Wire-cut bricks are cured or fired pieces of clay that have been formed into brick shapes with the aid of a wire cutter of some sort. The simplest cutters are little more than wire cording that people press into large mounds of clay to divide it into smaller portions. There are usually a number of options, though, including wire “cages” and cheese-cutter type grates that can be pressed over wet clay in order to form it before it has a chance to harden. Discounting bricks made and formed entirely by hand, wire cutting is one of two primary means of brick making. It is very efficient and, when done properly, will yield bricks of uniform size; depending on the clay being used, though, bricks made this way do tend to be more porous and weaker than those made by pressing clay into molds or forms. They also typically have a very noticeable rough edge or finish to them, owing to the friction and tension as the wire was pulled across the surface. Sometimes this texture is desirable, but not always.
There are two primary methods most manufacturers use to shape bricks in bulk, namely pressing and wire-cutting. The pressing method creates a brick by pressing clay material into a brick mold or form and applying pressure. This method tends to be somewhat time-intensive and expensive, though it does typically produce very strong bricks of a uniform size and shape.
Wire-cut bricks, by contrast, are bricks formed by slicing a brick-sized piece from a bulk-length of clay with a wire tool. After the clay is formed into a large, rectangular piece of material, it is sliced into several brick-sized pieces by pushing wires through the clay. The slicing of the clay in wire-cut bricks leaves a noticeable whiskered-type appearance in the cured surface of the brick. The slicing procedure creates something of a rough texture as the as the wire is pushed and forced through the material.
Types of Wire Tools
Manufacturers using the wire-cutting method usually have a couple of options when it comes to tools. Bricks are often formed as a large block of brick material and pushed through a die onto a cutting pan. Once pushed through the sizing die, the block is sliced into several brick-sized pieces by forcing a large, cheese cutter-like tool through the block of material. It’s also possible to use a tool that looks more live a woven grate or large screen that’s pressed over a wet mound of clay, and even simple strands of measured wire can be used to cut individual pieces.
The Process as a Whole
When the bricks are sliced by the wire, it pulls the edge of the brick, stressing the clay and creating small cracks in the surface of the stretched material. As the wire-cut bricks are fired, a process that heats the bricks and sets them into a permanent shape, the moisture in the clay is baked out and the molecules of clay heat together and strengthen into a long-lasting building product. The stretch marks on the surface of the baked brick separate into rough cracks and crevasses. This feature is what gives the bricks the visual appeal that many builders and homeowners seek in a finished appearance.
Advantages and Drawbacks
One of the biggest advantage to the wire-cutting process is that it produces a much more affordable product; bricks made this way are easier to produce, require less material, and also take much less time to create than a pressed version of brick. A typical block of clay will produce six to nine bricks once cut and cured. Four- or five-person teams typically manufacture bricks with a single brick-making machine. Two people commonly shovel the clay brick material into the hopper of the machine, while another adds the appropriate amount of water to the mix. Another person pushes the material into the shaping chamber and forces the brick material out of the forming die and onto the cutting table, and they the bricks are dried and usually fired.
Not everyone likes the rougher look of wired bricks, and their more porous nature means that they aren’t necessarily as appropriate for all types of building projects. Circumstances that require more strength might use wire bricks as a decorative outer layer to give the look of a brick structure but a core made of something else.