Concrete Floors - Factors To Consider When Selecting A Flooring System
Heavy Fork Lift Traffic
The specified system must withstand high abrasion from rolling loads. Generally, thicker systems (1/8") or greater are used to provide sufficient wear resistance and protect against impact when forks or the forklift load is dropped.
Maintenance of clean surfaces is critical in certain areas. A delicate balance must be struck between cleanability and slip protection, especially in wet areas. In addition, selected systems should resist both the mechanical and chemical demands of the cleaning operation. Working closely with the specifier, manufacturer and installing contractor will help insure cleanable systems are installed. It is a good idea to have a sign off on submitted samples to create a standard of performance or, better yet, sign off on (or approve) a project mock up prior to installation of the entire area.
As detailed above, needs for clean-ability and safety dictate required surface profile. Typically, for more aggressive requirements, aggregates are incorporated into the resinous floor system. The size, shape, and type of slip-resistant additive is determined by the environment the floor is exposed to. The degree to which these aggregates are covered or encapsulated impacts how aggressively they protect against slips and falls. Often overlooked, Slip resistance is an important system attribute to help insure worker safety. Accidents attributed to slips and falls cost employers millions annually in lost time and lawsuits.
Both process and cleaning chemicals present challenges to resinous protection systems. Temperature, length of exposure (time), concentration, maintenance routine, and potential for chemicals to mix with other chemicals are all necessary pieces of information. With this information, the material manufacturer can recommend the proper protective system.
Heavy Foot Traffic
Foot traffic can be aggressive from an abrasion standpoint if abrasive dirt is present in an area. Thin mil coating systems (< 10 mils) may not provide sufficient long-term protection. Ability to recoat these areas must be considered. If the area has extremely limited access, a high build (15 mils or greater) should be used.
Vibration From Machinery
This condition may lead to cracking or delamination of resinous floors. If isolation pads are not possible, flexible systems can be utilized. Today, non-externally flexible epoxy systems represent the state-of-the-art to address these situations.
Heavy Steel Wheel Traffic
Steel filled epoxy systems will withstand this condition quite well. Available in 1/4" thick systems, they also withstand point loading and heavy impact.
Collection of chemicals to segregation and re-use or treatment requires protection of the substrate. Typically the resinous protection system must withstand a minimum 72 hour exposure to the chemical in question. The same information required for 'harsh chemicals' above must be gathered for a manufacturer to make a specific recommendation.
USDA / FDA
Federal regulations require that resinous system manufacturers exclude certain chemicals from their product formulations. A phone call to the resinous system supplier is typically all that is necessary to ascertain their compliance with these regulations.
Conductivity / Static Control
These systems are used where a potential explosion or fire hazard exists (in the case of conductive systems) or, the potential for damage to sensitive electronic equipment or components is present (static control).
When a spill of hot material occurs on a resinous floor or wall system, the system must be capable of withstanding the heat exposure without complete degeneration of its physical properties. Also, different liquids dissipate their heat at different rates (for example grease versus water). Most epoxies will withstand intermittent temperature exposures of 120°F. Hybrid systems are available for exposures up to 500°F.
This attribute should not be overlooked. What the resinous system looks like upon completion, and its appearance 6 months, one year and 5 years from now, given current and anticipated operating conditions and maintenance may be important. Because certain resinous systems are many times more abrasion resistant than concrete, it is possible to select systems that retain their aesthetics even in the face of tough operating conditions. The impact of clean facilities on employee morale and potential customers is obvious.
Often areas with high lighting or poorly lit areas can be significantly brightened through the use of light colored resinous protection systems. Initial gloss levels can be specified for resinous systems. Also, gloss and color retention information can be secured from the manufacturer.
Resistance to impact protects the substrate from damage from dropping or falling objects. Generally, troweled 1/4" toppings have been used for these applications and have performed fairly well. A new technology, based on a flexible epoxy binder resin has displayed superior performance.
Epoxy systems are available with integral biostats. It is important to verify that the manufacturer's claim for both the biostat and finished epoxy system are substantiated.
Timing and scheduling of the installation may impact your system selection. There are some chemistries available which allow for quick installs, while other polymers may require cure times of up to one week in order to provide full chemical resistance. Most epoxy and urethane systems require the concrete to be at least twenty-eight day old because these systems will not allow the excess moisture to escape from the concrete. Considerations must also be give to work schedules of existing facilities and other trades in new construction.
Some of the fastest setting polymers are methylmethacrylate (MMA), novolac epoxy, vinyl ester and polyurea. Each of these chemistries provides unique advantages but may have other drawbacks. MMA, for example, has a strong odor, is sensitive to water terminating the reaction, and is higher in cost. Similar to MMA, vinyl esters use a free radical reaction, which is sensitive to water, and have a pungent odor. Polyurea exhibits excellent elongation but in general has lower adhesion properties relative to epoxy. Novolac polymers have a high degree of cross linking which gives them excellent chemical resistance but does not achieve full chemical resistance for 7 days and will have a tendency to chalk and discolor when exposed to UV light. Given these shortcomings, sometimes scheduling of an installation requires the use of fast cure materials.