Furniture makers and designers have used concrete to make fittings and home accents for a lot longer than you’d expect! Despite its reputation as an industrial material used in roads, dams, and massive building projects, concrete is incredibly versatile. We use it to make our urban and residential outdoor furniture!
While you can use ordinary concrete for furniture projects, certain types are better to use. It all comes down to the “recipe” of the concrete because, at it’s most basic, it’s a simple material that uses only three ingredients!
What Is Concrete?
At its most basic, concrete is a mixture of three elements:
- Crushed stone, gravel, or sand (aggregate)
- Portland cement
When the cement in powder form is mixed with aggregate and water, it acts as a binding agent of the mixture. The concrete is then shaped or poured into moulds, where it hardens into the desired shape. However, the ratio of these materials can change their strength, stability, and usefulness.
In the early days of concrete furniture, the projects were made using thick, heavy concrete reinforced with a material like steel. As such, thinner and more delicate furniture was either impractical or impossible. But improved setting and moulding techniques have made it possible to create concrete pieces with more sophisticated shapes!
What Kind Of Concrete Mix Is Ideal For Furniture?
Now, to make a concrete furniture product, we have to use the right mix of cement and aggregate. For furniture construction, a standard concrete mix you’d find on a construction site can be useable, especially if the furniture is to be cast in place. However, controlling water content to increase strength and durability and minimize shrinkage is very important.
Most workable concrete mixes have water-to-cement ratios of 0.40 to 0.60. A higher ratio of water to cement than this will reduce strength, durability and abrasion resistance while increasing the potential for shrinkage and cracking. It’s necessary to use a type of concrete called “water-reducing admixtures”; these keep the water content on the low end of the scale, between 0.40 and 0.45. Water-reducing admixtures have been shown to increase the compressive and flexural strengths of concrete, making them ideal for furniture projects like outdoor benches!
How We Use Concrete For Our Furniture
Even properly-mixed concrete for furniture isn’t always ideal for sitting on – after all, it is a hardened combination of various types of rock. But only poorly-planned concrete elements are truly uncomfortable because it’s easy to use concrete with other materials. Properly-treated wood adds comfort, function, and style, and we use it in our line of X CRAFT benches.
Water-reducing concrete has the advantage of being a unique material. We can make furniture in shapes, textures, and durability that aren’t possible with any other material! It also has unrivalled durability, making it a popular material for public spaces.