EASE OF MAINTENANCE

Another commonality shared by both epoxy and sand-cushion cement is the fact that they’re both extremely durable and low maintenance like all terrazzo systems. Since terrazzo floors are solid surfaces, if they are prepared and installed correctly, and if adequate room is allowed for potential future movement, they are resistant to cracking and breakage. That said, the cement-based binder used in sand-cushion terrazzo is naturally porous and is therefore more susceptible to staining. To guard against this, a nonporous sealer should be applied over both epoxy and cement-based terrazzo installations to protect it and help ensure its longevity.

“Regular cleaning with a damp mop or soft brush and a mild cleaning solution is all that is needed to keep these floors looking their best. They do not require any special cleaning products or equipment, which makes them very convenient to maintain,” reports Biswas. Not only are maintenance costs and labor is lowered, but building occupants benefit from a cleaner, healthier environment.

Terrazzo is particularly suited for high-traffic areas, as well as both dry and wet environments, making it appropriate for kitchens and bathrooms. It’s food safe and non-slip when used with the correct sealers and finishes.

DURABILITY

Terrazzo’s exceptional durability regardless of aggregate size or matrix is evident in its toughness under damaging conditions. For example, in New Orleans following Hurricane Katrina, most of the terrazzo there required nothing more than polishing and refinishing, according to Alton Davis, with Richard C. Lambert Consultants, Mandeville, La., who led the architectural team on the $17-million restoration of Lakefront Airport terminal. “Katrina just reemphasized what I already knew about terrazzo,” Davis says. “When they tear down the building, it will still be there. If the building lasts hundreds of years, the terrazzo will last hundreds of years.”

Historic installations throughout the country further illustrate the value of using materials that last. When four historic courthouses in the Pacific Northwest marked their centennials a decade ago, they also celebrated 100 years of embodied energy in their historic terrazzo floors. Putting this into perspective, no new flooring materials had to be manufactured for this floor for an entire century. Very few building materials can offer this same level of longevity. Consequently, terrazzo is considered a highly sustainable material.

“Terrazzo is a very durable, beautiful substance for buildings with high traffic,” reports Rebecca Nielsen, LLED AP, an historic preservation program specialist with the U.S. General Services Administration (GSA) in Auburn, Wash. She oversees 20 historic register federal buildings in the Pacific Northwest. “Terrazzo was obviously a good choice because 100 years later we are still using it,” Nielsen notes. “On the whole, these floors are in really great shape and look great. We feature them and maintain them. We are proud of them.”

BEST PRACTICES

Due to the highly specialized nature of terrazzo projects, onboarding the terrazzo contractor early in the design process is essential to the project’s success. “When the contractor is brought on board at the point of material selection, designers can collaborate on the design aesthetic, including aggregate size and jointing, while establishing a realistic budget for the project,” says Tricia Ebner, AIA, director, MdeAS, New York City.

A local contractor also offers the advantage of producing samples to help dial in aggregate selection. “Availability and sourcing limitations of the raw aggregate material can play a major role in the final aggregate mix design, so understanding these sourcing limitations early in the design process, whether regional or national, is important, particularly if the terrazzo floor will play a primary role in the building's material palette,” notes Barwick.

Contractors also play an important role in advising on constructability and making sure the drawings are specified correctly. If the drawings and specifications are correctly listed, this avoids gaps in scope that can create issues further into the project.

The terrazzo installation can impact the building’s structural requirements—yet another incentive to work out all the details with the contractors as early as possible. With the contractor’s early involvement in a Palladiana terrazzo project, designers and architects have the opportunity to learn about the different techniques to fracture the aggregate pieces that will create a variety of looks. As noted, the contractors can also assist with Palladiana stone selection, sizing, and spacing. Other important issues to discuss with the contractor include spacing of the joints, detailing, and juncture of the vertical and horizontal surfaces.

Whereas many finishes in a building are produced in a controlled environment, terrazzo is unique in that the labor-intensive installation process is performed on site. If precast terrazzo is specified in the design, it must be fabricated inside a proper terrazzo shop. In either case, working with a highly qualified and experienced terrazzo contractor is very important. “Because the installation process can be messy, many contractors prefer to install before other finishes are brought on site. They can then come back for final polish after the remaining elements like cabinets, paint, trim work, etc., are completed,” notes Wilkinson.

To ensure essential quality assurance, selecting an NTMA terrazzo contractor member is highly recommended, says Hedges. “NTMA is a very useful resource and can provide feedback and answer questions regarding what type of terrazzo assembly is most appropriate for a given application," adds Barwick. “Standard terrazzo is a specialty product and the larger aggregate terrazzo is an even more specialized product,” notes Maraldo. “The involvement of an NTMA contractor as early as possible will make sure that the terrazzo is installed to the highest quality. Terrazzo will last the life of the building and is often a focal point of the design. Not having an experienced and qualified contractor could provide a substandard installation, which will create problems during the installation and throughout the life of the product."

Another important ingredient in a successful large aggregate project is mock-ups. For highly customized installations like Palladiana, Janet Lina, associate at Architecture Plus Information, says, “Contractors should be required to provide mock-ups to ensure that the right mix of materials is used to achieve the design intent.” Essentially, the mock-up process is an important strategy to confirm that the client’s expectations have been met, ultimately preventing unexpected costs and delays. While design teams may be tempted to rely on a small sample, this is often an insufficient way to envision the full picture of what the final terrazzo installation will look like. “Mock-ups are so important!” exclaims Michiels. “In most cases, terrazzo is not an off-the-shelf product; it is the work of artisans.”

In conclusion, the case for early terrazzo contractor involvement—from concept to completion—is strong. Offering some advice, Michiels states, “Work with these contractors to understand what they do and to help them understand what you are trying to achieve. Making terrazzo is a highly specialized craft, developed through years of experience. Good terrazzo contractors are artisans, capable of working with designers and clients to achieve beautiful work.”

IN SUMMARY

While terrazzo projects, in general, are anticipated to increase, experts predict that large aggregate designs will comprise a strong portion of this work. “The design pipeline certainly has a decent amount of larger aggregate terrazzo, so I expect you’ll continue to see this style of terrazzo for years to come,” confirms Hedges.

“Large aggregate terrazzo offers a diverse selection of design possibilities that can be made a reality with improved manufacturing methods and sustainable materials,” agrees Biswas. “As architects, designers, and clients gain an appreciation for the creative capabilities of this sturdy and dependable material, it is certain to be a popular choice for projects in the near future.”

Wilkinson believes the flexibility of Venetian and Palladiana is enticing to designers who are looking for something more than a cool tile lay. “As long as there are specialty trades who can support the installation, I think this is a product we will continue to see employed in hospitality, residential, and luxury commercial spaces,” she predicts.