Concrete Overlays Enhancing the Appearance of Concrete Floors

Concrete flooring has become very popular in the recent years and this is largely due to the decorative concrete overlays and other such finishes. Concrete is a very durable and resilient flooring material. It is low maintenance and can withstand a substantial amount of wear and tear. However, without proper finishing and coatings, it can look dull and drab.

An overlay can restore concrete to like-new condition or transform dull and drab, grey concrete with a brilliant pattern and/or colour to add value to the floors for a fraction of the cost of new concrete. An overlay can cover over imperfections and transform existing concrete into a unique custom floor. A well-designed and constructed concrete overlay floor provides excellent performance, in many cases extending the life of the floor surface for years.

Concrete overlay material is a blend of polymer resins. These are a mix of cement, sand, and other additives to create a more durable and attractive overlay. This blend also adheres well to the existing concrete without ruining its natural look. The concrete overlay can be stamped, dyed, and stained to achieve a beautiful final result. There are several concrete overlay options available to enhance the appearance of concrete floors. Each concrete floor overlay type offers different decorative options and performance attributes.

Factors to consider when choosing the concrete overlay

It is important to know that not all existing concrete floors can be resurfaced. The underlying base for an overlay must be sound. If the underlayment has severe cracks or other damage, resurfacing will not solve the problems and pouring new concrete will be the best option.

So selection of concrete overlay depends on the existing floor condition. If the existing floor has lot of cracks or pitting, or the surface is out of level then a higher-build material, such as an underlayment or self-leveling overlay, that can be applied at a thickness of 1/4 inch or greater, should be preferred.

Too much moisture in the concrete substrate can also be a problem for some overlay systems, especially products that restrict the ability of the concrete to breathe or release moisture vapor as needed.

While deciding on the concrete overlay, it is important to consider what type of conditions the overlay will be exposed to. Overlay system should be tough enough to withstand all the conditions it will confront. For example, if it is for floors that are exposed to heavy foot traffic and extreme conditions then durable overlays that are built to withstand wear and tear should be the choice. Some systems are better suited than others for harsher exposure conditions.

Another factor to be considered while deciding on the concrete overlay is the maintenance requirement. Most decorative overlays, when coated with a protective sealer, are very resistant to stains, dirt and grease. Still, they will need occasional cleaning to look their best. Floor overlays typically require routine sweeping to remove any abrasive particles and occasional wet mopping with a mild detergent, depending on how much traffic they receive.

Polymer-modified Overlays

Although cement overlays have been around for decades, many of today's systems blend polymer resins with cement, sand, and other additives to improve performance, wear resistance, and aesthetic qualities. Polymer-modified overlays are popular because they adhere well to existing concrete slabs and resist damage from UV exposure, extreme temperatures, abrasion, chemicals, and salt. Polymer overlays can be applied in very thin layers or up to several inches thick without delamination or failure, unlike standard concrete and cement mixes.

While most types of polymer-modified overlays offer similar performance benefits, each system has its own unique characteristics. Overlay manufacturers use different types of polymer resins, often blending them to produce proprietary products with distinct physical attributes. Many of today's decorative overlays use acrylics or acrylic blends because these resins provide excellent bond strength and UV resistance.

Stamped Concrete Overlay

Stamped concrete overlay is widely used for exterior surfaces but has recently become popular for interior floors as well. Stamped concrete provides a low-cost, durable solution, offering an ample range of colours and patterns from which to choose. Stamped overlay comes as a thin layer, typically 1/4 to 5/8 inch, of concrete that is applied to an existing floor slab and then is textured with a stamping tool to create the appearance of natural stone, marble, tile, or brick. The concrete can be tinted or dyed. For the final finish a coat of concrete sealer is applied after the pattern has been created.

Micro-Topping Concrete Overlay

A micro-topping is a cement-like product that is normally used as a solution to repair old cracked concrete. Applied to concrete surfaces, it strengthens and reinforces the concrete to render surfaces suitable for high-traffic areas. Applying micro-topping over concrete surfaces will generate a smooth surface and durable finish and improve the performance of the surface several times over so the floor won’t wear out and can withstand very high loads from equipment, foot traffic, and transport.

Micro-topping material yields an exceptionally smooth, tight-troweled finish that can provide a new “blank canvas” for decorative concrete floors. The result is a clean surface that can then be stamped, coloured or textured to look like nearly anything and fit with most design ideas.

Spray-down Concrete Overlay

Versatile and easy to apply, spray-down concrete systems offer a wide array of finish options. Usually, they are sprayed evenly onto concrete with an air-powered hopper gun, but they can also be applied as a splatter coat to create a textured, slip-resistant surface or "knocked down" with a trowel to create a smoother finish. A popular decorative technique is to use paper or adhesive stencils to produce designs such as borders and medallions, tile patterns, and embossed or inlaid motifs. They are very similar to micro toppings in that they are thin, but differ in that they usually contain more sand and provide a rougher, grittier finish.

Self-Leveling Concrete Overlay

A self-leveling overlay can be applied over most concrete floors and are thick enough to help correct uneven surfaces and relatively surface damage of old and worn out surfaces. It can be coloured with tints during the initial mixing, or coloured can be applied after it is applied and cured using dyes. One of the most important characteristics of self-leveling concrete is that it can provide a very dense and durable concrete floor. Most self-levelers can go down 1/4 inch to 1 inch, with the ability to be feathered into the existing floor to make a very gradual transition. Self-leveling overlays are especially useful when substrate conditions are old or worn concrete surfaces or unlevel floors, and concrete surfaces that are damaged by other floor treatments. Typical applications include commercial building lobbies and corridors, retail spaces, residential floors, restaurants, and warehouse floors.