The Inherent Resilience of Terrazzo

Terrazzo has many qualities that make in an inherently resilient material. It is extremely difficult to damage, and it can be easily repaired. It also is designed to last. Terrazzo installations can be found where the terrazzo flooring is still in use and more than 100 years old.

Durable

Terrazzo is designed to be more than decorative; it is designed to be used. It has an incredible compressive strength. Compressive strength of a material indicates its ability to resist compression. Materials often receive a compressive strength rating, which quantifies a compressive strength limit. If a material is compressed underneath a load that exceeds its strength, some materials can fracture, while others deform irreversibly.

As it relates to terrazzo, the compressive strength of a terrazzo floor with a concrete binder is 3,000 pounds per square inch (psi), which is identical to the compressive strength of the concrete slab on which the terrazzo is installed. This means that the concrete terrazzo flooring will not be compromised before the concrete slab it rests on is. Terrazzo flooring with an epoxy binder has a much higher compressive strength and is able to withstand loads of up to 10,000 psi.

In terms of impact resistance, terrazzo, again, is a hearty solution, especially when compared with other popular materials like large-format porcelain. A porcelain tile is not fully bonded to the underlying slab when it is installed, which results in a hollow spot underneath the face of the tile. This weaker area can be more easily cracked and broken when struck. Terrazzo is not installed as a tile but is poured upon the concrete slab as a liquid, forming a complete bond with the concrete slab underneath, devoid of hollow spots that would compromise the strength of the surface.

Easy to Maintain and Repair

In addition to being difficult to damage, terrazzo is easy to maintain, repair, and restore. Imagine a terrazzo floor that has been installed in a school for 50 years. If it gets chipped or starts to look dirty, maintenance teams can simply remove the old sealers and grind and repolish the floor. In no time at all, the terrazzo floor will be gleaming as if it were brand new. The thickness of the material makes it possible to grind it down and restore the appearance of the surface. If the terrazzo floor happens to crack, it can be patched and made functional again.

In terms of maintenance, terrazzo only requires regular damp mopping with clean water and occasional resealing. Wax and polishes are unnecessary, and even harmful to the surface by creating a buildup that dulls the finish. There are special sealers available for terrazzo that can be used to enhance the appearance of the product or provide additional protection, if desired.

CASE STUDY: IVY TECH TRANSFORMATION

The original terrazzo in the sweeping monumental stairway at St. Vincent’s Hospital was reground and polished to become the stairway in the new social hub for Ivy Tech’s main campus.

It may not have been obvious, but the long-abandoned, 100-year-old St. Vincent’s Hospital located on the north side of downtown Indianapolis was the solution for space-strapped Ivy Tech Community College. The school’s enrollment had quadrupled in recent years, and it was in desperate need of more space. In 2013, the dilapidated 250-bed hospital was transformed into the Illinois Fall Creek Center, the academic and social hub for Ivy Tech’s main campus.

A large portion of the original hospital was demolished, but inside the section that had been chosen for restoration, century-old cementitious terrazzo filled the main entry and a sweeping monumental stairway. Although it seemed impossible, the original terrazzo flooring was restored and is still in use today.

The $50-million combination of restoration and new construction enabled the school and design team to conserve a treasured community landmark and its historic floors. Project architect Kevin Shelley, AIA, LEED AP, principal at Schmidt Associates in Indianapolis, explained that his favorite aspect of the project was the opportunity to save the historic building and put it back to work for the community in a new way. Preserving its historical value also translated to cost savings over demolition.

It took about four months to restore the 5,200 square feet of original terrazzo flooring in the main entryway and on the monumental staircase. Some areas were damaged or cracked and required repair and infill. Most of the old-fashioned bull-nosing on the stair treads had broken off and had to be reconstructed. Then the existing terrazzo was reground and polished, and abrasive strips were added to the stair treads. The original iron railing of the entry stairs and the two original cast-iron light fixtures were also restored.

The interior space that emerged through the renovation was amazing. “The historic monumental stairway in terrazzo—and I have no idea how they did that—stood the test of time,” Shelley says. “There was some cracking and discoloration, but we shined it up, and it was as functional and beautiful as the day it was installed.”

To complement the restored cement terrazzo in the renovated side of the project, the design team chose to install new epoxy terrazzo flooring in the entryway of the new addition, its stairway, and cafeteria dining and serving areas. “Epoxy terrazzo was the right material for the large common areas, and it met our needs with colors, patterns, and inlays,” Shelley notes.

“We did not redo the original terrazzo,” explains terrazzo contractor John Blakley of Blakley Corporation of Indianapolis. “We brought back what was there.”