Case Studies

The 16th Street Mall in downtown Denver, Colorado, made its debut in 1982. At the time, its marquee feature was a mile-long grid of red, black and gray natural granite pavers that accentuated the mall’s modernist design by renowned architect I.M. Pei. 

Four decades later, however, drainage issues below the pavers had caused the mortar bed to deteriorate through dozens of freeze/thaw cycles, resulting in maintenance costs that were exceeding $1 million per year. Upgrading the entire installation became a top priority for a $149 million renovation effort that broke ground in 2022 and was completed in the fall of 2025. 

The most daunting challenge the project posed was its enormous scale. 

“We had never attempted a project of this size or magnitude,” said J.C. Slocum, Chief Business Development Officer for Gallegos, the stone installer. “It’s just over a mile of granite paving with just under a million stone pavers installed by our crews. This project has been a huge wish list item for the city of Denver for over a decade.” 

Lynn Randolph, Superintendent at Gallegos, described the scale of the project this way: the 16th Street Mall project involves more natural stone pavers than he has worked with over the course of his entire stone installation career combined.

Faced with the massive scale of the project, the Gallegos team reached out to Coldspring to explore whether spacers could somehow be pre-applied to the granite pavers, eliminating the need for installer to complete this step manually. 

After exploring several options, Coldspring finally landed on the automated application of innovative spacer tabs — developed internally at Coldspring — to all four sides of each paver, applied by a robotic arm to ensure absolute placement precision. This single advancement enabled the Gallegos team to install the granite pavers with the same speed and precision as the molded unit pavers commonly installed in residential applications.  

The pre-tabbed pavers proved so effective, in fact, they’re now referred to as TabStone™ and sold as part of the Coldspring standard offering, helping other clients dramatically reduce installation time on their large-scale paving projects.   

“We couldn’t have done this project without the tabbed pavers,” said Steve Kalabany, Senior Project Manager for Gallegos. “On this job, the tolerances are very high. It would have been impossible to lay these pavers without tabs.” 

The Gallegos team estimated that the TabStone pavers cut installation and quality control time in half. In addition, TabStone offers better surface friction to prevent slipping and improve pedestrian safety. Each paver is also smaller than the original pavers, which, along with an improved drainage system and updated grout and mortar underneath, will extend the pavement’s lifespan. 

Overall, the renovation involved more than 960,000 natural granite pavers. The design honors the original Navajo rug and diamondback rattlesnake pattern that has been a hallmark of the 16th Street Mall for 40 years. 

Of course, even the most talented mason will struggle to produce high-quality results without high-quality materials. This is why Gallegos selected Coldspring to supply both the technology and the natural stone for the project. 

“Coldspring is one of the most professional stone suppliers we get to work with,” Slocum said. “From shop drawings to cladding to their management personnel and operations teams, they are aligned with our values. Coldspring is the only supplier we would work with on this project.” 

The Gallegos team’s choice paid off in multiple ways. 

“Coldspring delivered exactly what the city of Denver wanted,” Randolph said. “The colors are fantastic together. And the finish is very important. If you go from one block to the next, you can’t find any differences. The material has been consistent throughout the entire job.” 

Beyond the TabStone, Kalabany added that a key reason for selecting Coldspring was the company’s unique ability to fabricate the custom curves and profiles for the largest sections of the mall. These interesting shapes are an important part of the design, because the revitalized 16th Street Mall is intended to serve as a desirable, engaging destination that draws people from throughout the community and beyond. To that end, it includes site furnishings such as tables, chairs, benches, shade structures and planters, along with play features and “moments of joy,” which are whimsical interactive pieces that include benches shaped like trout. 

“Our owner, Gerald Gallegos, always wanted us to be involved in projects that defined a city,” Slocum said. “This project makes a mark for both Gallegos and Coldspring. It’s a legacy that has our names attached to it.” 

Today, the 16th Street Mall remains an iconic and vibrant part of downtown Denver, one that will host countless visitors and a wide range of community-building activities for many years to come. 

“When we put that 960,000th piece of stone in, we felt a huge sense of accomplishment,” Randolph said.