What is a Flow Applied Flooring (Self-smoothing Floor)?
Flow applied flooring, commonly referred to as self-smoothing flooring, is a liquid-applied resin system that is poured onto a prepared substrate and allowed to self-smooth under the influence of gravity. The result is a seamless, continuous surface with a consistent thickness, free from grout lines, joints, or surface irregularities that could harbour bacteria, moisture, or debris.
Flow applied floors are formulated with carefully calibrated rheology (flow behaviour), meaning the material spreads itself across the floor to a flat, even plane with minimal intervention from the installer. A spike roller is typically used to release trapped air bubbles, while the smooth finish is achieved by the product itself. With Arturo flow applied resin floors, they can contain a de-gassing agent which allows floors to be installed without the need to spike roller, making them quicker and easier to install.
Key definition: A flow applied or self-smoothing floor is any liquid resin system, typically epoxy or polyurethane (PU), that create a smooth surface under gravity to create a seamless, hygienic, and durable finish across commercial, industrial or healthcare environments.
Arturo flow applied flooring systems are typically installed at a thickness between 2 to 3 mm, although some specialist formulations can be applied at up to 9mm. The two dominant chemistries used are epoxy resin and polyurethane (PU), each offering distinct performance advantages depending on the environment.
2 - 3 mm Typical application thickness
24hrs Light foot traffic cure time
10+ years Expected service life
The Flow Applied Application Process
The success of any flow applied resin flooring installation depends as much on the preparation phase as the product itself. Cutting corners during substrate preparation is the single most common cause of flooring failure, from delamination to surface bubbling. Here is a step-by-step breakdown of how a professional installation unfolds.
Substrate assessment & preparation
The concrete or existing floor substrate is inspected for moisture levels, surface contamination, cracks and compressive strength. A minimum compressive strength of 25N/mm2 typically required. Surface laitance, oil, grease, and existing coatings must be removed via shot blasting, diamond grinding, or scarifying to achieve the correct surface profile.
Moisture Testing
Relative humidity (RH) levels are measured using either surface hygrometers or in situ probes. Most of Arturo's epoxy and PU systems require RH below 75%. A damp-proof membrane (DPM) can be applied if readings are too high.
Priming
A primer coat is applied to seal the substrate, helping prevent absorption and improve the subsequent adhesion of the flow-applied floor. Arturo’s low-viscosity epoxy primers are most common. In porous substrates, a second primer coat may be required. The primer must fully cure before proceeding.
Mixing & pouring the Self-smoothing floor
The two-component resin system (base + hardener) is mixed on-site at the manufacturer's specified ratio, typically using a forced-action mixer or variable-speed drill with paddle attachment. The mixed material is poured in strips or sections across the primed surface and spread with a notched squeegee to achieve the desired depth.
Spike rolling
Unlike most flow-applied resin floors, Arturo’s contain a de-gassing agent, so they do not require spike rolling, saving the installer time and effort. With other manufacturers, within the product's pot life window, a spiked roller is passed across the wet surface in a cross-hatch pattern to release entrapped air bubbles and ensure uniform thickness. If done too late, the material begins to gel and spike rolling will leave permanent marks.
Curing & optional top coat
The floor is left to cure. Most systems are trafficable after 16 to 18 hours and reach full chemical cure in 5 - 7 days at 20°C. In cold conditions, cure times extend significantly. An Arturo UV-stable polyurethane top coat is often applied over PU resin floors to improve scratch resistance and prevent discolouration from UV exposure. For epoxy resin floors, an optional coloured top coat can also be applied to achieve the desired colour aesthetic.
Pro tip: Temperature matters enormously. Most flow applied systems must be installed with the substrate, material, and ambient air all between 10°C and 30°C, with the substrate at least 3°C above the dew point. Ignoring these conditions causes adhesion failure and surface defects.
Arturo’s PU vs Epoxy Flow Applied Flooring
Choosing between a polyurethane (PU) and an epoxy self-smoothing floor is one of the most important decisions in any flooring specification. Both are high-performance resin systems, but they have distinct mechanical and chemical properties that make each better suited to specific environments.
| Polyurethane (PU) - Flexible | Epoxy Resin |
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Arturo offers dedicated ranges in both chemistries. The Arturo Epoxy product range for chemical- resistant, ESD and heavy-traffic environments, such as EP2580, EP2500, EP2480, EP2490
The Arturo PU product range, including PU2030, PU2035 NEW, PU2050, and PU2060, for commercial, food production, and hygiene-critical applications. Both ranges share compatible primer systems, simplifying multi-zone specifications within the same facility.
When to choose PU flooring
Polyurethane flow applied flooring is the specification of choice in commercial environments and light industrial environments where functionality, sustainability and design aesthetics are required. They offer excellent resistance to wear and chemicals whilst providing flexible decorative options, available in various colours, with ‘concrete look’ effects or flake options, and can incorporate functional design elements such as slip resistance for safety. The flexibility of the PU accommodates small substrate expansion and contraction, dramatically reducing the risk of cracking. PU floors are also UV stable, making them suitable for any space with significant natural light where an epoxy floor might yellow over time.
When to choose epoxy flooring
Epoxy self-smoothing floors excel in environments demanding maximum chemical resistance, such as pharmaceutical manufacturing, chemical storage, laboratories, and automotive workshops. The highly cross-linked epoxy matrix provides exceptional resistance to acids, alkalis, fuels, and solvents that would degrade a standard PU system. For environments with constant heavy forklift traffic, epoxy's higher compressive strength and rigid bond to the substrate make it the more appropriate choice.
Flow Applied Epoxy Flooring in Depth
Flow applied epoxy flooring represents the most widely installed category of self-smoothing floor globally. Its combination of mechanical strength, chemical resistance, seamless finish, and relative cost-effectiveness makes it the default specification for a broad range of commercial and industrial settings.
How epoxy self-smoothing floors work
Epoxy resin systems consist of two components: an epoxy base (Part A) and a polyamine or polyamide hardener (Part B). When combined in the correct ratio, an exothermic chemical reaction (polymerisation) occurs, cross-linking the molecules into a rigid, thermoset polymer matrix. This matrix bonds chemically and mechanically to the prepared substrate, creating a monolithic surface.
The Arturo Epoxy Self-smoothing product range is engineered with precisely balanced rheology, offering approximately 25 - 35 minutes of workable pot life at 20°C, giving installation crews adequate time to pour and spread.
Different Types of Flow Used in Epoxy Flooring
Standard self-smoothing epoxy (1–3 mm): The most common system, offering an excellent balance of durability and cost. Suitable for warehouses, retail back-of-house, production areas with light forklift use, and healthcare corridors.
Anti-static / ESD epoxy floors: Formulations incorporating conductive carbon or metallic particles that dissipate static electricity, essential in electronics manufacturing, data centres, and explosive atmospheres.
Maintenance advantage: Because flow applied epoxy creates a non-porous, seamless surface, cleaning is dramatically simplified. There are no grout lines to harbour pathogens or accumulate dirt. A single daily sweep and mop is often sufficient in standard environments
Flow Applied PU flooring in depth
Polyurethane (PU) flow applied flooring has emerged as the system of choice for environments demanding performance and outstanding athletics. Where epoxy meets its limits, Arturo PU Smoothing floor range step in, offering a flexible, design and hygiene-focused alternative that does not compromise on surface quality or durability.
The science behind PU self-smoothing floors
Polyurethane is formed by the reaction between a polyol (Part A) and an isocyanate (Part B). Unlike the rigid thermoset network of epoxy, the resulting PU polymer retains some elasticity within its molecular chains, a property known as elongation at break. This elasticity is the key differentiating factor: when the concrete substrate expands and contracts due to temperature changes, the PU layer flexes with it rather than cracking.
Flow Applied Flooring Solutions & Use Cases
One of the most compelling reasons for the widespread adoption of self-smoothing resin floors is their versatility. The same fundamental technology, a liquid resin system that smooths under gravity, can be formulated and specified to meet radically different performance requirements across an enormous range of sectors.
Food and beverage production
This is arguably where flow applied flooring has made the greatest impact. Food production environments demand floors that are seamless (to prevent bacterial ingress), resistant to aggressive cleaning chemicals, including caustic soda and hypochlorite, thermally stable under steam cleaning, and safe underfoot even when wet.
Healthcare and pharmaceutical
Hospital corridors, operating theatres, clean rooms, and dispensary areas require floors that are impermeable, easy to decontaminate, and compatible with medical-grade cleaning protocols. Flow applied PU floors meet all these criteria. Colours can be specified to support zone demarcation and wayfinding. More details on hospital and healthcare resin flooring
Warehousing and logistics
High-bay warehouses with intensive forklift traffic need resin floors that resist point loading, abrasion from hard-wheeled vehicles, and chemical spills from battery charging. Heavy-duty flow applied epoxy systems at 1-3 mm are the standard solution, often with quartz aggregate addition for cost-effective installation. Line markings for traffic management, pedestrian zones, and racking positions can be incorporated into the system during application.
Commercial and decorative applications
Beyond industrial use, flow applied flooring has gained significant traction in commercial interiors. Architects and interior designers increasingly specify PU systems, sometimes with different pigments or coloured flakes, as a design-forward alternative to polished concrete or large-format porcelain tile. The seamless nature of the floor creates a visually expansive, contemporary aesthetic that is also highly practical.
Key Benefits & Considerations
Why specify a flow applied floor / self-smoothing floors?
Seamless and hygienic: No grout lines, joints, or porous surfaces for bacteria, mould, or debris to accumulate. This is non-negotiable in food, healthcare, and pharmaceutical environments.
Exceptional durability: A correctly specified and installed flow applied floor will outlast most alternative flooring options. Epoxy systems routinely achieve over 10 years of service life in industrial environments when properly maintained and can easily be resealed to prolong the service life.
Rapid return to service: Resin floors are typically trafficable within 24 hours and fully operational within 7 days. They are also durable and long-lasting, but when the floor eventually does become tired, they can be repaired or renewed quickly and easily. The floor can be recoated with a new colour or design without the need for removal and wastage associated with other types of floor coverings. This minimises operational downtime during refurbishment.
Design flexibility: Available in virtually any RAL colour, with a range of finish options from matt to high-gloss and flakes to slip-resistant options. Custom logos, zone marking, and decorative insets can be incorporated.
Chemical and stain resistance: Properly formulated epoxy and PU systems resist a wide range of chemicals, including fuels, oils, acids, alkalis, and cleaning agents. Specific systems can be selected for extreme chemical environments.
Important considerations before specifying
Substrate condition is critical: Flow applied flooring is only as good as the substrate beneath it. Weak, contaminated, or damp substrates will cause premature failure regardless of the quality of the resin system applied. Budget adequately for substrate preparation, it is not an area to cut costs.
Temperature sensitivity during installation: Cold or very hot conditions significantly affect cure times and flow behaviour. Work should be planned seasonally or, where necessary, with temporary environmental controls.
Slip resistance specification: Smooth self-smoothing floors can be slippery when wet. Always specify appropriate slip-resistant topcoats for wet areas, ramps, or any surface where there is a slip risk.
Ongoing maintenance: While low-maintenance compared to many alternatives, resin floors benefit from a documented cleaning and inspection regime. Abrasive cleaning agents and rotating brushes should be avoided. Localised damage should be addressed promptly to prevent water ingress and delamination.
If you need help writing a resin flooring specification for your project or have any questions, please call us at 01788 530 080 or email arturo.uk@uzin-utz.com.
