In 2011, brothers Eric and Ryan Jensen inadvertently killed 33 people nationwide. The dirty, hard-to-clean floors in their packing house contaminated the Colorado farmers’ cantaloupe with listeria bacteria. Almost 150 other people were hospitalized.
The tragic incident wouldn’t have happened if they’d used an internationally accepted, 12-step process designed to prevent foodborne illnesses: the Hazard Analysis and Critical Control Point (HACCP) management system. Developed in the U.S. in the 1960s to protect astronauts, the system can be used to create safety plans mandated by the Food Safety Modernization Act of 2010.
Since then, the automotive, aviation, chemical, cosmetics, and pharmaceutical industries have begun using the system to design, build, and maintain their manufacturing facilities. Along with food and beverage processors and manufacturers, these companies represent a significant market for contractors who specialize in concrete surfaces.
Concrete's the right floor IF...
Food and beverage processing and manufacturing facility floors are exposed to seriously heavy doses of corrosive fats, hot oils, blood, sugar solutions, and natural acids. These organic substances breed bacteria, fungi, mold, and mildew when they settle in joints, grout lines, gaps, and cracks. To keep that from happening, floors are constantly steam-cleaned and/or pressure-washed with aggressive agents.
You can see why HACCP requires a seamless and impervious floor at all times. With the proper surface treatment, concrete meets both criteria.
However, fats, oils, and grease can infiltrate concrete, resulting in microbial growth and the spread of bacteria that could contaminate products. Rigorous maintenance can exacerbate the problem by making the concrete more porous.
Therefore, slabs should be covered with a high-performance flooring system that remains non-absorbent and easy to clean for a long time.
Thermoplastic coverings, terrazzo, epoxy resins, and cementitious urethane all provide seamless finishes, but only one meets all HACCP criteria.
In fact, according to this Liquid Floors blog, cementitious urethane was formulated specifically for the food and beverage industry. Like epoxies, it’s made by combining two liquids. Unlike epoxy coatings, it’s also made with Portland cement.
The resulting mixture expands and contracts at the same rate of concrete to resist bending, buckling, and cracking; and withstands temperatures from -330 to 240 degrees F.
In general, the thicker the system, the longer the service life. The greater the potential for damage, the greater the need to protect the critical bond layer where the coating meets the concrete.
Traffic loads in particular should be considered. A full hand pallet truck, for example, weighs more than a ton. The small wheels exert a lot of pressure on the floor, especially in areas with tight turns. Compressive strength of 5,802 psi to 7,252 psi is required.
A cementitious urethane finish 6 mm to 9 mm thick dissipates the impact and, should a chip occur, keeps the defect from traveling down to the substrate.
Impact on drainage
To facilitate cleaning, HACCP also requires adequate drainage. Stainless steel is easy to clean, so the floor will probably have stainless steel drains.
Stainless steel, however, has a different coefficient of movement than the coating. When the temperature fluctuates, the two materials will struggle to expand and contract next to each other.
To keep cracks from forming along the edge of the drainage channel, Dave McNeece, managing director of Flowcrete Americas in Spring, Texas, recommends installing an expansion joint on either side of the drain. The company’s Flowfresh products were certified by HACCP International in July 2015. Impregnated with a silver ion-based bactericidal additive developed by Swedish company Polygiene AB, the product line is believed to be the only antimicrobial cementitious urethane to be HACCP-certified.
So, to recap: When working with clients to design a floor according to core HACCP principles of seamlessness, imperviousness, cleanliness, and drainage, factor in how the flooring system will work with surrounding building materials such as drains and where the floor meets the wall, as well as the how the facility’s use will impact the coating.