Ideally, a polished concrete floor starts with a poured concrete slab—but this home was slated to have hardwood floors. Halfway through construction the homeowners decided they wanted polished concrete.
Cuviello Concrete was contracted by manufacturer Concrete Collaborative to install their seamless architectural concrete flooring into the first floor of the home, which consisted of 2100 square feet of area. Adding to the already tough site conditions, floor register heights were set and anodized aluminum sliding door frames were already in place. The challenge was to come up with means and methods to place and polish not only against the anodized aluminum, but also over a primarily wood subsurface.
First, the polishing contractor had to devise a system to create a concrete base on top of the existing plywood subfloor. This was accomplished with a series of lifts that reinforced the floor and gave it enough depth for polishing. Cuviello Concrete poured two 3/8-inch lifts to add strength, help prevent cracking, create a level subfloor for the second pour, and bring the floor to the height of the already set floor registers and sliding door tracks.
To save money, the first lift was poured uncolored. It also included SpiderLath to help reduce the chance of cracking. Before pouring the second lift, which was integrally colored, the contractor installed zinc decorative strips for both aesthetic purposes and as another means of crack control. The challenge was to bring the material to the top of the zinc strips and float the material to the top of the floor registers and sliding door tracks. The contractor taped off floor registers, door frames, electrical floor boxes, and sliding glass-door tracks to isolate them from the overlay bonded to the floor, so that any movement would not cause cracking.
The polishing crew started with a 70-grit metal and worked through each consecutive grit, making sure to fully refine each grit and ensuring maximum durability the surface would allow. To finish edges up against the aluminum anodized frame, the crew covered all the frames with blue painter’s tape, which is thin, so edges could be finished to a zero tolerance.
The edges took more time than the actual polishing of the main body of the floor.
The floor was brought to a 1500-grit resin. The whole process was done dry, with the crew doubling up on vacuums and using an air scrubber to capture all dust. When the process was complete, the floor was covered with an 18-mil, felt-backed poly; the protection withstands heavy construction, and lifts and job boxes can be rolled over and stored on top.
The final result is a stunning floor with zinc joints that gives the home a very unique look and feel.