Jointing Sand for Clay Pavers

Sand Type

• Coarse river-washed and concrete sand are typical jointing sand types. Both of these sands have sharp angles on the grains. In fact, their size should not exceed 3/16 inches. You need multisized sand grains within a joint so they can slide together to remove large air pockets. A properly installed paver project should not allow rainwater to percolate into the joints or cause sand to wash away with water runoff. Sand with uniform grains, such as sandbox types, quickly erodes away because they cannot lock together.

Interlocking Science

• Jointing sand is commonly swept into paver crevices and then compacted with a plate compactor machine. Your compactor should have a rubber mat attached to protect the clay pavers from damage; concrete pavers easily withstand the machine's action. As the machine moves across the pavers, sand slowly vibrates into a locked position. Aside from reducing paver chipping between pieces, small sand grains insulate larger grains from eroding during the compaction process. As the sand settles, however, your joints require more sand. A typical installation demands several sand layers swept into the joints along with multiple plate compactor passes. Your joints are properly installed when sand fills the entire space.

Paver Spacing

• For the best jointing action, space your pavers between 1/16 and 3/16 inch away from one another. Any larger spacing prevents proper sand locking. For example, you fill a 1/4-inch-wide joint space with sand, but foot traffic quickly cracks the clay pavers. Specific paver spacing allows weight loads to distribute evenly across the walkway or patio. You can even add some fine sand into properly spaced joints after compacting multisized grains to their normal height. Adding fine sand fills any remaining joint crevices to impede damage over time.

Considering Setting Bed

• Your jointing sand also meets up with the sand setting bed during paver installation. Commonly installed on a 4-inch gravel bed, setting beds range between 1 and 1 1/2 inches thick. This layer provides a level surface for your pavers. If the bed is not level, your walkway reflects the contours once pavers are compacted into the sand. As you use the plate compactor, your pavers move approximately 1/4 inch into the setting bed, forcing some of that sand to move into the joints. Your jointing sand should easily mix and compact with the bed sand if the grains are multisized. Improper jointing sand mixtures will not combine with the setting bed, creating a joint space that reduces paver resilience to weight loads.