CASE STUDY: APPLE INC., STEVENS CREEK BUILDING 8

Photos courtesy of CTS Cement Manufacturing Corp.

Location: Cupertino, CA
General Contractor: Novo Construction
Contractors: Floor Seal Technologies and Clean Cut Concrete, Inc.
Architect: Studios Architect
Applications: TRU^® Self Leveling Polished Concrete Overlayment System

The existing underlayment material on this project was defective, which had to be removed prior to starting with a polished concrete system. Once the defective material was removed from the existing substrate, the substrate was profiled to a minimum ICRI surface profile of 3. Then the existing cracks were detailed and filled with a fast setting low viscosity repair material and broadcasted with a silica sand.

With the repairs complete and the subsurface prepared, then the overlayment system could be installed. First, epoxy primer was placed at 12 mils and broadcasted with a 30 mesh silica sand to refusal. After 12 hours of the epoxy curing, the excess sand was removed. Next, the self-leveling underlayment material was installed to a depth of approximately 1.5 inches, roughly ½ inch from the finished floor elevation. After 12 hours of curing, this layer was profiled with a shot blaster and ready to receive a top layer of epoxy primer which was again applied with sand, cured for 12 hours and the excess sand removed.

The floor was now ready to receive ½ -inch-thick polished concrete overlayment floor system. With this particular project, the finish included a custom blend of aggregates with a liquid integral colorant. The materials were mixed in 5 bag Hippo batch mixers to control consistency. Once the overlayment was placed over the primed surface, a gauge rake was used to place the material to the desired thickness, followed by a spike roller used as the finishing tool. The spike roller removes the tool marks from the gauge rake and assists in leveling the finish surface. It also helps in removing any trapped air sometimes caused in the mixing process.

The overlayment reached a minimum of 5,000 psi in 24 hours and then received its first grinding step of a 60 grit metal diamond. During the second grinding step using 120 grit metal, a grouting system was incorporated in the grinder equipment that mixed with fine concrete dust and filled the minor imperfections of the surface. The overlayment was then polished to 800 grit prior to the application of a final coating. Due to the overlayment’s high density and low polymer load, polishing produced both high gloss and distinctness-of-image readings (DOI).

Photos courtesy of CTS Cement Manufacturing Corp.

CASE STUDY: NORDSTROM RACK

Photos courtesy of CTS Cement Manufacturing Corp.

Location: Manhasset, New York
General Contractor: All Stone Restoration
Applications: Self Leveling Polished Concrete Overlayment System

When renovating the Nordstrom Rack retail store in Manhasset, NY, the contractor, All Stone Restoration, discovered that many steps were involved. The existing multi-layer floor had deteriorated and needed to be ripped out so a new floor could be installed and leveled, all within a rather tight working space. The contractor knew that cement products would be needed that would quickly set and create a decorative concrete finish.

The first step was to rip out the existing floor, revealing a remaining surface that was uneven. To rectify the situation, an advanced hydraulic cement based self-leveling underlayment (SLU) was selected that can be used both indoors as well as outdoors. This SLU covered and cured in 6 to 16 hours at 70°F (21°C). Multiple layers of primer were then used. A rapid set acrylic primer improved the adhesion of the SLU to the underlying concrete. To produce an even top surface, a two-component, low-VOC, moisture- and alkali-insensitive epoxy primer was selected as it is recommended for most wear topping and decorative system installations. Additionally, the use of the SLU and the primers before placing the final overlayment layer allowed the owners to save money on the job, compared to exclusively using overlayment material.

For the next step, a self-leveling overlayment layer was colored to meet the specified lighter grey, per the owner’s preference, and installed on top of the primers. The final floor was then polished. “The overlayment and self-leveling products are the strongest to work with, as far as minimal cracking, nice appearance, and better results in the long run,” said Clint Comparetto, president, All Stone Restoration. “The manufacturer's flooring experts are also known for their excellent support.” In the end, the contractor successfully met all of Nordstrom Rack’s tight specifications through the use of the proper cement based products.

CASE STUDY: UNIVERSITY OF BRITISH COLUMBIA STUDENT UNION BUILDING

Photos courtesy of CTS Cement Manufacturing Corp.

Location: Vancouver, British Columbia
Client: UBC Properties Trust
Size: 5,850 square meters/63,000 square feet
Architects: Dialog Design
Collaborators: B+H Associated Architects
Applications: Self Leveling Polished Concrete Overlayment System
LEED Registered: Platinum

The members of the Properties Trust at the University of British Columbia in Vancouver decided it was time to build a new student union building (SUB) for their vibrant campus. The selected location placed the new SUB between an existing 40-year-old building to the north and University Boulevard to the south, framing the east face of a new university square. Being a student union building, the structure naturally includes many walkways and restaurants. In fact, the SUB contains multiple levels with a total of 63,000 square feet of new concrete overlayment flooring in the 225,000-square-foot building. Further, green building design was a priority resulting in a project that has been certified at the LEED Platinum level.

The high foot traffic areas in walkways and restaurant areas called for flooring using integrally colored light concrete surfaces with aggregate and a polished surface. To produce an even surface, a two-component, low-VOC, moisture- and alkali-insensitive epoxy primer was first placed over the newly poured and prepared concrete floor layer. Shortly after 12 hours of curing, the floor was ready for the overlayment system. As an advanced, professional grade, hydraulic cement-based, self-leveling topping, the overlayment provides a high-quality and durable finish. Through grinding and polishing, 24 hours after the overlayment was placed, the aggregate was exposed and the desired finished appearance was attained. With this particular project the system included a custom blend of aggregates with a liquid integral colorant. After being placed over the primed surface, a gauge rake was used to place the material to the desired thickness and a spike roller was used as the finishing tool. Then the surface was ground and polished, ready for the throngs of students who use the building daily.