2014 Education (Repair/Rehab) Winner
The concrete flooring of Jackson Senior High School’s new addition was originally stained and sealed concrete. It serves as both a major hallway to the gymnasiums and classrooms, and as a cafeteria. Every day, the staff sets up and breaks down tables and chairs for lunch. Between the heavy foot traffic from the large volume of students, and the tables, chairs, and caustic food items, the floor takes a beating.
Within the first year, the sealer started failing. During the next few years the school spent about $15,000 to $20,000 on materials and labor each summer, applying Armor Seal in an attempt to salvage the initial investment. By the end of every school year, however, the floor got worse, with the sealer peeling up more each time.
Ardor Solutions surveyed the floor and found that the sealer would easily delaminate and peel up in large sheets, taking stain with it. The contractor recommended dyed and polished concrete as a more attractive and durable alternative, since it would require considerably less maintenance while increasing the existing impact of lighting.
The floor had a very low floor flatness rating, so Ardor had to start with 30-grit metals and expose large aggregate in many areas to remove the sealer and the stain. The edges also had to be ground down to aggregate so they could blend with the rest of the floor. The joints were never filled, so the contractor had to cut out years of accumulated dust and dirt from between layers of sealer. Workers then filled the joints with polyurea to create a seamless, sanitary floor. They continued to work their way up through the grinding stage.
The most difficult part of the project, however, occurred halfway through the honing stage. After using a 200-grit metal-resin hybrid diamond tool, crew members divided the slab into multiple sections so they could reapply four different colors using acetone dye. However, they couldn’t tape off the sections because the tape could potentially bleed or damage the already dyed areas.
So they started dying with the lightest color: gold. One man sprayed while the other three held paint shields to ensure there was no overspray onto the adjoining sections. Next they applied burnt sienna, then chocolate brown, and finally midnight black, constantly wiping their shields to prevent dripping. The crew then cleaned the dye residue off the surface with an autoscrubber, working small sections so that the water wouldn’t dry and stain the floor before getting picked up. Next, they applied densifier until rejection.
Ardor finished the honing stage, and polished the floor up to 1800 grit. To protect the floor from the acidic lunchroom foods, the contractor applied two coats of guard to the floor. Each coat was applied at a rate of 3500 to 4500 square feet per gallon. The crew finished by running a burnisher—two slow passes with an 8500-grit, diamond-impregnated pad.