Selecting and maintaining textured floors

Most people don't give floor surfaces much thought until a problem appears. For instance, personnel safety and potential liability may become issues only when floors become slippery under normal operating conditions. Often, a "wet" environment is considered wet only because it requires frequent cleaning to maintain a hygienic environment. Maintaining floors properly to prevent hazardous conditions in kitchens, restrooms, production environments and public lobbies depends on the type of flooring system and the conditions of use. Typically, textured seamless floors are specified if exposure to water, oils, greases or other process materials is a common event. Selecting the right flooring is smart, but it's equally important to develop standard operating procedures for cleaning the floor.

Weighing the conditions

Food processing represents an aggressive environment for flooring. So the flooring systems must withstand chemical attack and abrasion, as well as provide a safe, slip-resistant surface. Bare concrete won't stand up to acid and becomes slippery when fats, oils and water spill on it, so textured flooring is common in these areas.

Resurfacing systems that use 1/4 inch of urethane can withstand the physical and chemical exposures and the thermal shock from steam cleaning. These systems can be finished with a non-slip surface to provide safe walking under almost any condition.

Heavy manufacturing and assembly plants must also address the issue of slip resistance because their floors are exposed to oils and particulate matter. The flooring also must withstand traffic and abrasion. Combining proper floor texture and maintenance procedures minimizes slip hazards in these facilities.

Wet and soiled conditions with low foot traffic are characteristic of commercial kitchens and plant cafeterias. These areas don't undergo the same degree of abuse and steam cleaning as food processing facilities, but slip resistance and a clean environment are equally important. In these situations, a decorative seamless floor, such as a quartz broadcast or a decorative troweled system, is most frequently selected. These systems also typically receive a textured finish to ensure safety.

Lobbies and restrooms are mostly dry with light traffic, although seasonal wet conditions occur, so flooring for these areas is generally selected on the basis of aesthetics. Since light foot traffic and routine cleaning in these areas don't dictate a need for textured floors, terrazzo, marble and tile using an ADA-compliant sealer maintain the desired non-slip surface. Table 1 summarizes exposures, cleaning requirements and texture considerations for these various plant areas.

Marrying texture with safety

A seamless floor can be textured in several ways. The topcoat applied to a flooring system may contribute to the slip resistance, especially if the coating provides a stipple finish. A satin finish features microscopic surface irregularities that can provide slip resistance. Smooth flooring finishes, especially epoxy coatings, tend to abrade over time, which increases slip resistance characteristics.

For more aggressive environments, texture is built into the floor using aggregates. Light service areas can use polypropylene beads to yield a slight texture. Kitchens and shower rooms frequently have colored quartz, broadcast floors, which contain a natural texture based upon the installation procedure. The texture on an aggressive quartz broadcast floor uses a single, thin coat of polyurethane that "follows" the profile. Application of grout coats and topcoats of clear epoxy or urethane actually diminish floor texture. A 100% solid, zero volatile organic content epoxy topcoat "fills" the profile and can reduce the texture.

Heavy manufacturing conditions require a more durable texture that will not be crushed due to the traffic of forklifts and other vehicles. Silica sand is incorporated into the finish surface of slurry/broadcast floors and 1/4 inch trowel applied resurfacing systems for slip resistance. Varying the size of the aggregate also impacts the degree of slip resistance. Larger aggregates, such as a 30-mesh silica sand, provide more slip resistance on a dry surface than the smaller size 40-60 mesh silica.

Wen-Ruey Chang and Associates at the Liberty Mutual Research Center for Safety and Health have studied the role of surface roughness in floors and footwear. They concluded that the combination of the microscopic roughness of the sole and the floor surface affect the coefficient of friction significantly. This principle helps to explain the extreme variances obtained when various waxes and sealers are used on textured floors. It's important to ensure that ADA-compliant sealers and maintenance materials are used in lobbies and restrooms, where a noticeable, macroscopic surface texture is absent.

In our research, the ASM 725 Slip Meter (American Slip Meter, Inc.) was used to measure the static COF of various dry industrial flooring systems with smooth and textured surfaces. The meter determines the force necessary to initiate movement of a weight. Two different grades of aggregate were used, a 40/60 mesh silica sand and a more aggressive 30 mesh silica sand. Results indicated that a smooth surface complies with ADA 0.5 COF recommendations in dry conditions, but the addition of texture to the flooring system dramatically increased the COF for both leather and Neolite (rubber) soles. The 30-mesh aggregate improved slip resistance as represented by an increased COF (see Figure 1).