The architect’s layout for this floor was circles on top of circles with a variety of stain colors in the intersecting areas. Polished & Decorative Concrete, of Kansas City, Kan., cut the circles and polished the 15,000 square feet of this elementary school. “The project was planned to be polished from the start but originally at a deeper grind,” says company co-owner Anthony Portillo. “But then the owner decided they wanted a salt-and-pepper finish.”
Despite a few imperfections from trowels and finisher footprints, Portillo’s crews were able to meet the owner’s expectations. “It was flat enough when using the Prep/Master STI-3038 which has great flex in the head so it will polish floors that aren’t perfectly flat. We did the initial grind wet; after that we did the staining and then polished it dry.”
The designs were achieved by sawcutting overlapping circles and half circles in hallways, large rooms, and doorways using different-sized templates made from Masonite and Engrave-A-Crete’s center pivot attached to a Mongoose concrete engraver and a Cobra decorative concrete saw.
“The most difficult task was laying out all the sawcuts and cutting each one,” says Portillo. “My partner and company co-owner Jon Chambers figured all that out. Each different radius had to be laid out on the shop floor and then transferred onto 1/8-inch Masonite. Over a mile of circles were cut, numbered, linked, and expanded based on their position on the blueprint. Most of the half circles were cut with a hand grinder and a steady hand.”
One issue to overcome was matching the blades to the very hard concrete floor. “We ended up using a lot of blades,” Portillo explains. “We’re used to matching up grinding grits and bonds with floor hardness or softness but not so much with saw blades. We probably went through 40 blades.”
“We tried cutting the circles both before and after the grinding but the benefit to cutting after the wet grind was that there was then no slurry in the cuts and joints, and we needed those cuts to be clean.” The final step with the joints was to install a black joint filler—VersaFlex SL/75 self-leveling polyurea joint filler.
Three stain colors were used within the overlapping circles and all the stains were completed by hand, using sponges and cut up microfiber mops. The main challenge was taking meticulous care not to mix the colors. The products used were Ameripolish dye, Ameripolish densifier, and Ameripolish SR2 stain resistor. “We believe in using a system rather than trying to mix products to get the lowest price,” Portillo says.
“The school district was happy with the results. There’s nothing better for us than a project like this where you have to jump in and figure it all out. That’s what we feel sets us apart—the ability to do detail oriented projects like this.”
