Pavers are permeable and are laid with small spaces in between them. These features allow water to run through them and back into the ground below instead of sitting on top, like it would with asphalt or concrete.
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.
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.
An influx of water that sits for a long period of time can damage your paver surfaces by weakening the cracks or chips already present. If your pavers are already loose, they may collapse. Flooding can also lead to erosion when soil and rock are transported and deposited into the area.
Laying the pavers too tightly can actually cause some issues in the future. The recommended space between the pavers is 3 mm (⅛”).
Joint stabilization – If you don't have sand in the joints, rain water or pool water will run between the brick paver joints, and wash out the base aggregate sand material your brick pavers float on, (usually a 1.5” – 2” sand base) making your brick pavers loose, wobbly, uneven, sunken in or even raised up in some ...
Polymeric sand is a mix of different fine sands and other additives. When it is combined with water it creates a strong bond that is ideal for filling in joints in pavers. The ICPI endorses the use of polymeric sand. It is more flexible than fine dry sweeping sand but should not be used in driveways.
Pavers are great for patios, since they allow water to seep through and not form puddles and pools.
Theuse of polymeric sand increases the durability of the entire surface of the landscaped area. This minimizes the opportunity for water to seep below the surface of the interlocking pavers and into the sand and/or crushed stone foundation below.
Without proper drainage, paving stones are open to damage from the elements, especially water. Standing water weakens pavers, leading to chips, cracks, and even erosion. During colder weather, water that gets into these cracks and crevices can freeze, causing cracks to expand and worsen.
If your backyard doesn't have a natural slope, you can install a filter fabric or geotextile as they are commonly called. They are made of a permeable material that prevents the subgrade from moving while allowing water to drain. By installing this underneath your pavers, you could extend the lifespan of your patio.
Use Sand. When you're using filler mainly to solidity pavers and not for aesthetic reasons, then sand works best to seal the gaps between pavers. This is especially the case when the pavers are set close to each other, as is usually the case when using concrete pavers.
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.
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.
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.
Regular sand for paving is prone to erosion, damage from weeds and can make your pavers hard to wash without risking the loss of any jointing sand between the stones. Using polymeric sand, however, prevents weeds from taking root and holds pavers firmly in place thanks to the durability of its seal.
Improperly installed poly sand can ruin a great paver project. If you want your patio finished for tomorrow's family picnic, you should rethink your timeline.
Installing polymeric sand on a damp or wet surface could cause the sand and polymers to stick to the surface and become difficult to remove. After installation, a hard rain on polymeric sand that has not fully set up could result in polymeric sand all over the top of the pavers.
Non-permeable pavers do allow some water through the joints and into the soil, but not nearly to the extent of permeable pavers. For a patio that tends to collect pools of water, or for a driveway that slopes toward your house, permeable pavers will tend to be a better solution than traditional non-permeable pavers.
A Paver Patio with Poor Drainage
Sunken pavers can lead to water “pooling” on top of the patio. Pooling can also occur when the pitch isn't correct. This could lead to low areas that will always collect water.
Epic Fail #1: Too much or too little watering.
Using too much water can cause the sand to wash out of the joints. On the contrary, using too little can result in the product not setting up properly. Hazing can also occur if sand residue isn't fully washed off the surface of the pavers.
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 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.