Concrete Finishes,
Brushed Concrete Finishes

A contractor can turn a brushed concrete finish into an inexpensive decoration that will please his client and boost his company’s reputation.

Brushes and broom heads made specifically for concrete finishing are made from several materials. “We have horsehair, polypropylene, styrene, and nylon bristle brushes in our catalog,” says Greta Moore, executive assistant at Magnolia Brush Manufacturers. She explains that horsehair, which is soft, gives the finest finish, while stiffer bristles give a coarser texture.

Horsehair, the traditional favorite, is still popular. “Overwhelmingly, the choice is the horsehair brooms,” says Jim Stormont, vice president of Marshalltown Co. In fact, Marshalltown’s horsehair brooms outsell their polyfiber brooms by roughly 200 to 1.

On the other hand, Gary Bolden, president of Marion Brush Manufacturing Co., says Marion makes only nylon bristle brushes. They achieve a softness similar to horsehair by using very fine bristles — as thin as 0.008 inch. “A lot of horsehairs and fiber materials will collect concrete and hold it at the ends in little balls, but the nylon doesn’t seem to do that nearly as bad,” Bolden says. His company uses only No. 612 Dupont nylon resin for its bristles. “It’s the most expensive nylon resin on the market,” Bolden says, “but we use it for its chemical and wear resistance, and its superior [shape] memory.”

Innovation
One way creative contractors can achieve unusual decorative finishes is by modifying stock implements. For example, in response to customer requests, Marion Brush has made custom brushes with variegated stiffness. A brush with alternating sections of stiff and medium bristles along its length creates an appealing pattern.

Another way to achieve unusual brush patterns is to use an unconventional applicator. For instance, Rick Smith, owner of Richard Smith Custom Concrete, reports using stainless steel brushes for extremely hard, rough surfaces. “I emphasize stainless,” Smith says, “because if a bristle was to come off of a standard steel brush, the bristle would typically rust and create a stain.”

Another great way to achieve a brushed finish is to use a sponge, says Chris Sullivan, national technical director for QC Construction. “As the concrete achieves a certain hardness, you start applying water to the surface with a hose, and use the sponge to work away some of the cream, to get the desired effect.” This requires a lot of work on the hands and knees, so it is expensive and time-consuming for large areas. However, Sullivan has seen the technique used effectively on small decorative areas such as pool copings, and accents or inlays within a concrete pad.

Another bristle-free brooming technique involves working a magnesium float in half circles.