow water to flow right through. While this prevents standing water, it also means the soil dries out rapidly and struggles to hold onto nutrients.
No, you cannot simply add new polymeric sand over an old layer. Doing so will cause the new sand to flake, peel, and wash away. Because polymeric sand relies on a binding agent activated by water, a new layer cannot bond properly to an already cured, hardened, and dusty surface.
Polymeric sand typically lasts 5 to 10 years before requiring a full replacement. However, its exact lifespan depends on the climate, foot traffic, and maintenance. Localized touch-ups are often needed every 3 to 5 years.
The best polymeric sands for hardscape projects are Alliance Gator Maxx G2, Techniseal HP NextGel, and DOMINATOR XL. These industry-leading options resist weed growth, withstand freeze-thaw cycles, and feature dust-free and haze-free formulas.
For block paving gaps, you should use kiln-dried sand or polymeric sand. Both are fine-grained and designed to interlock the blocks tightly, but they have different maintenance benefits.