Cement & Concrete: Types of Applications

by Darren
Cement intro Jnl 4 15

Take a deeper look at all the types of cement and concrete applications available to the industry and when to select which type of application.

When it comes to cement and concrete, there is such a wide variety of applications available to the flooring industry today that it can become a challenge to keep up with the latest developments and trends. As is well known and readily accepted, cement and concrete have travelled a path that has taken them beyond being considered just bland and boring.

The numerous applications will highlight all the possibilities when working with cement and concrete and, hopefully, offer further insight into the unique role these materials play in all types of settings.

Polished Concrete
A polished concrete floor has a glossy, mirror-like finish. The design options for polished concrete are vast, enabling one to choose the type of colour, create patterns with saw cuts, or even embed aggregates or interesting objects into the concrete prior to polishing.

Even the reflectivity of the floor can be controlled by using different levels of concrete polishing. These floors are popular in commercial buildings as they are easy to maintain, requiring just a mop and occasional use of a cleaning product.

Simply put, polishing concrete is similar to sanding wood. Heavy-duty machines equipped with diamond-impregnated segments or disks with progressively finer grit sizes similar to sand paper are used to gradually grind down surfaces to the desired degree of shine and smoothness.

During the polishing process an impregnating sealer is applied which sinks into the concrete and is invisible to the naked eye. It protects but also hardens and densifies the concrete. Some contractors spread a commercial polishing compound onto the surface during final polishing to give it a bit more sheen, which also helps to clean any residue remaining on the surface from the polishing process and leave a dirt-resistant finish.

Concrete can be polished using wet or dry methods, and although each has its advantages, dry polishing is the most commonly used method in the industry because it’s faster, more convenient and environmentally friendly.

Concrete Stencilling
The stencilling process can vary greatly, depending on the type of stencil used, whether the stencils are applied directly to existing concrete or an overlay, and the decorative effects one is trying to achieve.

The most popular techniques for stencilling concrete floors include:
•    Applying colour with chemical stains or water- or solvent-based dyes, either before or after the stencil is removed.
•    Creating an embossed pattern by trowelling or spraying a thin concrete overlay or skim coating over the stencil.
•    Etching designs into the concrete by lightly sandblasting or using a gelled acid that won’t seep beneath the stencil.
All these techniques will achieve better results with an adhesive backing that prevents movement of the stencil.

Using stencils with an overlay

Spray-down systems
Spray-down overlays work well with paper or plastic stencils, permitting the creation of intricate borders, custom designs and logos. Regardless of the stencil chosen, be sure that it is thick enough so that it won’t tear during removal.

Trowel-down microtopping systems
Because microtoppings are applied so thinly, they are ideal for use with adhesive-backed stencils to create decorative floor borders and other designs. After surface preparation has been completed, the base coat is trowelled down to the width of the stencil. The stencil is then adhered to the tacky base coat. Repeat this until the entire stencil is laid. A thin trowel topcoat can then be applied over the stencil.

Staining concrete floors
Staining is a very popular method for enhancing both commercial and residential floors. Concrete stains are highly versatile, allowing the creation of just about any look imaginable to suit specified design tastes and budgets.

Stains enable one to add subtle hints of colour, bolder design accents, and even custom graphics. In addition, stains can be applied to both new or existing concrete floors and work equally well with concrete overlays. Furthermore, concrete stains penetrate deeply into the concrete surface, and produce fade-resistant, permanent colour.

Depending on the desired look, there are two options: acid-based chemical stains or water-based stains. Acid stains penetrate and chemically react with the concrete, creating natural colour variations that add character and unique mottling effects, similar to the appearance of marble or granite. The acid in chemical stains opens the top surface of the concrete, allowing metallic salts to reach the free lime deposits. Water from the stain solution then fuels the reaction after the stain has been applied.

Other factors that affect the outcome include:
•    Cement properties and amount
•    Admixtures used
•    Type of aggregate used
•    Concrete finishing methods
•    Concrete age and moisture content when the stain is applied
•    Weather conditions when the stain is applied
•    Efflorescence

In turn, water-based stains come in a full spectrum of hues and in many cases the different colours can be mixed, like water-based paints, to broaden the range of options. Both options allow for an endless array of decorative effects. Although shades of brown and grey are the most popular stain colours for concrete floors, it can be beneficial to go for bolder shades to add more drama.

Painting concrete floors
One of the emerging trends in colouring interior concrete floors is by painting. Floors can be custom painted to create various looks and/or imitations such as marble, stone, slate or even a tiled appearance.

Companies are also using epoxy resins for base and colour coats, thereafter using a clear non-yellowing urethane for the durable topcoat finish. Epoxy floor coatings are hardwearing and durable solutions for both commercial and industrial flooring. As noted, they can be applied over concrete floors to provide a high-performance, attractive surface.

An epoxy floor coating over a concrete floor will create a high-gloss, hardwearing and durable surface. These floor coatings offer a number of benefits and advantages from the initial installation stages to long-term maintenance. For example, epoxy floor coatings are quick to install, durable and easy to clean.

When concrete is old and worn, it can be topped with a fresh, level layer that can be decoratively styled to match any décor. Overlays can be thick or paper-thin and used both indoors and outdoors. In fact, any design can be carried out on an overlay in the same manner that any design can be carried out on regular concrete, such as staining or polishing. The overlay simply offers a clean ‘canvas’ on which to start afresh.

These self-levelling overlays are flowable, polymer-modified, cementitious toppings that have the advantage of setting within a matter of hours. Through staining, saw-cutting, dyeing and grouting, overlays can accommodate an almost limitless range of designs. In addition, provided that they are properly and regularly maintained, self-levelling overlays will also last indefinitely while being less expensive than pricier alternatives.

Overlays fix and revitalise
Overlays can permanently cover up imperfections in existing concrete. The real challenge though is in choosing from the several resurfacing products available.  Polymer-modified overlays can be applied in layers without delamination or failure. They adhere well to existing concrete and resist damage from salts, chemicals, UV exposure, freeze-thaw conditions, and abrasion.

While most types of polymer-modified overlays offer similar performance benefits, each system has its own unique characteristics. With all these specialist products available, as identified above, the old belief that aged concrete with cracks, surface discolouration or surface imperfections must be removed and replaced, in order to improve the look of the concrete, no longer holds true.

If a concrete surface is in good condition it will require just a facelift, which means turning to stains, stencils or engraving to improve its appearance. Here overlays play a critical role; however, it is important to note that not all existing concrete can be resurfaced. The underlying base for any underlay needs to be sound. If the concrete is spalling due to damage from de-icing salts and freeze-thaw cycles or resting on unstable oil, resurfacing will not solve the problem. This is when total replacement becomes the only option.

With all the concrete applications explored above, it should excite the industry to know that there is so much to work with and choose from. This broadens the scope for specifers in terms of concrete flooring. However, it remains industry’s responsibility to teach clients about the options available to them and what would best suit their flooring needs.

Acknowledgement and thanks are given to the following for the information contained in this article: Cemcrete; Flowcrete SA; www.concretenetwork.com; www.concrete-floors.org; www.epoxyflooringandconcretestain.com

You may also like