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What should you use to fill the joints in between pavers? Does it matter if you use just regular sand? Do you need to spend the money to use polymeric sand? What are the differences between the two? All of these questions get answered as we discuss why you should not use regular sand to fill your joints and why you may want to consider polymeric sand for your paver project.
What to Use to Fill in Between Pavers
A jointing compound is used for the gaps between pavers. This can range from a loose jointing sand to a hardening polymeric sand, though several alternatives are beginning to come to the North American market to provide a range of options depending on the application.
Filling the joints of the pavers contributes to the vertical interlock that is achieved by interlocking pavement, which adds to the strength of the overall project. Without this material, the interlock would move around under the pressure of a dynamic load on the surface of the pavement. This is why it is such a crucial step in the process of installing pavers. However, the right material must be used in the installation of this jointing material.
Sand is a common material used in the installation of jointing material as its smaller granules allow it to consolidate to the bottom of the joints with the assistance of mechanical compaction. The sand that is used in this installation needs to be formulated for the use in paver joints. There are two types of sand that are traditionally considered for this installation: jointing sand or polymeric sand.
Jointing Sand for Pavers
Jointing sand is typically a fine graded sand that is subangular or angular in the larger granule sizes within it. This allows for it to prevent washout, but inevitably it will washout over time and will be subject to weed growth more so than polymeric sand. To lock this material into place between the joints of the pavers, you can apply a joint stabilizing sealer.
This material has a fairly simple installation. A bag is dumped onto the paving surface and swept into the joints of the material. Both the surface of the pavement and joints of the pavers need to be dry to allow for it to reach the bottom of the joint. Additionally, the sand itself should be dry. Once the material has been swept around the entire surface of the project and the joints are full, a plate compactor with a protective pad or a protective layer between the surface of the stone and the compactor can be used to consolidate the jointing sand to the bottom of the joints. You can then repeat this process until the jointing sand is 1/8″ below the surface of the pavers or the bottom of the paver chamfer. You will also want to hold a bag of jointing sand to top up the joints whenever you need to if you do not opt for a joint stabilizing sealer.
Polymeric Sand for Pavers
Similar to jointing sand, polymeric sand is a finely graded sand with polymers and additives that differ between manufacturers that when activated create a bonding agent that provides strength to the joints of the paving system. It does not require a joint stabilizing sealer as it is stabilized through the activation of the sand through watering.
Polymeric sand is a little bit more difficult and at least double the price in comparison to jointing sand. There are more problems that can occur with a poor installation of polymeric sand that requires some training before installing. It is installed using the same steps as above, except the final activation of the sand includes a watering as specified by the manufacturer. Because of this watering and the time needed for the polymeric sand to cure, the paving surface cannot be sealed for at least 30 days after the installation of the polymeric sand.
Another one of the benefits of polymeric sand over jointing sand is that it is available in a variety of colors including tans, greys, black, and white. Additionally, it prevents washout, insects, and the growth of weeds. However, these benefits only come with a quality installation of it.
Can You Use Regular Sand Between Pavers
In short, no you cannot use regular sand between pavers. You should not use just any sand that you can get a hold of to put in between your paver joints. This will lead to the washout of the pavers and poor vertical interlock which is important to the strength of the interlock pavement system.
What is regular sand though? Play sand, masonry sand, beach sand, all of these sands that you may encounter are not suitable for paver joints because of the size and shape of the granules within it along with the finer material. Studies have shown that a larger granule within the sand joints actually provides better strength to the system. Additionally, granules that are less round in shape tend to provide a better lock between them to prevent washout.
That is why if you are opting for a “regular” sand for your pavers, it is best to find a jointing sand. This sand has been formulated to be a sand that has larger and more angular or subangular granules that prevent washout of the material. However, washout of any loose material installed into the joints of the pavers is inevitable. That is why we opt for a polymeric sand in the majority of our paver projects.
Using quality products will yield quality results with your paver installation. Improper installation techniques and methods will create a headache moving forward as your pavement system ages. Polymeric sand is definitely more expensive than the jointing sand alternative, but it does hold some advantages especially if you do not opt to use a joint stabilizing sealer. Also, do not try to fill up the joint partially with a less expensive material and then topping it off with polymeric sand to save a dollar. This will lead to the failure of your polymeric sand.
That being said, polymeric sand and jointing sand are not the only two options for a jointing compound. There are other joint sand alternatives on the market that are worth researching and deciding whether or not they will work for your application.