When its time to pave or repave your walkway or patio, it is important to choose quality pavers that hold up to weather and foot traffic. Just as important as choosing the pavers, however, is choosing the material that sits beneath and supports the weight of the pavers. The base and setting bed of a walkway or patio needs to compact properly and drain well to prevent settling and keep the surface level. Rock dust and sand are two common bedding options for pavers.
Also called rock dust, stone dust is more prone than sand to settling and drainage problems when used as a base beneath walkway or patio pavers. Stone dust has a powdery texture because it results from stones being crushed. A proper base material can be compacted easily; however, due to stone dust's powdery nature, it does not compact as well as other materials. It also drains poorly, which is a problem in climates that receive a high amount of rainfall. Although problems may not present themselves right away, pavers are more likely to experience settling and shifting when they are supported by stone dust instead of another material.
Not all kinds of stone dust are poor choices for pavers, however. Crusher run, also called processed gravel, is a rock or stone dust made of particles about the size of a grain of sand. It is coarse, rather than powdery, giving it properties that make it superior to regular stone dust, reports Nimvo. Crusher run is a highly compacting, well-draining material that is second only to sand as a base for pavers. It compacts tightly, forming a base that can be walked on without harming the bedding surface.
Many kinds of sand exist, but only a few kinds are suitable to use as a bedding material for pavers. Kinds of sand that are unsuitable for paver bases include all-purpose sand and varieties made for children's sandboxes. Masonry sand and limestone screenings are also poor choices because they are too fine and cause problems similar to those of powdery rock or stone dust. Concrete sand, also called bedding sand, is the proper choice for a base when setting pavers, reveals Braen Stone. That kind of sand is coarser than other varieties.
Concrete sand's coarse texture prevents problems with drainage and creates friction that helps lock pavers into place. It compacts easily by hand or with the use of a mechanical compactor. As it is compacted, the sand rises into the joints between the pavers, helping to hold the pavers in place. That factor also helps with drainage and prevents moisture from getting underneath pavers. Sand also allows flexibility of the ground and keeps the pavers from cracking or settling under pressure if the ground shifts.Get in Touch with Mechanic