Photo courtesy of Colorado Hardscapes Inc.
The Sandscape Texture system manufactured and sold by Bomanite is a happy union of utility and beauty. Its usefulness lies in its slip resistance and high durability. Its beauty lies in its consistency and attractive color possibilities.
The finished surface, which resembles sandblasted concrete, is achieved by applying a specialized surface retarder on top of a mix optimized for planned sand exposure. Then, the top 1/32 inch to 1/16 inch is removed. The result is uniform sand exposure with a texture that is consistent no matter how large the area.
This sand is also the key to the product's durability. In a broom finish, the paste layer is relatively fragile and prone to show wear, explains Terry Grimble, Bomanite director of technical services. Exposed sand, in contrast, stands up to traffic without showing wear patterns, so the finish remains consistent and fresh-looking.
Bomanite works with its network of qualified contractors to come up with just the right Sandscape mix design for a given project and locale. Each mix carefully balances colored sands with larger aggregates that can be depressed so only sand rises to the surface. Some native sands won't work, Grimble warns, because they contain particles that are too coarse. And some aggregates are lighter than sand, so they will not stay down. So, for example, in locations where limestone aggregates are common, Bomanite imports heavier aggregates like granite or basalt.
Since so much sand is exposed, the color of the local sand determines the finished appearance, so Grimble strongly recommends creating samples with a mix that contains the local materials to be used on the job. When color is added, a color should be selected that will complement the sand.
Sandscape derives most of its color from the sands exposed as part of the process. This finish may have less color intensity than finishes for which the surface paste is not removed. To achieve a better-defined color, a contractor might want to increase the volume of colorant added to the concrete. Chemical stains and lithium silicate color systems can also be used. The Sandscape system is very receptive to color because the small grains of sand present so much area for color to settle around, Grimble explains.
To maintain a natural look, Bomanite recommends using a penetrating sealer to close the pores so the concrete will resist stains. A water-based matte finish sealer locks in the color and adds stain protection.
Consistency, durability and slip resistance make Sandscape a desirable surface for plazas, walkways, shopping centers and schools, according to the Bomanite website.