Enhance Food and Personnel Safety by Promptly Repairing Floor Cracks in Food and Beverage Facilities

A small crack in a floor can be easy to ignore. But if left to wander and explore, it will grow more and more.That’s the inherent danger in not promptly addressing cracks in seamless industrial flooring systems — especially those found in challenging operating environments. What may start out as a hairline crack can quickly expand and spread due to foot and vehicle traffic, as well as cleaning protocols and other exposures.

Even before it expands, but especially after, a crack can create a sanitation concern in food processing areas, as it may become a harborage point for bacteria that prevents germs from being sanitized during cleanings. A crack in a distribution warehouse floor may become a catching point for trips and falls, expanding each time a worker’s toe or forklift inadvertently clips its edge.

Whether they’re a potential source of contamination or a safety concern, cracks in resinous flooring systems are fortunately relatively easy to repair in food and beverage facilities. However, installers need to follow particular procedures depending on the type of crack that needs repaired. For example, they’ll need to understand whether the crack is active (a dynamic crack) or stationary (a static crack), and they’ll need to know what crack filler materials to use to ensure compatibility with the existing flooring system. This paper offers some guidance on how to make the best repairs possible to enhance both food and personnel safety.

The Hazard of Cracks

Cracks in seamless resinous flooring systems may occur anywhere throughout food and beverage facilities, but they’re most found in areas subject to frequent stresses from traffic, equipment, cleanings and environmental conditions. Crack-causing traffic may include rolling carts in processing and packaging areas; forklifts in warehouses; and even general pedestrian activities in hallways, break rooms, and lobbies. Loading docks are especially prone to flooring cracks as tow motors move loaded pallets on and off trailers. In addition, areas around heavy equipment that vibrates have a higher likelihood of cracking, particularly at attachment points.

Cleanings may involve the use of harsh disinfectants that wear away incompatible flooring materials, hot water and steam cleanings that create thermal shock conditions, or even ultraviolet exposures that kill germs yet degrade certain types of flooring. Each treatment can run the risk of deteriorating flooring materials to the point that cracks will develop and then expand if not mitigated. Similar conditions may occur in chemical storage areas where spilled substances may weaken the floor.

Flooring cracks caused by environmental conditions are commonly found in cold storage areas, as well as any area subject to constant thermal cycling. For example, transition zones and thresholds between ambient temperature areas and refrigerators and freezers are a common place for cracks to occur.

In any of these places, a crack can pose a trip/fall hazard for employees, leading to potential lost time injuries and insurance claims. Each time a small crack is bumped, it may open wider and become a hangup spot for those trips. As wheeled traffic pivots on those weak spots, the flooring will deteriorate even more, causing an even greater hazard. An ignored crack can potentially spread to the point that a simple repair is no longer feasible. In such cases, those larger repairs could have been avoided if the smaller initial crack had been repaired promptly.

From a food safety perspective, cracks in processing and  production areas can be especially troublesome. Once fluids breach even a hairline crack, it can be difficult, if not impossible, to ensure those areas are properly sanitized with cleaning procedures. The small lip under a crack may be just enough room for various bacteria to hide and be missed during cleanings. And as that lip continues to grow, there will be even more room for bacteria to harbor and proliferate between the concrete substrate and lower layer of delaminated flooring. Eventually, sanitation procedures may become a losing battle around that crack.

How To Prevent Cracks

With safety at stake — and potentially the bottom line if a contamination event or injury were to occur — it’s best to repair any crack in a resinous flooring system as soon as possible. It’s also important to do everything possible to minimize the potential for cracks to develop in that system in the first place. That starts with the concrete pour, as any cracks in that surface have the potential to telegraph upwards to the flooring system installed on top.

Minimizing cracks in new concrete is the responsibility of the contractor, who needs to focus on preparation and proper curing. That means ensuring the subgrade is well compacted, that there’s a low ratio of water to cement and that proper reinforcements are used as needed. This person also needs to follow a variety of other best practices, including properly placing control and expansion joints. Ideally, the concrete should be left to cure for 30 days or more to identify any early crack formation before installing flooring. However, in many cases, that wait time isn’t feasible. In such cases, a variety of specialized coatings that are compatible with green concrete can be used within a flooring system to overcome any continued movement of the slab as it fully cures.

Of note, the American Concrete Institute (ACI) recommends that industrial floor joints not be filled for 60 to 90 days after a floor slab pour, or at least as long as possible. Its guidelines note that this delay is helpful to allow control and construction joints time to open closer to their ultimate width through the concrete shrinkage process. For freezer and cooler areas, the Institute also notes that the floor should be stabilized at its ultimate operating temperature for seven days prior to installation. The same suggestions are in place for treating cracks.

When the time comes to install the resinous flooring system, cracks will be far less likely to occur in the flooring if the building was acclimated to in-use conditions. That means the building was fully enclosed with the HVAC system running, allowing concrete and building materials to dry and shrink or expand as they would in everyday operations. Waiting until that time is the easiest way to avoid excessive cracking in flooring systems.

Naturally, installing flooring under an ideal time frame isn’t always possible. In those cases, and even in ideal ones, facility mangers, flooring suppliers and installers should collaborate on the most appropriate systems to use given the area of the plant and the anticipated exposures that flooring will encounter. Planning ahead will allow everyone to consider installing specialized layers such as membrane crack fillers, which are designed to bridge small cracks in the concrete so the flooring over top won’t face the potential shearing forces of a crack moving from below. Installers may also be able to consider installing a flooring system everywhere except at joints and then fill in those sections later — after the building is acclimated — so the flooring system won’t have a chance to crack initially and then will not be isolated from the joint when it’s filled in.

Despite the best precautions against them, cracks may eventually form in any flooring system. When they do, installers can engage in the repair protocols that follow.

Concrete cracks may occur anywhere throughout food and beverage facilities and should be addressed using the proper repair techniques depending on the type of crack that exists.

Areas around heavy equipment that vibrates are prone to cracking, particularly at and near attachment points.

It’s important for food and beverage processing facilities to promptly repair cracks to eliminate bacteria harborage points and enhance food safety.

Any one of the previous types of dynamic cracks could indicate a structural problem with the building’s design. Therefore, it is highly important for facility managers and repair technicians to determine the root cause of a dynamic crack before repairing it. For example, if the crack shows active movement or visible heaving, they’ll need to consult a structural engineer first before attempting repairs. Otherwise, any repairs may be likely to fail.

To properly repair a dynamic crack, remember that forces will continue to work on the flooring material that covers the crack. Therefore, repair technicians need to plan for that movement. The recommended approach is to make a sawcut through the finished flooring system and then only fill that void in on the two sides — and not the bottom — to achieve two-point adhesion (Figure 1). The cut should be to a depth of 3/4-inch deep and a minimum width of 1/4-inch using a diamond blade saw attached to a vacuum to minimize dust entering the notch. This notch width ensures there will be sufficient surface area available for the flooring system patch to form a strong bond to the concrete.

To prevent three-point adhesion, installers should then force a bond breaker, such as a closed-cell backer rod, into the cut notch. This backer rod should be 1/8-inch wider than the notch to prevent the resinous flooring material that will be applied on top from sneaking by the rod and adhering to the bottom of the notch. This bond prevention is critical because as the dynamic crack moves, the backer rod allows room for movement of the flooring material downward within the notch, rather than pushing everything upward and causing the repair to crack.

Figure 1. Best practices for repairing dynamic cracks include cutting a minimum 1/4" wide by 3/4" deep notch through the finished flooring system and concrete before adding a backer rod and applying flexible joint material on top. The backer rod prevents three-point adhesion, allowing the repair material to move downward with expansion, rather upward where it may cause a repair to crack.