Like every fashion trend, old revolves around to come again as new and quite similarly, the 16th-century terrazzo flooring is now making a great comeback in commercial flooring segment. The word ‘terrazzo’ comes from the Italian word for ‘terrace’. An idea born out of frugality, terrazzo descended directly from Rome when ingenious Venetian mosaic workers unearthed a way to reuse the marble remnants. They pressed these castoffs into a clay base, ground and then polished to expose the hidden chips, and that was the birth of astonishing terrazzo. The clay was then replaced with cement and since then, the terrazzo floors, recognized for its glimmering beauty, started enticing architects all over the world. The National Terrazzo and Mosaic Association (NTMA) defines terrazzo as: ‘Terrazzo consists of marble, granite, onyx, or glass chips in Portland Cement, polyacrylate Portland Cement, or resinous matrix binder. The terrazzo is poured, cured, ground, and polished. Terrazzo is typically used as the finish for floors, stairs, or walls.’ The unmatched elegance and the incredible durability of terrazzo have helped the old technique survive till today.
Limitations of cement based terrazzo
But by the mid-1970s terrazzo fell out of fashion, paving way for carpets and tiles. The fall out of terrazzo floors from the contemporary world was due to the numerous inadequacies of cement terrazzo floors. Cement terrazzo provided very dull and predicted patterns and the mosaic effect with limited colour options were no more appealing to the consumer. The floors were getting easily stained and there were numerous cracks appeared on the floors. The chips and glass pieces were started coming out of the floors because of the poor bond strength of cement as a binder. The thickness of the floors was above 50 mm and the weight was over 100 Kgs per sqm, raising concerns of dead weight to the structures. Moreover, the installation took weeks and months, as cement mortar gained its strength only after 28 days. Moreover, the natural wear and tear of frequent traffic made marks and scuffs on the surface, thus losing its sparkling nature over the time.
Epoxy Terrazo: Cerrazzo
A few decades ago, epoxy replaced cement as binder and the high strength polymer technology has pushed terrazzo back into the spotlight again. Today the use of thin-set epoxy terrazzo has provided all of the long lasting beauty of traditional cement terrazzo and at the same time brought the advantages such as vibrant colours, unlimited pattern designs, protection from cracking, non-staining surface and quicker installation. Cerrazzo is non porous and can be tinted to match any colour scheme. Epoxy terrazzo is chemically resistant and more flexible than its predecessor while offering higher compressive strength. Table 1 gives the comparison of properties of cement and epoxy terrazzo.
Features of epoxy terrazzo
Unlike traditional flooring materials that require stringent processes and specific chemicals for their upkeep, terrazzo is generally very easy to maintain. Its gloss and sheen continue to shine through for the ages to come, giving the floor an incredible luminance and unblemished appearance. There are no joints where dirt can accumulate to spoil the look. Further, Cerrazzo is non-porous and crack-resistant and requires daily maintenance of only dry?mopping, thus saving water, electricity, and manpower. Maintenance of extremely?high-use areas requires only neutral PH cleaners and water.
Cerrazzo withstands the lifespan of the building, making it one of the most durable materials available for designers and architects. Very minimal repairs are only needed for terrazzo making it a cost-effective option as well. So, 40+ year lifespan of Cerrazzo beats the most widely used interior flooring systems hands down.
Colour and texture continue to exert a strong influence on user perceptions. Cerrazzo gives designers the option to use any colour or shape they wish to create. The number of aggregate options and combinations is staggering with traditional marble and granite chips of all colours and sizes, recycled and virgin glasses, recycled mirror glass, tinted windshield glass, bottle glass, plate glass and recycled porcelain. Metal scraps, from brass screws to aluminum shavings to chunks of zinc can be used in Cerrazzo. Mother of pearl can add beauty to a terrazzo floor, even as low as 5% of the aggregates. Any shape, from curvilinear artistic patterns, to geometric shapes, intricate logos and artwork, to simpler single colour monolithic, strip-less floors is achievable in Cerrazzo. Imagination is the only limit in designing Cerrazzo floors.
Air quality and off-gassing
Consumers are becoming more aware and concerned about the off-gassing habits of the products they use in their homes and places of business. The components of Cerrazzo have zero-VOC materials, with little to no off-gassing. The non-porous, cleanable surface of Cerrazzo does not support microbial growth, which leads to enhanced indoor air quality.
Thinner and lighter
Thin-set Cerrazzo is thinner and lighter than other flooring systems. Cerrazzo has an average 6-8 mm thickness and weighs around 16 Kgs per sqm, where as other floorings can weigh as much as 120 Kgs per sqm, with a thickness of over 50mm.
Non-porous & non-staining
Cerrazzo is smooth, seamless, and non-porous and as a result, it is easy to clean and maintain. The hard and non-porous characteristics of glass, along with the seamless nature of terrazzo discourage bacterial growth and resist all sorts of stains.
Sustainable floors & LEED points
With the recycled content as high as 85%, Cerrazzo is a sustainable flooring. The regional sourcing, durability, indoor air quality, use of commercial wastes from factory cast-offs can help a facility going for Cerrazzo achieve LEED certification. The extreme longevity and low energy usage required for maintaining Cerrazzo floors grants them highly favourable embodied energy for their life cycle, meaning the energy used to create and sustain them is lower than other flooring options. Since 85% of the product is recycled material, this has a significantly positive impact on the environment. The ability to use the materials meant for landfill? means minimal?transportation impact and therefore minimal greenhouse gas emissions. Cerrazzo flooring can contribute to the achievement of project LEED certification goals for its users in areas such as building re-use, recycled materials, innovative design and regional materials. The Table 2 is a representation of LEED 2009 for new construction and major renovations, and
LEED 2009 for commercial interiors and the possible points available.
Cerrazzo floorings are predominantly employed in commercial segments in US & Europe, specifically in airports, commercial spaces, restaurants, cafeteria, casinos, museums to name a few. Dallas International Airport, the fourth busiest airport in the United States, with more than 65 million passengers passing through the facility, was floored by thin-set epoxy terrazzo for an area of over 5 million sqft. Similarly, at the Cleveland Hopkins International Airport, more than 10000 square metres of black carpet were replaced with epoxy terrazzo. One can walk across huge areas of terrazzo floorings at Las Vegas’ McCarran International airport. Recently, over 1 lakh sq mtrs of terrazzo floorings were installed at Qatar airport.
The installation of Cerrazzo floor system is an art in itself and the skills involved have been passed down from generation to generation. Surface preparation is necessary as a first step to prepare the substrate for a strong bond to the terrazzo system. This is achieved by shot blast machines or scarifiers to provide a surface with the appropriate CSP profile for a good anchoring of terrazzo system. Crack detailing is necessary to ensure that the fractures in the concrete substrate are not transmitted upwards into the terrazzo floor topping, which is achieved by the use of a flexible epoxy product called CrackFill or Episeal. A solvent-free epoxy is applied as a primer in order to achieve a strong bond between the substrate and the terrazzo. The next step is to lay down metal strips to create the desired geometrical design on the floor. These strips are aluminum, brass or zinc and used for colour separation in floor design, as well as the layout of patterns. In addition to creating a design feature, the transition strips also help to satisfy the structural requirements of the substrate and strengthening of the control joints. The terrazzo mix is prepared by mixing Cerrazzo resin and hardener with decorative aggregates. The Cerrazzo mix is then trowelled by hand or with use of a power trowel and left for curing for overnight. After 24 hours, the terrazzo achieves a compressive strength of 70 MPa (100-110 MPa in 3 days) which is quite adequate to start grinding and polishing process. Grinding of the floor is done with HTC or similar machines which circulate around a dozen diamond stones at a high speed. The grinding process begins with rough stones and then graduates to smoother stones throughout the process. After the first cut, grouting is done with solvent-free epoxy to block the pores. After a day, the surface is polished using various types of polishing stones and pads.
First cost and life cycle
While Cerrazzo’s high first cost has traditionally discouraged consumers, but now people realise that the life cycle performance should be weighed upon while reviewing initial cost. Many people appreciate that reduced operational costs over the floor’s lifetime do ultimately improve their facility, the bottom line and better return on investment. Thus Cerrazzo is making a comeback based on its longevity, low maintenance requirements, and the ability to incorporate recycled materials.
The insitu Cerrazzo, with its unique appearance, timeless beauty, durability, green building features, and endless designs, is becoming a popular choice for commercial buildings of all types, and is now expanding into the residential market in the US and European countries. With all of these attributes, we can very well anticipate that Cerrazzo will create waves in the floor covering market in India very soon. Terrazzo gives you the best of the world’s: stunning designs, unparalleled durability and environmental sustainability. Today, the terrazzo floorings, once meant for kings and queens, will now be available to everyone.