Vice President, Flowcrete
The surest way to avoid resin floor failure is to take the necessary steps at material specification stage to prevent the problem from occurring in the first place by selecting fit-for-purpose, durable floor systems that have been designed to meet the operational demands of the individual environment alongside any health, safety, hygiene, and compliance regulations specific to that industry.
Some of the most common mistakes that should be avoided during the specification stage include choosing a finish based only on its visuals, picking the cheapest option, simply using the same system as before, and paying little attention to the substrate or the practicalities of the site’s future use. Falling into any one of these traps could result in the application of an inadequate floor that will crack, crumble and fail when faced with the site’s day-to-day demands.
The demands placed upon the floor surface or the resilience of the material itself is often underestimated until it is too late. Understanding the reasons or triggers that can lead to floor failure can help prevent such instances from ever occurring.
Despite the durability of resin flooring, it is vitally important to take a number of factors into account to ensure a long lasting and high performance finish. This is especially true in industrial settings, where the floor will have to withstand chemical abuse from a variety of substances including water, dust, fuels, sanitizers, acids, lubricants, and in certain industries, by-products from foodstuffs including sugars, hot oils, blood and grease. If left unchecked, chemical attack can degrade not only the finish but can eat into the concrete substrate and affect the soil underneath.
The temperature of the chemical contaminants or harmful substances will need to be considered. For example, grease is fairly inert at room temperature but highly corrosive when heated to high temperatures.
On top of this, the nature of exposure to which the floor will be subjected is also important. This is typically categorised into three degrees; immersion, intermittent spillage or infrequent contact. A full risk audit should provide an idea as to how many chemicals or corrosive substances a floor is likely to come into contact with throughout its lifetime.
On top of this, floors are subject to mechanical abuse from equipment being moved, tools being dropped, pallets dragged across the surface, as well as rubber and steel-wheeled forklift traffic.
The compressive strength of the floor system can be used to determine the suitability of the floor to the task at hand. Going back to the hand pallet truck scenario, a compressive strength of at least 40-50 N/mm2 would be required.
In addition, factories have to undergo punishing clean and wash down processes that can involve very hot water or even steam in order to remove fuels, grease and other chemical contaminants. However, the majority of plants operate at ambient room temperatures and therefore, during cleaning and wash down processes, become subject to thermal shock as the floor is suddenly exposed to temperatures in excess of 180 degrees centigrade.
Hard floors based on epoxy, vinyl ester or MMA chemistry are not equipped to deal with thermal shock conditions, and as a result, can crack or delaminate when exposed to extreme temperature swings, weakening the surface and invariably leading to the early onset of floor failure.
Thermal cycling can also be problematic, this is when the temperature is slowly or seasonally lowered or raised due to climatic or service conditions as well as periodic cleaning programmes. Again, inadequately this process could irreparably damage materials.
Getting the concrete slab or underlying substrate right is critical to an effective floor finish. Poor substrate preparation is one of the leading causes of delamination, which will occur if the concrete is too smooth, if the laitance has not been removed or if there is otherwise a substance or reason that the resin coating can not effectively bond to the substrate.
The substrate’s pH levels and moisture content can wreak havoc on the floor if not addressed at the material specification stage. Concrete is, to some degree, permeable and will absorb moisture from the ground, particularly if it is low grade or located close to high water table, and in addition to this, new concrete typically has a very high moisture content until it fully dries out. This means that the substrate’s moisture level should be thoroughly analysed during the specification stage, and if the cyclical moisture levels are too high, then a damp-proof membrane (DPM) should be applied.
A DPM works by smoothing out the transition of moisture vapour through the floor; without this the moisture would rise up unevenly and cause blistering or de-bonding in the resin finish.
Synthetic resin flooring is available in a wide range of thicknesses, from thin floor sealers to heavy-duty industrial protection.The resulting flooring can provide a seamless surface with greatly enhanced performance compared to the concrete base on which it is typically applied.
The best resin flooring systems today, are primarily based on three different types of two-part (also called two-component) synthetic resins. These are: two-part epoxy resin flooring systems, two-part polyurethane resin flooring systems, and two-part acrylic resin flooring systems (also called MMA resin flooring). Other specialist chemistries available include vinyl ester, polyaspartic and Novolac resins.
There are water-based, solvent-based and solvent-free types of all of these different synthetic resin flooring materials. All have their own characteristic advantages and disadvantages in both application and their performance. In general terms, all resin flooring is fast curing or hardening as well as tough and abrasion resistant. All tend to produce hardwearing resin floor finishes that are chemical resistant, impermeable to liquids, hygienic and easy to clean, as well as provide a strong permanent bond to the concrete slab.
However, there are great differences between the different types of resin flooring materials and different resin floor product formulations on the market. The following paragraphs outline in basic terms which materials are the best fit for various situations.
Starting at the thinner end of the scale are water-based epoxies of up to 300 microns that are typically utilised in light to medium warehousing. These will provide excellent dustproofing qualities, and are a cost effective alternative to traditional flooring materials in areas not subjected to rigorous service conditions. These types of solutions have a practical life of two to three years and can also be used as a hygienic wall coating.
Higher build coatings of 300-1000 microns are ideal for use in plant rooms thanks to the excellent abrasion and chemical resistance properties they provide. Quartz aggregates can be incorporated into the finish to create a slip-resistant surface, which is especially useful in areas prone to wet working conditions. The practical life of such systems is three to five years.
Next on the scale are 4-6 mm thick trowel applied epoxies. These will ensure a better level of impact resistance and are ideal for heavy industry areas that will place a lot of demands on the floor. These systems can be specified in a decorative, multi-coloured finish and can be expected to last up to ten years in situ.
Finally, there are seamless terrazzo systems, which can be in either epoxy or polyurethane formulations. These can be applied in intricate patterns and can even have sparkling aggregates incorporated into the finish to create a stylish visual effect. This type of flooring material is very easy to clean and maintain and can be expected to last for twenty-five years if properly maintained.
During the specification process, the architects, designers and facility operators should consider what extra benefits can be added into the finish. For example, considering the finish in terms of risk management is critical in wet service areas, as is ensuring the flooring system is tested under these conditions to determine if it will provide the correct level of safety.
In wet service environments, it is essential that flooring is laid to falls so that excess liquid flows towards the drainage system in order to prevent the pooling of water and lessen the risk of slips.
Resin flooring is available in a range of textures and can be graded with broadcast aggregates to increase its anti-slip profile. It is important to note that coarsely textured surfaces are more difficult to clean than smoother finishes, therefore a compromise may need to be made where heavy slip resistance and ease of cleaning are both of critical importance.
Another useful way to tailor resin flooring, particularly for contamination sensitive environments, is to include anti-bacterial additives into the finish. This can be achieved in a number of ways, for example, Flowcrete’s Flowfresh range has the silver-ion agent Polygiene® homogenously distributed into the floor’s resin matrix.
Unlike industry standard flooring solutions, such as standard polyurethane concrete or polypropylene, Flowfresh has been scientifically proven to inhibit antimicrobial growth on the surface of the floor by up to 99.9%. Its effectiveness meets both the ISO 22196 and JIS 222801 standards for measuring a surface’s anti-bacterial effectiveness.
When deciding which floor is right for your facility, it is important to discuss all the relevant factors with both a supplier and applicator that have experience creating floors in similar situations. It is also advisable to visit other facilities to see how different types of floors have stood up to comparable conditions, and if possible, install a sample within your facility to put it through its paces before committing to a complete coating.