Bob Murrell 

M3 Technologies

Photos by Bob Murrell

I come across ceramic tile projects quite regularly. Some are newer installations and some are very old. The older installations may have many years of poor maintenance practice issues such as improper coatings that have been applied through the years, sometimes for decades or longer. Many times, the coatings are slathered all the way up to the base or cove molding as well.

Recently, I assisted Knoxville Marble Polish with restoring an estate home built in the early 1900s by a local tile shop owner. This is the second or third house built by the John Beretta Tile Company family that KMP has helped restore.

 John Beretta Tile Co was established in 1914 and imported tiles from Italy, Spain, and other countries from around the world. They installed their tiles in many residences, local businesses, and landmark institutions like the Bijou Theatre in downtown Knoxville.   

The home we worked on for this particular project was built in the early to mid 1920s, probably around 1925 or so. As usual, the John Beretta Tile Company installed plenty of fanciful tiles from around the world. There are cotto or terracotta tiles, clinker tiles, glazed tiles, and even hand painted tiles on the flooring as well as vertical surfaces. My friend and ceramic engineer, Bob Simpson, says that the hand-painted tiles are probably from Portugal, as they were very popular during the early Twentieth century, and most likely were quite expensive at the time.     

Cotto or terracotta (translates from Italian as “baked earth” tiles are created from particularly porous and easily shaped clay with a high iron content. This high iron content gives the tiles their characteristic reddish and brown colors. They are fired at relatively low temperatures, around 600 to 1,000 degrees Fahrenheit. These earth-toned tiles are very desirable, but due to their porosity (unless they are glazed) and surface texture, require some sort of sealer to protect them from soiling and staining issues.

There were also clinker tiles in some of the flooring surfaces. Clinker tiles differ from terracotta tiles as they are vitrified. The vitrification (from the Latin vitreum, meaning “glass”) process takes these tiles to a much higher heat level than the terracotta tiles. The vitrification process transforms the clay material of the clinker tile into a non-crystalline amorphous solid, which helps with the impermeability of water to the tiles. Vitrification is usually achieved by heating the material until it liquidizes and then cooling rapidly so that it forms a glassy solid.   

The hand painted tiles, which were geometrically scattered throughout the terracotta floor, were probably of Portuguese origin, or quite possibly Spanish. There was also an Azulejo-type  tilework on the wall in the entrance vestibule. Azulejos were typically a tin-glazed ceramic tilework found on the interior and exterior of churches, palaces, schools, government buildings, and upscale houses. They were not only used as an ornamental art form but also had a function — temperature control in the building.

There were also many glazed tiles used throughout the tile floors, walls, and features. Specifically, there was a water feature on a wall in the sunroom. This fountain was covered with years of mineral buildup and rust. Of course there was also old wax and sealer on this, just like all of the other tile surfaces, too.

There was literally 50-plus years of waxes and sealers on most all of the surfaces in the home. This included the terrazzo foyer and the concrete staircase leading to the second floor. Some quarry tiles were used in a fairly new remodel of the laundry room, located off the kitchen, which also had a floor finish that had accumulated for several years. 

To refinish all of these tile surfaces, most of which had fairly wide grout lines, stripper and brushes were necessary to get into the grout. Multiple applications of the stripper, in combination with hot water and brushing agitation were required. 

On the flooring surfaces, a medium nylo-grit brush was used under the rotary machine. One 25-pound weight was used on the machine for additional down pressure. In the corners, stubborn areas and features, a stainless grout brush was used, by hand.

After it was determined that the coatings had been effectively removed, Majestic Deep Cleaning Stripper/Degreaser and Majestic Heavy Duty Tile & Grout Cleaner (a mild acid) were used to remove any remaining soiling as well as staining or discoloring in the grout. These were also done using the nylo-grit brush and the floor machine. The Heavy Duty Tile & Grout Cleaner was very effective at removing rust, oxidation, and discoloring. The acid basically removes these issues by exfoliation. Once these surfaces were completely stripped and clean, Majestic No-Rinse pH Neutral Cleaner was used to effectively neutralize the surfaces and remove any of the heavy cleaner residues.

The terrazzo foyer and concrete stairs had to be honed to remove any old coatings and restore consistency. The stairs required stripping and honing to remove the years of finish and waxes that had been applied. The terrazzo foyer was honed with Triple Thick 220 grit and 400 grit diamonds, and finally polished with Majestic 5X Gold and a natural hair pad. Border edging was completed using 220 grit and 400 grit AA5 Turbo resins on a Makita slow speed right angle hand tool, prior to each grit on the floor machine. Stairs were honed with a 400 grit ELF electroplated metal-bond diamond.

At the request of the homeowner, a matte finish topical sealer was applied to all of the tile, grout, and concrete stair surfaces once everything had sufficiently dried. About three applications of the sealer were eventually applied. Nothing topical was applied to the terrazzo.

The tile, concrete and terrazzo surfaces all turned out looking very good. The contrast between the before and after was very sharp. This was another historic and unique home project that was completed with outstanding results.

As always, I recommend submitting a test area to confirm both the results and the procedure prior to starting a stone or hard surface restoration or maintenance project. Also, the best way to help ensure success is by partnering with a good distributor. I have worked with Braxton-Bragg for many years. They really know their products and 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 currently the Director of Operations for M3 Technologies.