STAMPED CONCRETE FINISH
- An Introduction
05 April 2020
Eric L.S, Soong
Simon K.K, Soong
Stamped concrete popularized in the United States in the 1970s was beginning to make its way to Malaysia in the late 1980s. The systematic method of concrete stamping was introduced by a gentleman named Brad Bowman in the 1950s. After making its foray into Malaysia, this new trend of decorating concrete began slowly to gain momentum in the county. Once dominated by plain concrete finishes, interlocking pavers and floor tiles, today stamped concrete has been trending throughout the county and found favour among the local architects and designers.
Stamped concrete exhibits a unique trait in being able to blend a variety of colors and patterns together. This special property is what makes it a popular feature for decorating roads, driveways, walkways, patios and many more places. It also offers a variety of pattern options ranging from wood textures to slate textures. Other benefits of using stamped concrete include among others its affordability, the durability of the product and its requirement of not needing much maintenance.
The Early Years
In the early years of stamped concrete, the works were largely concentrated in individual luxury houses. In the late 1980s and early 1990s as the trend began to pick up, stamped concrete was being installed in larger volume and scale.
Stamped concrete began to feature prominently in many housing developments as it accords a uniqueness to the development. Specifically the stamped concrete works in these developments would generally adopt a single pattern with a two- tone color system to attain a more realistic feel to the design. The blending of colors were typically achieved by combining different products such as colored release powders.
The Later Years
Forty years since stamped concrete was first introduced in Malaysia, it continues to be one of the pillars in both the residential and commercial building sector and is a common product offered among decorative concrete contractors. However, customization and differentiating designs are the new normal in this day and age.
Designers and architects are now adding their creative touches to the finishing design by using existing moulds and other decorative products to give it a unique outlook. In order to realize this new feat, contractors are turning to hand tools to create the finer designs such as customized groove and post coloring techniques, for example stains, to blend multiple colors.
The stamped concrete industry do have its challenges. Some of the challenges encountered by decorative concrete contractors often include, among others, issues such as surface delamination, crusting cracks and lack of pristine textures on the final product.
Many contractors shared the common problem on surface delamination, though in many ways it is not a reflection of the stamped concrete product itself. The main culprit more often than not is that insufficient time to allow the excessive bleed water to escape before broadcasting the color hardener onto the concrete surface. A little concrete bleeding will be beneficial to facilitate working with the dry shake color hardener but excessive concrete bleeding is one of the causes for delamination when the bleed water and air accumulated under the dense hardened color hardener, unable to escape. Another major cause of delamination is over-layering resulted from broadcasting the color hardener onto hardened concrete, followed by wetting and floating the surface. This issue can be mitigated by adjusting the concrete mix design to reduce concrete bleed water and to improve the workability with sufficient time for finishing.
Crusting cracks is another issue seen on some finished works. Whilst the cracks themselves do not generally affect the durability of the concrete slab; their appearance is unsightly on the finished product. These cracks are mainly found near the stamped joints near the edges of the imprinted texture. This occurs as the surface loses water rapidly and has hardened before the rest of the concrete is allowed to set and tends to amplify during hot and windy days. Small cracks are formed around the stamped joints as the stamp mats are pushed into the crusted surface, and the surface tears apart due to stresses. This issue, however could minimized by erecting a shade when casting during a hot day and by putting up temporary wind barriers to reduce the wind velocity on the surfaces.
Lack of texture on the finished products is a common issue faced in the industry. A major factor that causes this issue is the type of concrete mix used during the stamping process. Concrete mix with large amount of coarse aggregates could interfere with the impression of the stamping process. One way that this could be minimised is to thus ensure the appropriate size and type of aggregates contained in the concrete mix, and in this regard, the experience of the decorative concrete contractor matters.
Building a unique concept with stamped concrete
A better understanding of concrete behavior and how the work surroundings could impact upon the final product are essential in bringing up, and capitalizing on, the many great features accorded by decorative stamped concrete products. These factors together with the growing diversity in stamped concrete designs as well as the continuing advancement in concrete technology in Malaysia will be strong sustaining driving forces to propel the decorative stamped concrete industry forward.