Concrete countertops are gaining in popularity due to their durability, attractiveness, and design flexibility. A decorative concrete counter will provide a smooth and durable work surface that will be the centerpiece of any kitchen, bathroom, showroom, office, or workstation.
There are two primary methods for: cast-in-place or precast. As the name would suggest, precast concrete countertops are created offsite. The contractor will build a form based on the design, pour, and finish the countertop in the workshop. This allows the contractor to control variables such as temperature and humidity. It also significantly reduces the mess created at the customer’s home or business. Precast countertops do have some drawbacks, namely transporting the counter to the installation site and accommodating intricate designs. When transportation and placement are expected to be problematic, or an intricate design is called for, it may be desirable to cast the countertop in place. With this method concrete is poured on site. By placing the concrete in its final location, concerns about transportation and conforming to complicated designs can be mitigated. This method, however, does come with additional mess concerns and a loss of control over the conditions.
Certain factors need to be considered to ensure the performance, durability, and feasibility of the design:
Thickness: Standard thickness for concrete countertops is between 1.5 and 2 inches. Anything thinner would lack the rigidity and strength necessary to support itself, while anything thicker would be prohibitively heavy. Often, drop edges are incorporated to give the appearance of greater thickness.
Weight: Material weight varies based on mix design. Generally speaking, however, a 1.5 inch thick concrete counter will be similar in weight to a comparable granite counter top. Other materials, such as marble, laminate, and tile will be significantly lighter but less durable. Contractors will generally use lightweight concrete mixes. Some of these mixes utilize lightweight aggregates such as expanded clay or shale. Other designs, like Glass Fiber Reinforced Concrete (GFRC), rely on high strength to reduce required thickness and cement content. A finishing aid such as Day1 can offset the stickiness often found in lightweight blends such as GFRC.
Strength and Durability: This unique application of concrete requires some degree of reinforcement, otherwise the concrete countertop may become subject to excessive cracking and flexing. For this reason, welded wire fabric and/or fiber reinforcement are very important. UltraFiber 500 (a natural cellulose reinforcing fiber offered by Solomon Colors) is an excellent option when compared to wire and synthetic fibers because UF500 is better at reducing shrinkage cracking, improves flexural strength, is invisible in concrete, and accepts color from pigment and stains. Ensuring the countertop is properly supported, placed on even and level surfaces is also vital to preventing cracking.
Design flexibility is where concrete countertops shine over other materials. They can be cast in nearly any shape. There are a multitude of color, finish, and embellishment options, as well. Here are a few options.
Color: Materials such as granite and marble are limited by nature. Concrete, on the other hand, can be pigmented and stained with a variety of subtle and classic or wild and bombastic colors. Integral pigments are often used to give the countertop a single, consistent color. This color can later be accents or modified with a stain or dye. Stains or dyes can create more unique color patterns, designs, and even logos. Often times, two or three colors of acid stain will be used to create rich, deeply colored, marbled designs. A penetrating dye may then be used to more precise designs such as stencils, borders, and logos over the stain.
Texture: Generally, it is not desirable to have texture on the surface of a countertop. This makes the surface less usable. However, texture can be applied to the edges with specially designed form liners or with repurposed texture skins (results may vary with that method). Form liners attach to the form when the countertop is cast, molding the edge in any one of a variety of classic shapes. If the design does call for surface texture, a light imprint of a textured skin may be used to give some dimension without interfering too much with functionality.
Finish: A polished countertop, if done correctly, provides a glass-smooth surface that is durable and low maintenance. To achieve this, the contractor will grind smooth the surface of the counter, then apply a densifier to close pores and harden the surface. Periodic resealing or retreating may be necessary. Polishing may not be compatible with certain aggregates, designs, and lightweight mixes, however. In those cases, it is best to use a traditional sealer to protect against wear and tear, stains, and provide a smooth, attractive surface. Traditional coatings and sealers, however, may require more frequent retreatment and maintenance. Polished and unpolished surfaces are both compatible with integral color, stains, and penetrating dyes.
Solomon Colors offers materials for both finishes. Lythic Densifiers and Protectors provide an environmentally friendly option for polishing. Lythic products are free of harmful Sodium, Lithium, and Potassium that can leave cloudy residue. Brickform Decopoxy, Poly-Astic, and Uremax can be used to seal non-polished countertops and are FDA US Food Code 6-101.11 compliant.
Concrete countertops become truly exciting when all of the unique design options are considered. Concrete can be used, quite successfully, to mimic traditional natural and manmade materials. It can, however, also be used to do some unique and wild things. For example, imprints of shells, leaves, and hands can be made on the surface. Various minerals, recycled materials such as glass, and even LED lights can be embedded in the counter as well. The form of the counter itself can even be used as a design feature with integrated shelves and backsplashes or sinks that seamlessly are seamlessly incorporated. This aspect is truly limited only by one’s imagination.