Patio Paver Sanding
If you have a paver patio, walkway, or driveway and the sand needs to be replenished between the pavers, there are two alternatives. The best alternative is to use polymeric sand, which bonds the pavers together, keeps out weeds, and is less susceptible to ants. Before you go out and buy a bag of polymeric sand, read on so you know what is involved in getting the sand into the joints properly.
Polymeric sand is a granular material placed between the joints or seams in paver patios, walkways, and driveways. Its primary function is to improve the interlock and therefore the durability and stability of a paved surface. Until about five years ago, this function was performed most often with silica or torpedo sand. The sand would be swept between the joints of a paver patio or walkway, and its mere presence would enhance the interlock between pavers via friction between the pieces of pavement, thus resisting movement of the pavers. Often that sand would be stabilized by applying a sealer to the pavement; the sealer would help maintain certain characteristics of the pavers or stone and would harden the uppermost layer of joint sand, making it resistant to water washouts, ants, and weeds.
More recently, sand with polymers added to it has been quickly growing in popularity for this purpose. Its use has all but eliminated sand being washed out during a big rain storm. The polymeric sand provides a near-perfect prevention of weeds between pavers, washout resistance, and a barrier against ants.
In addition, polymeric sand provides greater durability of the pavement. With polymeric sand in place in a paver patio or pathway, water has less opportunity to seep below the hard wearing surface of the pavement and into the sand and/or crushed stone below. Without water beneath the pavement, silt and sand have no ability to migrate from one area to another, and the drier base and sub-base are less likely to deform under traffic loads because water, the great lubricator, is nowhere to be found. This means your paver patio or walkway look perfect longer when polymeric sand is used to fill the joints.
For the polymeric sand to adequately firm up in the seams between brick pavers or stone, the full depth of the joint needs to be filled with polymeric sand. Adding a bit of polymeric sand on top of existing joint sand will only provide a shallow depth of sand with an activated polymer, making it unable to resist ants, weeds, or washout/erosion. If you are retrofitting a patio with poly jointing sand, you should first clean out all existing sand from between the pavers. This is best done with a power washer, but can the done with a hose equipped with a high-pressure nozzle. If you do not remove the old sand, there will not be enough polymeric sand to seal the joint and bond the pavers together. You will need to remove enough sand so that you will be putting 1.5” to 2” of new sand into the joint. The patio must be completely dry before proceeding with the sand. This is a very important step; it really must be dry.
Before you start, make sure there is little or no chance of rain in the immediate future, as polymeric sand will stick to whatever surface it’s touching as soon as it gets wet and is very difficult to clean off the tops of pavers once it’s been activated. One Woodchuck described to me the hours of scraping polymeric sand off the surface of his patio with an ice scraper when he brushed wet sand on the surface.
Once you’ve finished washing the old sand from between the pavers down to a depth of 2”, you must wait until the pavers are thoroughly dried before proceeding. You can speed up this process with a leaf blower. You are now ready to spread the polymeric sand over the surface. It should then be swept into the joints between the pavers.
Once the sand has been swept in, special care needs to be taken to ensure that no stray sand is sitting on the face of the pavers. Check in corners, along steps, and anywhere else sand has a tendency to collect. You can either use a broom or a blower to gently clean off that last bit of sand prior to wetting.
Starting at the highest point of your patio, gently spray a water mist over the paved area, working toward the lowest part of the paved area, lightly soaking the pavers and sand. The objective is to try to wash any remaining poly sand dust or particles off the surface of the pavers while not washing the sand from between the joints. The water mist activates the polymers, which will begin to harden the sand. Most manufacturers recommend allowing the sand to cure/set for 10-15 minutes, then misting the area again with a light spray of water.
The sand may take a full 24 hours to completely activate and harden, but it only takes 20 minutes or so in a sunny area for the joint sand to harden enough that it doesn’t adhere to your boots and get deposited elsewhere on the face of the pavers.
Polymeric sand is the perfect solution for weeds, ants, and stabilizing your patio, but it must be installed properly. If you don’t think you are up to doing this job yourself, you can contact a contractor that does this type of work, and be sure to ask for and check his references. The other alternative is to use regular silica sand and be prepared to redo the job each year. You will also not get as good a weed control as with polymeric sand. On the positive side it is a much easier job and the wet sand will not adhere to the surface of your pavers.