Ever walked into a building and got captivated by the smooth glossy floor or wall covered with aesthetic patterns and drawings of all sorts? Or maybe, you saw the same kind of finish elsewhere on a friend’s kitchen countertop you once went to visit. You were then left to wonder “what is that that was used to achieve such an attractive finish?” Well, your search has led you to the right place. The material used most likely was terrazzo.
This article will be a quick guide for you to understand what this terrazzo material really is, and maybe you might just decide to use it in your home or suggest it to your client in your next construction project as a contractor.
What is Terrazzo?
Terrazzo is derived from the Italian word for ‘terrace’. Terrazzo is a composite material made up of stone chips like marble, glass, granite, quartz, shell and most recently, plastic, mixed in a binder such as portland cement or epoxy matrix. The mixture can be pre-cast and later placed where required or prepared in situ. After being poured, the mixture is left to cure, ground to smoothen the edges, and finally polished to produce that smooth finish.
The History of Terrazzo
Terrazzo was discovered by the Italians more than 500 years ago. Venetian marble workers decided to take broken pieces of marble left after construction works and make use of them in their homes. They mixed the broken pieces of marble with clay, levelled it out and left it to dry. After realising the surface was too rough to comfortably walk on, the workers used rubbing stones to smoothen out the surface. The smooth surface was then comfortable to walk on.
Though the surface was now smooth, it still lacked the intended aesthetic appeal of marble. This was because the marble would get hidden under a ‘fog’ caused by the grinding to smoothen the surface. Luckily, a discovery on how to clean the terrazzo and expose the shine of the surface was made, helping boost the reliability of terrazzo as a flooring surface.
Terrazzo was then introduced in the United States in the early 1900s. Wealthy Americans adopted the technique thus making the technique go further globally. Further improvements that benefitted the increased use of terrazzo occurred, such as; electric grinders that provided better quality finishes at a lower cost and brass divider strips that allowed for more artistic creations.
A notable building where terrazzo was used in the past is the St. Peter’s Basilica. Renowned artist Michelangelo was appointed by the then Pope in 1546 to design the building’s floors, which to date have maintained their impressive appeal.
How Terrazzo is made
As you now have an idea of how terrazzo was made in the past, let us take a look at how terrazzo is currently made.
The basic concept of preparation of terrazzo has not changed much over the past years. Chips of marble, glass, quartz, shell, granite or plastic are mixed with a cementitious binder such as Portland cement or an epoxy matrix. They are mixed in a mixer at a particular ratio, usually 2:1 (2-part aggregate and 1-part binding mixture), with water added to assist combine the aggregates. More than one of these aggregates can be used in a single mixture. At times, sand will be incorporated into the mixture.
After proper mixing, the mixture is poured onto the required surface, levelled out and left to cure. After drying, the surface will be ground by an electric grinder to smoothen it and polished to provide the ‘shine’.
Characteristics of Terrazzo
- Non-porous, thus resistant to moisture.
- Mould resistant due to being resistant to water.
- Easy to clean because of being smooth. However, solvent-based cleaners shouldn’t be used as they will stain the terrazzo surface.
- Aesthetically pleasing when well done – When professionally done, intricate designs and patterns can be produced that are quite attractive to the eye.
- Durable/long-lasting.
- Easy to maintain – The surface doesn’t require regular polishing to keep it shiny.
- Environmentally friendly – The chips used are naturally occurring materials and thus don’t harm the environment. Terrazzo can also be recycled thus reducing its contribution to waste production.
- Colourful – The chips used come in all colours thus increasing the aesthetic range. The cementitious binder colour can also be changed to help achieve the perfect blend of colour with the marble chips.
- Versatility – Terrazzo is not only used as a flooring solution. It can be used on staircases, walls, and countertop surfaces. The material is also used by the art industry to produce various artistic items.
- Can be repaired – In an instance where the terrazzo develops cracks or bits of it chip off, the damaged area can be repaired by patching the area with a mixture of the same aggregate type, and with a similar aggregate binder ratio as the current.
- Terrazzo is a poor conductor of heat and thus will feel cold to the touch during the cold seasons.
Types of Terrazzo
Terrazzo is classified according to the binder used to mix the aggregate. Terrazzo is therefore classified under two categories; cement-based terrazzo and epoxy-based terrazzo.
1. Cement-based Terrazzo
- Sand cushion Terrazzo – This type of terrazzo is the most common interior flooring option used in areas with high traffic and high surface friction. This type of terrazzo is installed by first creating a recession of around 3″ in the concrete slab. A layer of sand, around 1/8″ is then placed. An isolation sheet is then placed over the sand, which acts as a base for the galvanised wire mesh placed on top of it. This wire mesh holds the sand cement under-bed of the terrazzo. Divider strips are then placed at regular intervals between the sand cement under-bed and the terrazzo topping to be poured. These strips prevent contraction of the terrazzo, hence avoiding cracks, and also enhance the aesthetics of the colours by creating division lines between differently coloured terrazzo. The terrazzo topping applied is usually 0.5″ thick.
- Bonded Terrazzo – Bonded terrazzo can be used in interiors as well as in exteriors. To install, the concrete slab needs to be depressed by 1.75″. A sand cement under-bed is prepared and poured to bond with the concrete slab. A terrazzo topping of 0.5″ thickness is then poured to bond with the under-bed. The under-bed indirectly assists the terrazzo topping bond with the concrete slab.
- Rustic Terrazzo – Also referred to as washed terrazzo. The rough exterior gives it a rustic feel and hence the name. Its rough surface, unlike other terrazzos, makes it slip-resistant making it a perfect solution for outdoor spaces such as swimming pools, walkways, and patios. A depression of 2″ is required in the concrete slab it is to be placed. A sand cement bed is then poured followed by the 0.5″ layer of terrazzo topping. The cement binder used is similarly textured.
- Monolithic Terrazzo – Monolithic terrazzo is known for its budget-friendliness. This is due to its quick installation time. The terrazzo mixture is poured directly on the concrete slab without the need for a depression. However, a bonding agent is applied between the concrete slab and terrazzo mixture to properly bond the two surfaces.
2. Epoxy-based Terrazzo
- Thin-set epoxy terrazzo – Here, the aggregates are mixed in an epoxy matrix and poured onto the concrete. Being around 1/4″ to 3/8″ thick, the product is a light flooring with a smooth, shiny and luxurious finish. When applied, the mixture quickly dries and can be ready for polishing a day after application. Epoxy-based terrazzos are better in terms of aesthetic versatility as numerous designs and patterns can easily be obtained.
Applications of Terrazzo
In construction, terrazzo has a fairly wide range of uses but mostly serves as an aesthetic finishing material on surfaces. It is used as;
- Flooring solution – Instead of the usual ceramic tiles, red oxide or wood flooring, one can opt to use terrazzo as an alternative. This applies to staircase flooring as well. When first used, it was mostly used in commercial spaces such as offices. Over the years, it became a common flooring solution in many other areas such as hospitals, banks, learning institutions, airports and hotels. It is a perfect floor finish, especially the epoxy-based terrazzo, for hospitals due to its characteristic nature of being mould resistant and easy to clean. Therefore, the chances of bacteria and other dirt-related infections being spread within the hospital are greatly reduced.
- Wall finish – Terrazzo can likewise be used as a wall finish, especially where aesthetics come into play. A good example is when it is used as a backsplash in kitchens to provide an aesthetic appeal and functionality of being a water barrier against the wall.
- Countertops – Just like granite countertops, terrazzo provides the functionality purposes of being durable and easy to clean. Its aesthetics also help beautify the kitchen space just as you would like. All these while being cheaper than marble and granite.
- Outdoor solutions – Due to its durability, terrazzo can be used to create outdoor furniture such as benches in parks. The furniture is easy to clean since it doesn’t take in the dirt that lands on it, thus the furniture can be used more often. Swimming pools, garages and walkways are also outdoor areas finished with terrazzo e.g rustic terrazzo, to provide that rough texture that serves its purpose.
Outside construction limitations, terrazzo is used artistically to create jewellery and 3D wall art installations. A versatile material indeed. Now, to the pros and cons of this material.
Advantages
- Mould resistance.
- Water-resistant.
- Life-long durability.
- Easy to clean/maintain.
- Visually appealing.
- Environmentally friendly as it is recyclable.
- Repairable when damaged.
Disadvantages
- Requires professionals to install – The application and installation of terrazzo require professionals to achieve the best of the material. This is especially when patterns and artistic designs are to be produced on the surfaces.
- Relatively expensive – The process of installing terrazzo is quite costly, but, most people don’t mind paying the extra dollar due to its assured life-long durability.
- Slippery when wet – Since it is non-absorbent, water will remain on the surface and pose an injury risk should one step on it.
Conclusion
Deciding to use terrazzo as a finish in your house, office, hospital, or wherever you see fit, is not a bad idea. The durability and aesthetic quality it offers, especially from the epoxy-based terrazzo, is quite enough to make one opt for it over ceramic tiles, granite tiles and maybe wood.
Therefore, I hope this quick guide has helped you understand terrazzo and all the amazing aspects it offers.
