The world of decorative concrete has grown tremendously over the past decade. The innovations and new products have allowed the market to expand to areas very few expected. One area that has developed in both craftsmanship and innovation is concrete steps. Although dressing up stairs has been around for some time, new tools and techniques allow both novice and experienced contractors to differentiate themselves, and most importantly, increase their bottom line. Decorative concrete stair methods can be broken out into decorative formliners, strip and face, and decorative overlays. These methods are unique and have the ability to create an attractive focal point.
The step formliner is the most user-friendly and innovative way to create natural looking decorative concrete stairs. Foam formliners have been around for a while, but a newer method of using urethane liners has taken a giant leap over the past few years.
Several different options are now available, but the most prevalent is using a bull nose or cut stone liner in the face of the stair risers. Step formliners make the process a bit easier as they don’t require you to strip the forms the same day as pouring and they do not require the standard 28-day cure time when dealing with overlays. Another key advantage with step formliners is they can be easily used with radius stairs. Formliners require a bit of extra forming but nothing too extraordinary. Step liners come in many shapes and sizes but are most commonly used to create a cantilevered step along with a textured riser. Some manufacturers also offer a cantilevered option built into the liner to ease the process. Also available are riser liners to use under the cantilevered portion of the stairs.
Often the stairs are poured with the liners, vibrated, and cured overnight. Once stripped, the next day contractors will use release agents, stains, and color hardeners to accent the textured areas. The nice thing about formliners is they work seamlessly with radius steps, create a very natural stone or slate look, and add minimal additional costs.
Strip and face
Strip and face is the most common method of creating decorative concrete stairs and has been around for the longest period of time. It also is the same method that is used in nondecorative applications. This method usually is performed immediately after the concrete has set enough so the riser forms can be removed without damaging the formed concrete. This is commonly practiced with stairs and is performed to ensure there are no bug holes or honey combing in the face of the risers.
The forms are carefully removed once they are stable enough not to cause any sag. Then the stairs are rubbed out with a rubber float, magnesium float or trowel. Sometimes the contractor may add a decorative finish by leaving a swirl finish or just a rough finish with the float. This is the same method that has been used by decorative concrete contactors for years to create decorative stairs.
Once the stair forms are removed he uses color hardener to color both the tread and the risers with a float. Often the contractor will sift out some of the larger aggregate from the color hardener before beginning the application.
Once colored, a release agent is applied to both tread and riser, and a textured stamp creates a natural looking stone or slate. Some contractors wait until the next day to remove the forms, apply a bonding agent to the surface and follow the same procedures using color hardeners and releases to create a natural pattern on the stairs.
Also, some manufacturers make color hardeners to match their integral color systems. The advantage: Concrete can be poured with integral color and the matching color hardener colors the front of the risers once the forms are stripped.
Polymer-modified, cement-based overlays create a colored, textured surface. Two main types of overlays create decorative stairs: spray overlay and stamp overlay. Several manufacturers make both types and with most, the concrete must be fully cured before application.
The spray overlay is used with a hopper gun to create a splatter or knockdown finish. Most of the spray overlays can be colored, stained, and used with stencils to create a decorative look. With the stamp overlay a color complements the decorative nature of the existing concrete and is then applied to both the tread and the riser. A release agent and stamp are then used to create the desired look.
Keith Boudart is sales manager with Butterfield Color Inc. Visit www.butterfieldcolor.com. Visit www.concretesurfacesmag.com to view video of Butterfield Color’s Contractor Clinic presentation at World of Concrete.