The University of California, Riverside (UCR) Office of Research and Economic Development runs a vivarium, a research facility with highly controlled environments for the care and maintenance of experimental animals. In 2019, UCR completed the construction of a Multidisciplinary Research Building to house the vivarium along with four stories of collaborative space.
In May 2018, the vivarium’s concrete floor had already been poured under the direction of general contractor Hensel Phelps. The coating specifications for the 20,554-square-foot (1,909.5 m2) vivarium called for a seamless, non-slip surface that would be resistant to chemicals, organic and inorganic materials, elevated pressures, and other factors. Proper drainage and rounded corners were necessary to sanitize the area effectively and easily and to keep mold from developing.
However, by this time, the original specifications were a bit out of date. So Hensel Phelps invited Oakridge Industries Inc., an industrial coatings firm specializing in pharmaceutical and research facility construction projects, to bid on it. Based in nearby Pomona, Calif., Oakridge’s regional sales manager, Eric De Rose, reached out to Ray Gutoski at Arizona Polymer Flooring (APF), and they teamed up to win the job.
Together, Oakridge Industries and APF designed a system that fit both the budget and the needs of the client. “We have extensive experience in biotechnology projects,” explained De Rose, “and we knew just the system for the job.” But first, some issues had to be dealt with.
In the Basement
Oakridge Industries, which employs approximately 40 people, began with moisture testing. Gutoski explained, “When you get into the basements of these facilities, especially in new constructions, there is a high probability that you’re going to have some sort of moisture issue still. We kind of anticipated that.”
“We used a calcium chloride test,” said De Rose, referring to ASTM F1869, "Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride." These tests are put down at three per 1,000 square feet (92.9 m2) and then one every additional 1,000 square feet. More than 20 tests were put down in the vivarium space.
And what did the results show? “I’m going to say we were around 5 pounds [2.3 kg],” said De Rose, speaking about the moisture content per test area. “The moisture vapor drive exceeded the manufacturer’s limit of 3 pounds [1.4 kg]. So we ended up having to install the APF VaporSolve Ultra System.”
The next step was to create a mockup of the full coatings system. A room of approximately 100 square feet (9.3 m2), plus cove bases, was chosen. “The mockup was done absolutely to perfection,” commented Gutoski.
De Rose was at the jobsite regularly during this initial process “because the mockup actually had to be documented,” he said. “I was there every day taking photographs, submitting the daily tasks and the process of the mockup. Then once the project got rolling, I would check in two to three times a week with my foreman and one of our other project managers, just to ensure that everything was going perfect.”
Prep and Moisture Mitigation
Another significant issue with some of the flooring was the slope. In one of the rooms, the concrete was depressed and had to be filled and sloped to the drains.
“Instead of having them go back and tear it out,” recalled Gutoski, “we just sloped it with epoxy mortar before we were able to put the system in there.” The depressed concrete was raised and sloped with APF Epoxy 400, a low-viscosity, 100-percent solids resin system.
Next on the agenda was surface preparation. The concrete was bead blasted to the International Concrete Repair Institute’s Concrete Surface Profile (CSP) 5 using Blastrac 1-10D and 1-20D machines and heavy steel shot #330 from Metaltec Steel Abrasive Co. All edges were diamond ground using DEWALT and Metabo grinders, all drains and terminations keyed in, and all cracks routed open using Makita saws.
During blasting, standard personal protective equipment (PPE) was worn. De Rose said, “Everyone was wearing work boots, work gloves, jeans or work pants, long sleeves, safety vests, eye protection, face shields when you’re doing all that blasting, ear protection, 3M respirators. We always have full PPE. Our guys are always wearing it — you have to nowadays. You can’t just walk in there with your hat on backwards.”
Oakridge had an average of eight to 10 workers on the project. De Rose explained the workflow among the crew: “Usually with the blasting you have two guys — one guy running the equipment, one guy doing the hose, moving the cords. One other guy follows behind with a magnet. It’s a roll-behind magnet, to pick up all the shot that’s on the ground so people don’t slip. Then you’ve got three or four guys doing all the edge grinding, and then you’ve got a guy crack chasing, opening cracks, and keying in. Then there’s usually a guy going around — you’ve got your negative air — all your negative air machines are hooked up, your HEPA [high-efficiency particulate air] vacs. With the new OSHA and silica regulations, everything is HEPA vac’d.” The HEPA vacuum was a walk-behind model from Ermator, and the negative air machine was a Force Air 2000 EC from Advanced Containment Systems, Inc. (ACSI).
After surface prep, the crew applied APF’s three-step VaporSolve Ultra System for moisture mitigation: a water-borne epoxy primer that deeply penetrates and adheres to silicate-contaminated concrete; a joint filler where necessary; and a finish coat of VaporSolve 100, which is specially designed to greatly reduce the possibility of concrete outgassing.
The VaporSolve primer and finish coats were applied by squeegee and backroller at an average of 8 mils (203.2 microns) per coat. Drying time for each coat was overnight, between eight and 12 hours.
The crew used 18- and 24-inch (45.7 and 61.0 cm) squeegees and 9- and 18-inch (22.9 and 45.7 cm) rollers. “Sometimes we were also using the notched squeegees because that gives you the proper millage,” added De Rose.
A 6-inch (15.2 cm) integral cove base — stretching 4,555 linear feet (1,388.4 m) in all — was also installed in the vivarium using APF’s Epoxy 600, a low-viscosity, 100 percent solids, high-performance resin system. From there, the specified flooring system could be installed.
The particular APF ArmorRez system on this project — a unique system applied at the owner’s request — was a slurry double-broadcast system with a nominal 3/16 inch (4.8 mm) thickness. “This is not typical,” explained Gutoski.
Two colors of Estes brand quartz were broadcast into a slurry and topped by one lock coat of a clear epoxy followed by APF Polyurethane 100. The slurry coat was hand troweled, with some use of brushes, but all the other coats were squeegeed and backrolled. Both De Rose and Gutoski said there was a lot of detail work that had to be done by hand. “Lots of rooms and lots of corridors. You’ve got a lot of inside corners,” said De Rose.
The final topcoat, Polyurethane 100, is a two-component, high-solids, low-volatile organic compound aliphatic sealer. It is designed to provide high abrasion and scratch resistance, easy soil release, and excellent resistance to a broad range of chemicals.
In all, the project took 12 weeks, and it’s been a great success. The decision makers and facility managers for the UCR research facility have been “extremely pleased with the look and performance of the flooring since completion of the job,” said De Rose. And without any shyness, Gutoski added, “It turned out beautifully.”