“…the floor is the most important part of the building. All activities occur on or near the floor and the remainder of the structure is simply a means of protecting the floor and workforce from the environment.” Peter Norton
This is an oversimplified definition of an industrial floor perhaps, but it adequately describes the importance that flooring has for any application, and subtly emphasises the fact that architects, engineers and end users should pay strict attention to the correct floor specifications if they are to meet the demands that it will encounter.
The desirable properties required of industrial floors include high wear resistance; good compressive and flexural strength; overall dimensional stability; zero cracking; and zero curling or warping.
These requirements are essential in many applications including factory floors of all descriptions; cold room floors; hardstand areas; and industrial parking garages and driveways.
Concrete industrial floors
The most common flooring for industrial applications is concrete, and over the past decade or so there have been many changes taking place in industrial flooring, particularly in warehouses due to the increase in fast-moving consumer goods; the requirement for larger warehouses and higher racking; more efficient distribution methods; faster forklifts; and round-the-clock operation.
Most experts agree that, to obtain the best performance and service from these floors, meetings should be held between the end user, the engineer and a specialist flooring contractor at the design stage or, at the latest, before construction commences.
This should obviate problems such as poor specification and the quality of sub-base material, as well as insufficient attention being paid to concrete mix design and inappropriate level and flatness specifications. Timing of the installation and adherence to curing times can also be established.
As these floors are often subjected to the most stringent working conditions, it is preferable to have seamless floors, which thereby provides the elimination of joints (or at least the minimum number of joints) in the floor surface, because jointed floors often present a large number of problems and failures.
These include damage to the joints caused by heavy traffic or regular forklift traffic in the same areas which in turn requires specialist repairs; the safety of personnel working or walking in these areas; the ‘bouncing’ of laden forklifts as they go over the affected areas; the damage to and replacement of forklift tyres and other parts.
Self-healing and self-compacting concrete floors, developments in floor screeds and toppings, ultra-thin reinforced concrete, and an increasing usage of post-tensioned floors – all reported on in the Cement & Concrete feature in our previous issue – are indicative of the considerable developments currently taking place in concrete industrial flooring.
Epoxy and resin industrial flooring
Epoxy and resin floors are now tried and tested answers for the provision of durable and lowmaintenance industrial floors. Offering high chemical, slip and thermal resistance as well as hygienic properties and an excellent service life, these epoxy and polyurethane coatings are nonporous, react favourably to hot or cold conditions, and have been designed to perform in the most demanding applications.
The durability of these coatings is exceptional and they lend themselves to heavy-duty applications because they are resilient, easy to clean and maintain, thus making them ideal for any area that requires tough stain-, chemical-, dustand water-resistant flooring.
Application is often in a liquid form and usually consists of a primer base and a “decorative” option and can be trowelled or rolled on and applied in extremely thin applications or several centimetres thick as in mortars.
Also known as polymer flooring, they typically come in a clear application or in a wide variety of colours from the standard black and white, through the neutrals, moving on to bright and modern designs. Corporate colours and logos in the floor can also be provided.
Synthetic resin types
Various types of synthetic resin systems are available which can form the binder of a flooring system. These include typically epoxy, polyurethane and methacrylate resins. Different resin types give different combinations of application characteristics and in-service performance, and the classification of these flooring types is shown below:
Synthetic resin floorings can be divided into different types varying in thickness and surface finish:
Floor seal: Applied in two coats to give a dry film thickness up to 150 μm: generally solventor water-borne.
Floor coating: Applied in two or more coats at a dry film thickness up to 100 μm per coat; generally solvent-free and water-borne.
High-build floor coating: Applied in two or more coats to give a final thickness of 300-1000 μm; generally solvent-free.
Multi-layer flooring: Multiple layers of floor coatings or flow-applied flooring with aggregate dressing, having a thickness greater than 2mm; often described as ‘sandwich’ systems.
Flow-applied systems: Applied between 2-3 mm in thickness. Often referred to as ‘self-smoothing’ or ‘self-levelling’ flooring and having a smooth surface; or may be given a surface dressing.
Screed flooring: Heavily filled, trowel-finished systems applied at a thickness greater than 4mm, generally incorporating a surface seal coat to minimise porosity.
Heavy-duty flooring: Aggregate filled and applied between 4-6 mm in thickness and having a smooth surface; or may be given a surface dressing.
Heavy-duty screed flooring: Trowel-finished, aggregate-filled system applied at a thickness of 6mm or more and effectively impervious throughout its thickness.
In general terms the above categories of flooring are listed in ascending order of durability. However, the actual life in a particular installation will depend on the product formulation used, the quality of the substrate and the degree of severity of the service conditions.
The main advantages of synthetic resin floorings can be summarised as follows:
- strong permanent bond to the concrete base
- excellent resistance to a wide spectrum of aggressive chemicals
- impermeable to liquids
- increased toughness, durability, resilience, and resistance to impact or abrasion
- hygienic and easily cleaned surfaces
- greater resistance to cracking
- low applied thickness
- rapid installation and curing with minimum disruption to normal operations
Acknowledgement and thanks are given to the following for information contained in the compilation of this article: TotallyConcrete Expo; Lafarge South Africa; The Concrete Institute; Flowcrete South Africa; and FeRFA (the Resin Flooring Association).