Technical Articles

Coloured concrete floors are attractive and distinctive, and can greatly improve the appearance of a building, and reinforce the company’s branding.  Ibrahim Fleyfel of RCR Flooring Products explores the options for colouring an internal concrete floor.

Coloured concrete floors are attractive and distinctive; they can greatly improve the appearance of a building and reinforce the branding of an organisation. Ibrahim Fleyfel of RCR Flooring Products explores the options available.

 

Paint

Concrete floor paints are available on the market, some of which are marked for industrial use. However, preparation is vital – if the concrete slab is not porous enough, the paint may flake off once the floor is brought into use. Also, if you want to colour a larger area such as an industrial floor or warehouse, painting may be very time-consuming, costly and labour-intensive. Painting is probably best suited to a small area with light traffic.

 

Stain and dye

Acid and water-based stains form a chemical reaction within the concrete to create permanent colour effects on the surface. The concrete can be stained even if it’s been in-situ for a while.  Patterns and variety can be created by staining different areas of the floor in different colours.

Acid-based stains offer fewer colour choices than water-based; and the nature of the process means that the results may vary from one floor to another. Acid-based stains also tend to produce translucent results, which may mean that stains on the floor will still show through.  Water-based colours can be more solid.

Dyes also provide permanent colour and are usually water-based or solvent-based. They colour the concrete by permeating the surface, not through a chemical reaction; and the results may be translucent with water-based dyes.

 

Tinted sealer

A tinted sealer adds a wash of colour over the concrete, while sealing the surface. Solvent-based sealers give a more solid finish than water-based ones. A tinted sealer may be appealing if a large area needs to be treated with one colour or if an existing colour needs to be enhanced. Water-based sealants may not work well when applied with a sprayer, as the paint and water can separate. Tinted sealers are not a permanent solution – the floor will may need resealing after some time, due to normal wear and tear.

 

Colouring the concrete mix

This method applies to new concrete floors, or the major surfacing of existing slabs. Adding a pigment to the concrete mix will colour the entire batch; the concrete will be coloured throughout, not only near the top surface level. This process, although good for creating large blocks of solid colour, is an expensive way to achieve a coloured concrete floor, as switching to use different colours in different areas of the floor would require different coloured concrete mixes. Using this method, concrete that is several centimetres below the surface of the floor will be coloured – adding an unnecessary cost to the project.

It should be noted that none of these four colouring methods improves the durability or lifespan of the floor or protects the concrete from impact or abrasion damage: they simply add colour.

 

Resin coating system

This is an option for both new and existing floors. Resin coating systems – such as Rinol systems from RCR Flooring Products – add colour and shine to industrial, commercial and residential floors, and can also be used to create decorative patterns. Resin coasting systems are used when the surface needs to be highly durable, chemical, temperature or slip resistant and easy to clean.

The liquid components of the system are mixed and applied to the slab, where they set to form a hard polymer surface; the surface may be built-up in two or three different structural layers on top of the concrete base.

For existing floors, preparation is key to ensuring a good result – the surface needs to be clean, and permeable enough to accept the resin coating. In any scenario, it may take several days to create the resin floor, as the layers require curing. Time and cost should therefore be taken into account. For more information on resin flooring systems, visit: www.ferfa.org.uk

 

Colour hardener

A concrete colour hardener – also called a coloured surface hardener – can be applied to both new and existing floors. A common application method is as a dry-shake powder on top of freshly poured concrete. The powder is applied as soon as the concrete has been screeded, thus not adding an extra stage to the construction process. This helps to make surface hardeners a cost-effective way to colour a large industrial or commercial floor, or even sections of the floor in different colours. For smaller areas, a surface hardener can be mechanically or manually applied.

Unlike the first four methods discussed, surface hardeners also extend the life of the floor, by improving its resistance to damage caused by dropping, scraping or spillages. Colour hardeners can also be applied to new or existing concrete floors as a pre-mixed wet slurry topping, a ‘wet-on-wet’ application. Although this is more expensive and requires more manual work than the dry-shake process, it produces a better colour and a more durable floor. Both large and small floor areas can be treated with equal success. For existing substrates, it is important to ensure an appropriate bonding agent is used first.

This article was published in Concrete magazine, March 2018.