What is Terrazzo?

We recently had an order for terrazzo tiles, but do you know what terrazzo is really?

Terrazzo is a composite material, poured in place or precast, which is used for wall and floor coverings. Traditionally it consists of marble, quartz, granite, glass, or other suitable chips poured with a binding agent. Terrazzo is cured, then ground and polished to produce a smooth, uniformly textured surface. Terrazzo is thought to have been invented by Renaissance Venetian construction workers as a low cost flooring material using marble chips left over from cutting expensive solid marble. The workers would set them in clay to surface the patios around their living quarters. Consisting originally of marble chips, clay, and goat milk (as the sealer), production of terrazzo became much easier after the 1920s and the introduction of electric industrial grinders and other power equipment. Similar aggregate floors have been found in Turkey however and date back as far as 8000 BCE. Terrazzo artisans create walls, floors, patios, and panels by exposing marble chips and other fine aggregates on the surface of finished concrete or epoxy-resin. Much of the preliminary work of terrazzo workers is similar to that of cement masons. Marble-chip, cementitious terrazzo requires three layers of materials. First, cement masons or terrazzo workers build a solid, level concrete foundation 10cm deep. After the forms are removed from the foundation, workers add a layer of sandy concrete. Before this layer sets, terrazzo workers partially embed metal divider strips in the concrete wherever there is to be a joint or change of color in the terrazzo. For the final layer, terrazzo workers blend and place into each of the panels a fine marble chip mixture that may be color-pigmented. While the mixture is still wet, workers toss additional marble chips of various colors into each panel and roll a weighted roller over the entire surface. In the 1970s, polymer-based terrazzo was introduced and is called thin-set terrazzo. Initially polyester and vinyl ester resins were used as the binder resin. Today, most of the terrazzo installed is epoxy terrazzo. The advantages of this material over cementitious terrazzo include a wider selection of colors, a thinner installation layer, lighter weight, faster installation, impermeable finish, higher strength, and less susceptibility to cracking. The disadvantage of epoxy resin–based terrazzo is that it can only be used for interior, not exterior, applications. Epoxy-based terrazzo will lose its color and slightly peel when used outdoors, whereas cement-based terrazzo will not. In addition to marble aggregate blends, other aggregates have been used, such as mother of pearl and abalone shell. Recycled aggregates include: glass, porcelain, concrete, and metal. Shapes and medallions can be fabricated on site by bending divider strips, or off site by water-jet cutting. When the terrazzo is thoroughly dry (or cured in the case of thin-set terrazzo), helpers grind it with a terrazzo grinder, which is somewhat like a floor polisher, only much heavier. Slight depressions left by the grinding are filled with a matching grout material and hand-troweled for a smooth, uniform surface; it is then cleaned, polished, and sealed. Engineered stone as it is known in the US, is also commonly referred to as agglomerate or agglomerated stone, the last term being that recognised by European Standards (EN 14618). The Quartz version (which end consumers are much more likely to directly deal with) are commonly known as 'quartz surface' or just 'quartz'. As you can see in the photo above the agglomerate particles occur throughout the material. Terrazzo tiles on the other hand are porcelain or ceramic tiles that are printed with a design resembling terrazzo. With modern ink jet techniques these designs are absolutely indistinguishable from real terrazzo. Contact us with any enquiries about tiles.