Concrete is one of the most versatile materials available. If you can dream it up, it’s pretty likely it can be created with concrete. From bar tops and kitchen islands to fireplace surrounds and desks, concrete is the ideal material.
At Trueform, we are masters of bringing ideas to life through the medium of concrete. Take a little tour behind the scenes with us to learn more about the process we go through to make stunning concrete furniture and more.
Plans & Drawings
Concrete manufacturing facilities can function differently from each other. Some produce standard products, day in and day out. Others are “job-shops” that create one-off, custom pieces.
Regardless of what a manufacturer produces, they need specifications in order to begin the project - typically in the form of a technical drawing or a standard purchase order.
Because some type of mold/form will need to be either identified or assembled, specifications act as the “plans” capturing information essential to the fabricator during each phase of production. These specs are then taken to the manufacturing floor and referenced while building or retrieving the mold.
Mold Making & Assembly
Concrete will take on the shape and texture of whatever it is poured into or onto. So, before any pouring or spraying can begin, molds (or forms) must be produced. A mold can be regarded as the “negative” of the finished piece because its goal is to yield a “positive”—the finished concrete piece.
Manufacturers utilize a variety of non-porous materials to create molds/forms to exact specifications. For standard production, fabricators employ reusable molds as often as possible to reduce waste and increase efficiency. These molds are typically made from steel, silicone/rubber, PVC, or fiberglass. Molds for custom pieces may employ other materials as they are often designed for single use.
Batching & Mixing
Once the molds/forms are created, the exact amount of concrete mix is then calculated and weighed out in order to minimize waste. These ingredients include: portland cement, sand, glass-fiber, water, color pigments and other additives that make our blends the best in the market.
The ingredients are methodically loaded into different types of concrete mixers, depending on the type of project that is being cast. The loading order, timing, temperature, and ingredients themselves all create variables and challenges to getting the concrete to behave properly.
For example, plasticizers can be used to reduce the viscosity of the concrete mix to a near-water consistency without having to actually add water. Once the perfect consistency is reached, it must be cast as soon as possible.
GFRC, the concrete type we use, is a composite material that can be cast using a few different methods. The method employed depends on the shape and complexity of the piece being fabricated, the desired thickness, the skill level of the fabricator, and the tools at their disposal.
Spray Up Casing
One casting method is known as the spray-up process. This is where the fabricator uses a “chopper gun” that mixes glass fiber from a spool with concrete while it is being sprayed into forms and molds. The fabricator will make several passes, building up layers to the desired thickness. This method produces our strongest products.
A second method is a hybrid or spray and pour process. It’s a two-layer method with the first layer (facecoat) being a thin surface layer sprayed with a gun directly to the mold. A thicker GFRC mix that contains glass fibers (backer) is then added underneath the face coat in order to provide strength and help achieve the overall desired thickness. This backer coat is either poured in or “hand-packed. Hand-packed GFRC is “thick” enough to be sculpted and is often used on pieces with vertical surfaces since it can retain its shape.
Wet Cast Pour or Self-Consolidating Concrete
A final method is a wet cast pour or SCC Pour (self-consolidating concrete). Here, a low-viscosity mix is poured directly into a form or mold. This process typically requires some level of agitation to accelerate consolidation and remove air bubbles as they will result in small holes in the surface of the concrete.
Curing & Demolding
After the concrete is cast, it must cure from three hours to three days depending on the mix design, the application, and the minimum strength the concrete needs in order to be safely removed from the forms. Once the concrete has cured to the manufacturer’s protocols, it is removed from the forms.
The final step in the GFRC fabrication process, and one of the most important, is finishing or processing. This is where the cured piece is refined—elevated from a rough and raw concrete object to a functional piece of art. Because the visible surfaces need to be both durable and aesthetically pleasing, great care must be taken by the fabricator in order to yield a beautiful, high-end product.
The finishing process will vary and depends on the desired application. Some pieces are designed to retain as much of the concrete’s authenticity as possible with just some light sanding and that’s it. Others require a far more labor-intensive process.
A thorough finishing process may include wet polishing, filling, sanding, and sealing. Because it is inherently porous, decorative concrete should always be sealed. And the material and method used to seal concrete is key in determining how resistant the surface will be to staining and damage by UV rays.
Whether you order a countertop in a custom color or choose one of our elegant concrete dining tables, our dedication to the finest bespoke craftsmanship remains the same. From building molds to finishing, our processes create products that are as functional as they are works of art.
Take a closer look at how decorative concrete can enhance your spaces.