Polyurethane Concrete: The Floor Solution for Food Plants

• Ahmet Toka
• 7 August 2026
• Floor Coating
• 4 min read

Almost every floor coating failure in food production plants comes out of the same scenario: the floor is washed with hot water or steam, the coating and the concrete expand at different rates, the stress between them overcomes the bond and the layer lifts. This is a problem of system selection, not of material quality.

Polyurethane concrete is a system developed to solve exactly this problem. In this article we explain how it works, why it differs from epoxy, what thickness it should be applied at and how the hygiene details should be built.

In a food plant the floor is chosen according to the cleaning regime. If hot water and steam are used, the discussion ends: the system has to withstand thermal shock.

Ahmet Toka, General Manager

What Is Thermal Shock, and Why Does It Lift a Coating?

Every material has a coefficient of thermal expansion, which determines how much it lengthens and shortens when the temperature changes. Concrete and resin coatings have different coefficients.

When water at 80 °C is poured onto the floor, the coating layer heats up and expands rapidly, while the thick mass of concrete beneath it reacts far more slowly. This differing movement between the two layers creates shear stress at the bond interface. Nothing happens the first time; but repeated several times a day, this cycle gradually fatigues the bond and the layer begins to lift at the edges or around the joints.

With standard epoxy systems this can be seen within the first year after the plant comes into service. The source of the problem is not the quality of the coating but the fact that it was not designed for that use.

How Does Polyurethane Concrete Work?

Polyurethane concrete (PU concrete, polyurethane cement) is a hybrid system in which polyurethane resin, cement and selected aggregates are used together. Thanks to its cement content, its thermal expansion behaviour is very close to that of concrete. In other words, the coating and the substrate move together and the stress created by thermal shock is largely eliminated.

The second important property of the system is its moisture tolerance. Because it contains cement it can be applied to fresh, damp concrete; this removes the concrete drying time that is a serious constraint in epoxy and polyurethane systems. In newly built facilities this saves weeks in the programme.

Its third property is chemical resistance: it resists lactic acid, fatty acids, sugar solutions and cleaning chemicals. The organic acids encountered in food production soften standard epoxy over time, whereas PU concrete withstands them. Details: polyurethane concrete coating.

Thickness and System Selection

Polyurethane concrete is a system that behaves differently according to thickness. The thickness decision is an engineering decision based on the conditions of use, not an aesthetic one.

• 4 mm and below: Light wet cleaning, medium load. Dry production areas and storage zones.
• Around 6 mm: Regular hot-water washing, medium to heavy traffic. The majority of food production areas fall in this range.
• 9 mm and above: Steam cleaning, heavy impact, hot liquid spills. Cooking, blanching and sterilisation areas.

The surface texture is chosen separately. In wet and greasy areas the aggregate density is increased for slip resistance; this requires striking a balance between cleanability and safety. An excessively rough surface increases slip safety but makes cleaning harder.

Hygiene Details: This Is Where the Real Difference Shows

In a food plant the success of a floor coating is measured not in the open areas but in the details. These are also the points that cause problems in inspections.

• Coved skirting: The floor-to-wall junction is not left as a sharp corner; the coating is carried up the wall as a cove. In this way no gap is left in the corner for dirt to collect and cleaning can be done in a single movement.
• Channel and drain connections: The coating is not brought only as far as the edge of the channel; it is turned into the channel and terminated there. This is the point where water most often leaks and deterioration most often begins.
• Falls: The floor must be laid to fall towards the drainage points. Hygiene cannot be achieved on a food plant floor where water ponds.
• Anchor cuts: The edges of the coating are terminated by being set into thin channels cut in the concrete; this removes the risk of lifting at the edge.
• Joints: Movement joints in the concrete are carried through the coating as well and sealed with a suitable elastic filler; for details see joint sealing applications.
• Machine feet and plinths: Equipment plinths must also be wrapped in the coating, leaving no gap between the floor and the plinth.

Application Process and Return to Service

1. Surface preparation. The surface is opened up by shot blasting or milling; the laitance layer is removed completely.
2. Anchor channels. Cuts are made at all edges where the coating will terminate and around channels.
3. Repair. Voids, breakouts and joint edges in the surface are repaired; if necessary concrete damage repair is carried out first.
4. Correction of falls. Areas where water ponds are graded towards the drainage.
5. Main layer. Polyurethane concrete is applied by trowelling out at the chosen thickness; the surface texture is formed at this stage.
6. Completion of details. The coved skirtings, channel returns and plinth wrappings are applied.
7. Curing and return to service. Pedestrian traffic is generally possible within a day and full chemical resistance within a few days. This is shorter than with epoxy systems and creates an advantage in facility planning.

For a comparison with other floor systems see floor coating applications page.