Brooms for Concrete

The shallow, grooved texture left on the surface by a concrete broom or brush will help keep shoes and tires from slipping or skidding on a wet or icy slab.

There’s not much of a secret in how a concrete broom is used, either. For a “broom finish,” contractors pull a broom across the slab, preferably at a right angle to anticipated traffic. Less frequently, they swirl the broom for a “swirl finish,” which looks nicer but requires more work.

The broom’s bristles should be held at a 45-degree angle to the surface, says John Wight, vice president of sales at Bon Tool Co. The tool should be pulled with light pressure appropriate to the job. “It depends on how quickly the concrete is setting up,” he says.

But while brooming is as simple as sweeping, finishing brushes and brooms are not ordinary cleaning brooms. They have unique properties that make them specifically suited for putting a textured finish on a slab.

The bristles of concrete finishing brooms have more consistent lengths and shapes than those of ordinary brooms, says John Strawn, product manager at Marshalltown Co. Consistent bristles mean a more consistent finish, he says. “You’re actually texturing, not working to clean up the concrete.”

The connection between the broom and its handle can be different too. While a typical broom is attached to a handle that is fixed in place, a concrete broom may be bolted to its handle with a “clevis adapter” so it can be adjusted for pitch.

Finally, the typical bristles used in a concrete broom will be softer than those of a standard broom, although the coarsest concrete brooms can be rougher, Strawn says.

“With a finishing broom, you don’t want it too stiff,” says Robert Bower, marketing manager at Wagman Metal Products Inc. “You want to finish, but you don’t want to dig into the surface.”

Ordinary brooms are no substitute. The standard push broom is too stiff and has too much body to make a good finishing broom, says Gary Bolden, president of Marion Brush Manufacturing Co. There are five or six rows of bristle tufts on a push broom, compared to only two rows on a finishing brush, he says. “A lot of times a push broom exposes aggregate. It’s rougher than needed.”

A push broom will also be too heavy compared to a finishing broom. “It digs into the slab, and doesn’t make it as uniform or as level,” Bolden says.

What’s more, finishing brooms such as Marion Brush’s are designed to texture with the sides of bristles rather than the ends, Bolden says. “If you use the ends of the bristles on a slab, it pulls away the cream and exposes the aggregate.”

All about the bristle
There are differences within this niche market too. The most important characteristic of each concrete brush and broom is the bristle itself. “The bottom line is that the quality of bristle drives the quality of the broom,” says Strawn. “A strong, consistent bristle makes a great broom.”

Softer bristles are used when a contractor is getting on the floor sooner. Stiffer bristles are used for a rougher finish or when concrete has started to cure.

Contractors prize the aggressive texturing of a stiffer brush when slip resistance is more important than appearance, such as on a ramp. The stiffer the bristle, the rougher the surface, says Steve Cook, sales and marketing manager for Kraft Tool Co. “The contractor buys a broom based on the kind of finish he’s looking for,” he says.