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CSDA Contractor Installs UNESCO World Heritage Medallion at Fallingwater Facility

CSDA Contractor Installs UNESCO World Heritage Medallion at Fallingwater Facility

It’s not every day that a concrete contractor is asked to work at a UNESCO World Heritage Site, but CSDA member Matcon Diamond of Pittsburgh, PA, was asked to do just that.

Fallingwater, known as one of the greatest architectural triumphs of the 20th century, is located in the mountains of Southwestern Pennsylvania and considered to be one of American architect Frank Lloyd Wright’s best-known designs. Commissioned by Pittsburgh department store owner Edgar J. Kaufman, Sr. in 1935, Wright designed Edgar and his family this private residence, which combines an ideal fusion of art and nature. Fallingwater is built over the waterfall for which it is named and was donated by the Kaufman family to the Western Pennsylvania Conservancy in 1963. It operates today as a museum and nature reserve.

Matcon, who had previously worked on several projects for Fallingwater, was pleased to be asked to do another. This time, the plan was to install a UNESCO medallion into the facility’s sidewalk.

During the 2019 meeting of the World Heritage Committee, “The Architecture of Frank Lloyd Wright,” was added to the UNESCO World Heritage List due to its outstanding universal value and organic representation of architecture (open plan, blurring of exterior and interior boundaries and the modern use of steel and concrete). Each site on the UNESCO World Heritage List is presented with a medallion to display on its property. 

For this job, Matcon decided to core drill a 32-3/8” diameter hole, 2” deep into the existing 8” thick exposed aggregate sidewalk slab. Once that was completed, a diamond-cut would need to be made inside the core hole’s footprint so that the concrete could be chipped out to its desired level. Lastly, after the installation of the grout bed, the UNESCO medallion would be inserted into the sidewalk. 

During the project, the Matcon team learned that the sidewalk around the entire facility had recently been replaced with a decorative exposed aggregate finish. In order to eliminate the risk of mismatching the finish, a panel would have had to be replaced entirely. This, along with the threat of the inset detracting from the medallion, made Matcon go back to the drawing board. 

Thanks to Superintendent AJ Waldor, Matcon came up with a solution to modify a 30” core bit to accommodate the medallion’s required size. The in-house fabrication shop took 1/8” by 8” flat steel and rolled the piece to the rough diameter of a 32-3/8” hole. Matcon then welded a series of square stock spacers at set positions around the outside of the 30” core bit. After that, the 8” rolled piece was welded to the square stock where it was raised from the drilling surface of the 30” bit by approximately 1”. This allowed them to utilize the drum of the 30” bit for centering the guide plate. 

Since the owner didn’t want anchor holes in the sidewalk, Matcon fabricated a guide plate that could be mounted to the concrete sidewalk, within the footprint of the core hole. Once the diamond cutting and drilling were completed, the anchors were removed along with the rest of the material needed to create the medallion pocket. Then, the guide plate was outfitted with stems to accept three Diamond Products concentric rollers.

To create a clean and sharp cut kerf without damaging or removing any exposed aggregate stones, Matcon needed to get some obscenely soft segments. To do this, they contacted K2 Diamond, who worked with their metallurgist to create a solution for Matcon. Two days later, the fabrication shop brazed a series of K2 Diamond Superman segments to the outside ring at a dimension that would precisely create the 32-3/8” kerf. After a few test runs of drilling into the shop driveway and making slight tweaks to the outside band, Matcon was confident they had created the perfect bit for the job. Matcon mounted a hydraulic core motor and stand to their Diamond Products CC8000 Rider Saw and headed to the Fallingwater facility.

“Having worked on Fallingwater on and off throughout the past couple of years, we have a great rapport with the facilities management staff. This project was special to us since it celebrates not only Frank Floyd Wright’s contributions to American architecture but to the whole world during the 20th century,” says Dan Matesic, Operations Manager for Matcon Diamond. “It was a huge honor to be a part of it.”


Matcon Diamond was founded in 1985 by Dave Matesic with an F-150 pickup, a 65 HP saw and a lot of grit and determination. Since their inception, they’ve grown to over 50 employees with as many trucks (and even more custom saw gadgets that they’ve created). Matcon offers a full range of concrete sawing, drilling and removal services throughout Pennsylvania. They have been CSDA members since 1987. 


Cutting Contractor

Matcon Diamond

Contact: Dan Matesic

Tel: 412-481-0280



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