Article No: 278

2010-09-24 11:09:12
Concrete Resurfacing: Not Just for Repair Anymore
By: Chris Sullivan


This kitchen floor by Becker Architectural Concrete of Minneapolis, Minn., is set apart from the great room with a beautiful micro topping overlay.

It is hard to pinpoint an exact date or even year when resurfacing concrete became a market of its own. Prior to the mid-1990s resurfacing concrete was only discussed when some sort of utilitarian repair was needed. Your color choice was gray, and maybe, if you were lucky, you could find a contractor who would add a little color or possibly stain the surface after application. Fast forward to 2010, and we find that the concrete resurfacing market has exploded. The resurfacing industry has come out from under the shadow of the catch all concrete industry, and become a legitimate market unto itself.

In the process, the concrete resurfacing market has found a new following and the products are now referred to as decorative overlays and architectural toppings. Within the new overlay market, trendy names such as Micro Topping, Chem-Rez, Skim Coat, and numerous others began popping up as the demand for trendy and colorful toppings grew.

In addition to color, the technology also kept pace. New polymers made the new generation of toppings stronger and more durable, able to withstand the harshest of both warm and cold climates. Of course, general resurfacing and repairing gray concrete will never go away, but the new trend offers contractors, homeowners and designers an endless choice of performance, durability, color, and texture.

Modern overlays or concrete resurfacing systems fall into four general categories. There is some overlap, but as a whole these product categories are determined by the function and design of the system. One thing to keep in mind is that most overlays are referred to as systems because they are typically comprised of multiple parts: primer, powder, liquid catalyst and a sealer to mention a few of the more common parts. Not all systems will have these parts, and some may have more. This is where your research and making sure the overlay you are looking to use is best suited for your particular application will pay off. The following overview discusses the major benefits and advantages of each of the five categories.

Concrete Repair Systems
These general purpose systems are all about strength and durability, and rank low on the color and design scale. They are primarily designed to repair concrete that has surface damage ranging from poor installation to freeze thaw induced spalling and scaling. These systems are usually cement based, and when mixed with a polymer provide excellent durability and strength in exterior environments.

Most concrete repair systems can be used for a wide range of applications; ranging from filling small patches to covering large concrete surfaces like a driveway or parking garage. They are applied with most any practical tool, including, but not limited to trowel, squeegee, broom and roller. They are applied thin, typically less than one-quarter-inch, and finished smooth or with a simple broom texture.

Micro Toppings
These are the new generation of thin concrete resurfacing systems. By combining the backbone and durability of concrete repair toppings with color and texture, these systems have become very popular with contractors and do-it-yourselfers as replacements for flooring such as wood, carpet, tile and sheet vinyl. Most micro toppings are cement based, utilize polymers (either dry or wet) and will contain varying sizes of sand that helps determine the performance characteristics of the product.

The most popular applications include residential flooring, residential patios, and commercial entryways and walkways. The two factors that set micro toppings apart from other concrete resurfacing systems is how thin they go down, with a typical multi-coat application going down at about the thickness of credit card, and the decorative flexibility.

Most micro toppings are available in a wide color pallet, and often take stains and dyes better than straight concrete. The way micro toppings finish is another distinguishing factor, allowing the applicator to achieve anything from ultra smooth to rough textured surfaces. One of the big reasons they have become so popular is their ease of application and the ability to create marbled and variegated tones within one or many colors. These tones allow the finished surface to look like stone or tile, or even unique artwork. If you are looking for a thin section decorative concrete alternative to common flooring products, micro toppings should be at the top of your list.

Stampable Overlay
Probably the least known of the concrete resurfacing systems, stampable overlays offer the end user a low-cost alternative to other natural materials such as rock, stone, tile and wood. Able to go down over any structurally sound concrete (or other) substrate, stampable overlays are designed to be imprinted so the finished product looks like some other natural material or surface. These systems go down in thicknesses ranging from one-quarter-inch to three-quarter-inch, and can go thicker in certain specialty applications.

The popularity behind stampable overlays comes from their ability to transform a plain gray concrete surface into one that resembles stone, tile, or even wood planks. Before these systems existed, the existing concrete would need to be removed, and a new concrete slab would have to be poured and stamped, costing the owner a lot of money. With a stampable overlay, the same textured look can be achieved, at a reduced cost and often without heavy machinery and damage to surrounding hardscapes.

Spray Texture While technically part of the micro topping family, spray texture systems do differ in how and where they are applied. These systems are most often found around swimming pools or on exterior patios in warm weather climates. They do not have the long term durability of micro toppings, but are typically not subject to very high traffic and wear. These spray systems are cement based, and some do contain polymers. They are available in a range of colors, and are applied with a low pressure sprayer / hopper gun that shoots the material down achieving the classic spray texture or orange peel look.

There are a few general rules of thumb that hold true of all resurfacing material or overlays. Surface prep is the most important. Any resurfacing system is only as good as the surface it is applied too. The surface needs to be prepared and roughed up to allow the system to properly bond. Delamination failures due to improper or poor surface preparation are the most common cause of overlay failure.

Proper application is another key factor universal to all overlays. Each system has suggested guidelines regarding how and when to apply the system. It is critical to follow the guidelines set forth by the manufacturer. Most resurfacing systems require some type of sealer to provide long term protection. These sealers can range from simple one part acrylics to two part high performance systems depending on the application. Lastly, it is very important to keep in mind that concrete resurfacing or overlay systems are subject to their surroundings. Selecting the proper system, along with proper application, is the key to long term success.

Chris Sullivan is the vice president of sales and marketing for Chemsystems Inc., a specialty manufacturer of Helix Color Systems, a premium line of decorative concrete admixtures and colorants. His responsibilities include managing all sales activities for the company in addition to new product development with an emphasis on troubleshooting application and technical issues. A speaker, author and blogger (Sullivans Corner on ConcreteNetwork.com), Sullivan is a certified technician with the American Concrete Institute (ACI) and lives in Denver, Colo., with his wife and three children.