Here's more about the 2010 Concrete Restoration Contest winner in the Interior category - in the artisan's own words.
First Place, Interior: Premier Veneers, Frankfort, Ill.
Project: Soccer Madness, Buffalo Grove, Ill.
by Jeff Donius
This flooring project is a new sporting goods store in Buffalo Grove, Ill., called Soccer Madness. It is a 2,650-square-foot existing concrete floor in a retail shopping plaza under renovation and restoration for the new owners to use the storefront. The maintenance company employed by the plaza owners was not properly equipped to do the specialized work, so they allowed the new tenants and owners of the store to hire a concrete flooring specialist to do this work.
The owners called my company, Premier Veneers, of Frankfort, Ill., for an on-site consultation to determine what work would be involved in the renovation and restoration. I performed the consultation, including an evaluation of the adhesive on the floor, the depth, and the best means of removal. The owners knew they wanted the look of acid stain, but they didn't know how to achieve it, realizing the state of the concrete floor could be compromised during the adhesive removal process.
During the consultation, I ground off some adhesive with a handheld grinder. I found yellow, water-based carpet glue on the surface, with black, solvent-based, cutback adhesive underneath. I determined the most efficient method of removing the adhesive to be a 220-volt walk-behind grinder with polycrystalline diamond cutters (PCDs) and then 20-grit L-segmented diamond discs for the interior of the floor, followed by a handheld grinder around the walls with a 24-grit ZEC sanding disc and then a 40-grit segmented, diamond turbo cup.
It also became apparent that the floor would require extensive concrete repair. The repairs would be best made by using an epoxy mortar and fiber-reinforced grout, followed by a cement overlay that would not only hide the repairs, but cover the exposed aggregate from grinding, and provide a new surface for staining. After the consultation, I told the owners I would prepare an overlay sample board so they could envision the final appearance of the floor. The owners approved the overlay board and hired me for the project.
I spent three days grinding the adhesive off the floor. This meant two days with a 230-volt, single phase, walk-behind Terrco concrete floor grinder, combined with a Blastrac dust containment system, to remove the adhesive on the interior of the floor, and one day with a Porter-Cable Flex handheld grinder to remove the adhesive along the walls, and to remove remaining, recessed areas of hard-troweled concrete that couldn't be reached by the walk-behind grinder. These hard-troweled areas were too dense to allow for proper adhesion of the overlay.
After grinding the concrete, I filled three isolation joints on the floor with a semirigid epoxy mortar from Sika, then applied a fiber/rubber flexible cement membrane from Mapei over the surface to absorb and deflect any settlement movement from below and to prevent the overlay from cracking. Later, the styrene butadiene adhesive in the cement overlay would help to absorb and deflect any additional subsurface movement.
I also ground out several nails, screws, bolts, and pieces of metal attached to the floor with a Metabo 4-inch angle grinder and carbide cutoff wheel. I filled in the remaining recessed areas with another epoxy mortar from Sika and a fast-setting cement from CTS Cement. Finally, I coated the corners of the project space, where the adhesive was difficult to remove, with an epoxy saturated with silica sand to provide further traction for the overlay. I also used a water-tolerant epoxy to coat areas of the floor near the entrances of the storefront that wouldn't dry due to snow-related moisture.
Once the concrete repairs were done, I acid-etched and neutralized the floor to remove leftover dust from grinding and to dampen the substrate so that the overlay could dry slowly and draw additional moisture for hydration. The etching process helps to ensure proper bonding and long-term durability of an overlay. Once the acid etching was done, I used an electronic pH meter from IQ Scientific Instruments to test the pH. The resulting values were approximately 7.2 on average.
I then applied two skim coats of a natural colored cement overlay from Decosup. Each of these two layers was applied at a depth of approximately 3/32 inch. These two layers were intended to provide durability and hardness to the overlay system. Once these layers dried, I applied a white microtopping to the system at a depth of 1/16 inch, to provide a high-content cement surface for the staining portion of the project. In all, the entire overlay system turned out to be approximately ¼ inch thick.
Next, I sanded the microtopping with a rotary floor machine from Oreck, using 100-grit silicon carbide sanding screens from Norton Abrasives. This revealed part of the natural colored overlays and created a two-tone surface that would intensify the marbling effect of the stain. I also recut the control joints, and did additional saw-cutting to create an overall rectangular tile pattern that would incorporate the control joints into the overall design. The hardest part of the whole overlay process was using fiberglass plastic dividers (8 by 2) in all of the saw cuts so that they would not be completely filled in with cement.
The owners wanted two colors on the floor: gold and Jacobean brown. I accomplished this by using two different colors of stain from a single manufacturer: an amber and walnut from EZChem USA. I started with a base coat of amber diluted 2 to 1 with water, a second coat of walnut three hours later at 8 to 1, and then four more coats of amber and walnut three hours apart at varying mixes and dilutions. I used pump-up sprayers from RL Flomaster, changing nozzles and tips several times in the process. Overall, the project required only three gallons of stain. After the stained dried overnight, I rinsed and neutralized the floor with a warm solution of ammonia and water.
This time when I tested the pH, the values were approximately the same: 7.2. This accuracy was important because of the type of sealer I used, a water-based epoxy from Decosup. Water-based epoxies will not properly cure or adhere at pHs above 7.5. I applied three coats of this water-based epoxy with an 18-inch roller cage and 3/8-inch roller covers from Midwest Rake, allowing for dry times of 12 to 13 hours in between. I was forced to use the water-based epoxy because of the confined breathing space of the project, the restaurant next door, and the desired sheen and gloss of the floor.
I applied the epoxy in thin, even, uniform applications. Water-based sealers go down milky white in appearance and do not clear up, if applied more than about 2 mm in thickness. But here was still a problem with blushing by the front and rear entrances of the store because of the cold winter temperatures, moisture from condensation, and icy near the floor. I worked around these problems by using fans to dry these floor areas and then dry the water in the sealer quickly.
Finally, I applied four coats of a high-solids floor polish from Spartan Chemical, called On an' On, to bring a higher gloss and optical clarity to the stained concrete and to ensure that the sealer on the floor would not be scratched or damaged by customers, workers, or delivery personnel. Using this polish from Spartan, the new floor of this store could also be easily cleaned and maintained by the owners so as to last indefinitely.
The overall renovation and restoration of the floor took 18 days and went completely according to plan. This once structurally deficient concrete floor, laden with adhesive, is now the beautiful foundation and backdrop for this successful sporting goods store in Buffalo Grove, Ill. My company, Premier Veneers, performed every element of the renovation and restoration: evaluation and assessment (3 days), cleaning and renovation (3 days), concrete repairs (2 days), cement resurfacing (5 days), and stain and sealing (5 days).
In this last picture, you can see how well decorated and organized the entire store is. This store is a good example of how the ancient Eastern art of feng shui can be incorporated into the architecture and construction of American buildings to bring harmony and peace to a business. Feng shui has grown greatly in popularity in the Western world over the last 33 years, and its principles are now mainstream in American architectural and design, and the world of corporate consulting.
