What types of Resins are available?

Several different resin chemistries are used to make flooring in the UK. The most common are epoxy, cementitious polyurethane, flexible polyurethane and MMA. Specialist floors may also use vinyl ester or phenolic epoxy.

They all create seamless resin floors, but they do not behave in exactly the same way. Each chemistry provides a different balance of strength, flexibility, chemical resistance, UV stability, working time, curing speed and cost.

Why are different resins used?

A warehouse, commercial kitchen, hospital corridor and chemical processing area place very different demands on a floor.

A warehouse might need resistance to forklift traffic and abrasion. A food factory may also expose the floor to hot water, cleaning chemicals, oils and rapid temperature changes. A car park needs flexibility and weather resistance, while a chemical bund may need protection against a specific concentrated acid or solvent.

Different resin chemistries allow the flooring system to be matched to these conditions.

The resin is not the only factor that affects performance. The thickness of the floor, type of aggregate, surface texture, topcoat and quality of the substrate preparation are also important. However, the resin chemistry establishes many of the floor’s fundamental characteristics.

What is mechanical resistance?

Mechanical resistance describes how the floor copes with physical use.

This can include:

• Abrasion from foot and wheeled traffic

• Impacts from dropped tools or equipment

• Heavy point loads from machinery or racking

• Forklift and pallet-truck movement

• Scratching and surface wear

• Movement or cracking in the underlying concrete

A hard resin may resist abrasion and indentation particularly well. A more flexible resin may be better at absorbing movement or bridging small cracks. Mechanical resistance therefore does not mean just one type of strength.

What is chemical resistance?

Chemical resistance describes the floor’s ability to withstand substances without softening, staining, swelling, cracking or losing adhesion.

The result depends on the exact chemical, its concentration and temperature, how long it remains on the floor and whether the exposure is an occasional spill or continuous immersion.

Oils, fuels, acids, alkalis, solvents, cleaning agents and food products can all affect resin systems differently. For severe exposure, the proposed floor should always be checked against a product-specific chemical-resistance chart.

Epoxy

Epoxy is the most commonly used general-purpose resin flooring chemistry.

It produces a hard, strong surface with good resistance to abrasion, traffic and a wide range of chemicals. It also bonds well to correctly prepared concrete and can be formulated as a thin coating, self-smoothing finish, textured broadcast system or heavy-duty screed.

Epoxy systems are widely available, familiar to flooring contractors and generally cost-effective. Their working time is usually more manageable than very fast-curing chemistries, making them suitable for projects of many different sizes.

The main limitation is UV resistance. Standard epoxy can yellow or change colour when exposed to sunlight, although this does not necessarily reduce its mechanical performance. Epoxy is also relatively rigid, so it may not be suitable where significant substrate movement or crack bridging is expected.

Cementitious polyurethane

Cementitious polyurethane is also called polyurethane concrete, polyurethane cement or PU cement. It combines polyurethane resin with cement and graded aggregates to create a thick, highly durable flooring system.

It is particularly effective where a floor must resist heavy traffic, aggressive chemicals, hot liquids, steam cleaning and thermal shock. This makes it a common choice for food production, breweries, dairies, commercial kitchens and other wet-processing environments.

Cementitious polyurethane normally costs more than a general-purpose epoxy system and requires experienced installation. Its working time can be relatively short, and some formulations may change colour under UV exposure without losing their physical or chemical performance.

It is selected because the operating conditions justify that additional performance.

Flexible polyurethane

Flexible polyurethane floors are designed to be more elastic than epoxy.

Their flexibility helps them accommodate limited substrate movement, absorb impact and bridge small static cracks. Depending on the system and topcoat, they can also provide good UV stability, improved comfort underfoot and some reduction in footfall noise.

These properties make flexible polyurethane suitable for commercial interiors, healthcare, education, leisure spaces, pedestrian areas and some car-park or deck applications.

The trade-off is that a flexible surface is generally softer than a hard epoxy or cementitious polyurethane screed. It may therefore be less suitable for severe point loading, aggressive mechanical wear or the most demanding chemical environments.

MMA

MMA stands for methyl methacrylate.

Its defining advantage is speed. Some MMA flooring systems can return to full service within approximately one hour of the final coat being applied. They can also cure at temperatures where many conventional resins would react very slowly.

MMA can provide good mechanical, chemical and UV resistance, making it useful for rapid refurbishments, cold stores, retail spaces, food production and projects where extended shutdowns are not possible.

Its fast reaction creates a very short working time, so installation requires an experienced team and careful planning. MMA also has a distinctive odour during application and normally costs more than a conventional epoxy system.

Vinyl ester

Vinyl ester is a specialist resin used where unusually aggressive chemicals, solvents or thermal conditions are expected.

It can provide extremely high chemical and mechanical resistance and is commonly considered for chemical-processing areas, bunds, containment zones and other severe industrial environments.

Vinyl ester systems generally have a shorter working time, higher cost and more demanding installation requirements than general-purpose epoxy floors. Their use is therefore normally limited to areas where the exposure cannot be handled reliably by a more conventional system.

Phenolic or novolac epoxy

Phenolic and novolac-modified epoxies are highly cross-linked specialist epoxy systems.

They are designed to resist particularly aggressive acids, solvents, caustic substances and, in some formulations, elevated temperatures. Typical applications include chemical containment, processing plants, tank farms, trenches and drainage areas.

These systems extend the chemical performance of standard epoxy, but they are more expensive and less versatile as general flooring finishes. Application conditions, working time and chemical compatibility must be considered carefully.

Which resin is best?

There is no universally best resin. There is only the resin system that best matches the conditions.

The correct choice should consider the expected traffic, impacts, chemicals, temperatures, sunlight, substrate movement, available installation time, required return-to-service time and project budget.

For many ordinary industrial and commercial environments, that assessment leads to epoxy. Where one of those demands becomes unusually severe, a more specialised resin may become the better choice.