“As functional as it is beautiful,” was how Dr. Robert Feirsen, superintendent of Garden City, New York, schools, described the polished concrete used in the new addition and renovation of the city’s middle school.
Garden City Middle School, originally constructed in the early 1900s, was in need of an expansion and overhaul. Included in the project was the architectural firm’s design and vision to use polished concrete floors. The school and architect wanted to create a cohesive flow and feel of consistency to ensure the new addition and areas to be renovated kept the same feel as the original building.
Green Earth Floors of Tuckahoe, New York, was awarded the 7,500-square-foot polishing portion of the project. Matt Johnson, company owner, decided to use Husqvarna’s Hiperfloor concrete polishing system which increases the floor’s durability and strength, while enhancing its beauty and reducing maintenance costs.
“The floor was sort of a kibosh of different things and I thought Husqvarna’s full system with a grout coat was the way to go,” he says, as the grout would fill the many air voids in this particular floor. “I wanted to use a complete system from start to finish.”
The first major obstacle that Johnson and his team of artisans had to overcome was how to create a seamless blend between the existing and new concrete. They solved the problem by grinding the new and existing surfaces to the same aggregate exposure and dying the surface with a 20 percent gray from Ameripolish’s Classic line at the 400-grit level to make the surface a uniform color. They then stained the concrete in the school’s colors, maroon and gray, which had to be custom blended.
“After achieving the color we wanted, we brought it up to 1,500, put a stain guard on it and burnished that with a 2,500 twister pad from HTC,” Johnson says.
The second major obstacle involved new concrete that wasn’t placed according to specification, so the slab was as hard as a porcelain plate. Because of the extremely hard concrete, the Green Earth Floors team had to complete more steps than anticipated.
“We had to grind the floor with much softer diamonds than we anticipated,” Johnson says, adding that they even used something called Slurry Slayer. “It’s almost like an etching product. You spray it and let it set and then cut it with diamonds.” To be able to cut into the hard surface, more aggressive 40-grit diamonds had to be used. In addition, Husqvarna GM3000 grouting system was applied to fill in the pinholes on the concrete surface.
Even with the unexpected steps, the operator was able to grind dry and stay on schedule. The Green Earth Floors team stepped up to the challenge and succeeded in meeting the architect’s vision. When the project was completed, the polished concrete was visually striking and the main feature of the school’s entrance.
Project at a Glance
Client: Garden City Public Schools in New York
Contractor: Green Earth Floors of Tuckahoe, New York | www.greenearthfloors.com
Scope of project: Polish 7,500 square feet of flooring in a school built in the early 1900s
Products used: Husqvarna’s Hiperfloor concrete polishing system including Husqvarna GM3000 grouting system, Ameripolish Classic dyes in various colors, Slurry Slayer