Slippery Rock Gazette

Bob Murrell 

M3 Technologies

Photos by Bob Murrell

Terrazzo has been very popular as of late, it seems. Here in Knoxville, another well-known home was recently sold and is finally being restored and updated further. This project has been anticipated for many years and has finally become a reality. The spectacular little home is the iconic Bruce McCarty “concrete house” and has been toured by well over 60,000 people. It was built by the famed architect as part of the 1955 Parade of Homes. The structure was a system believed to never have been used in a home design before in an American residential construction project.

The brilliant design and craftsmanship consisted of a concrete roof structure, precast concrete bents, and block walls. Large aluminum-framed windows allow for ample light to enter in most all areas, front and back, of the home. Quite frankly, it certainly has the look of commercial grade construction.

Above, Left: Finished project view of the great room, with fireplace centerpiece. This mid-modern gem by famous local architect Bruce McCarty was the centerpiece of the 1955 Parade of Homes.   Above, Right: The front entry drying after a 400 grit hone. Notice the commercial grade aluminum windows and door.

Upon entering the home, the terrazzo floor and open concept of the kitchen, dining, and living areas all surround the massive, centrally located fireplace. This home is a one bedroom with a guest suite, and only 5 rooms total. With the many large windows, the home is meant to envelop you in nature, blurring the distinction between the outside and the inside. The exterior is surrounded by lush vegetation, a water feature and, of course, an in-ground saltwater pool. With the vast openness of the home, privacy is only attained with a commercial grade blind system in the windows, mainly used for the bedrooms. 

Above: Kitchen view of this light-filled space. Blending the restoration under the freestanding counters and deep overhangs was particularly challenging.   Below: The large windows blur the distinction between the indoors and outdoors in the Mid-Modern gem.

This restoration involved removing many years of finish, including a very stubborn-to-remove base coating.

The home was partially renovated by the previous owners but the dirty (and there was plenty of embedded dirt) terrazzo was saved for the current owner. There was carpet at one point during the home’s life and the tack strips were pried off with no regard to the terrazzo, so the typical blowouts from the removal were present around most of the walls. Fortunately, the client was going for a “restoration hardware” look, so the blowout holes weren’t a major concern. By the way, the wife informed me about the “restoration hardware” term and look….

So after an initial test was performed, it was determined that the floor did indeed have many years of “who knows what?” applied to it. Stripping using a conventional high pH (alkaline) stripper and black pads removed most of the dirt and homeowner finishes, but did not get the tough stuff, which was probably a durable acrylic or even a urethane coating.         

Around the edges, razor blades were used first to get the coating removal started. Then, ELF3 220 grit flexible metal bond wheels were used under the floor machine. These worked well, but even they took some time getting off the tough coating, which could quite possibly have been some of the initial coating applied by the installer in 1955!  

After the floor machine was initially run, this exposed any remaining issues with the edges. It was determined that the edges also had to be ground, and a  ELF5 220 grit with a Makita hand tool was used to accomplish this. Then an ELF5 400 grit was used around all of the edges before overlapping with the floor machine and ELF3 400s. 

Once all of the ELFs had been successfully run (or at least thought to be successful), the edges were done with an AA5 Turbo resin 400 grit. Next, the TX Triple Thick 400 grit resin diamonds were run under the floor machine. It was at this point where the reflection was high enough (starting to look pretty good, actually) to recognize there were still some isolated areas where the topical coating still existed. So the resins were halted and the razor blades and 400 grit ELFs were used again to remove any remaining coatings. This original or base coating was very tough and quite stubborn, but eventually gave in to the ELF metal bonds, and without having to drop down to a 120 grit. The ELF 120 grits were standing by just in case, though.

Now, under the overhangs of the kitchen cabinets was a sticky wicket of an issue. It was difficult to remove the coatings, as you can imagine. This was accomplished using stripper, razor blades, and 220 grit metal bond diamond hand pads. There was no physical way to reach all of the way under the free-standing island cabinets but every effort was made to blend the area underneath, with the main kitchen and entry area floors. It actually worked out quite well. 

Finally, the TX Triple Thick 400 grit resins were run again and this time the floor began to start looking good. In fact, it looked so good that polishing was tested and confirmed to work perfectly at this stage. Majestic 5X Gold polishing powder was used, first around the edges with the hand tool and a natural pad (FP-Elite-7), and then using the floor machine and a FP-Elite-20 pad. The results were very stunning and the floor looked as though it was better than new!

The clients were ecstatic when they saw and inspected the floor. It turned out much better than they had hoped for. This house was another very unique property that has a very cool history. It was such a pleasure to be associated with this project.

As always and before beginning any new project, I recommend submitting a test area to confirm the results and the procedure, prior to starting a stone or hard surface restoration/maintenance project. Also, the best way to help ensure success is by partnering with a good distributor, like BB Industries, that knows the business. They can help with technical support, product purchase decisions, logistics, and other pertinent project information.

Bob Murrell has worked in the natural stone industry for over 40 years and is well known for his expertise in natural stone, tile and decorative concrete restoration and maintenance. He helped develop some of the main products and processes which revolutionized the industry, and is currently the Director of Operations for M3 Technologies.