A 5-inch grinder may weigh less than 10 pounds, but imagine using it on a wall day after day, week after week, while standing on a ladder. Or kneeling. Or crouching. Or lying on your side. Physical discomfort is one reason most polishing contractors prefer horizontal over vertical jobs. Not so for Desco Coatings of Alberta Ltd., however.
The 2014 Concrete Surfaces Polished Concrete Awards winner began as a purveyor of Vitroglaze wall coatings before introducing polished concrete to western Canada. Today, 60 years after brothers Nestor and Orest Samycia founded Desco, crews have worked out many kinks inherent to the growing vertical-surface market.Even so, the lobby of Edmonton, Alberta’s new recreational center was a testament to tenacity.
A joint development of the City of Edmonton and Edmonton Eskimos Football Club, the 220,000-square-foot Commonwealth Community Recreation Center adds a swimming pool, gym, and field house to the Canadian Football League team’s stadium.
Opened in 2012, the $96 million facility earned LEED Silver certification in part by incorporating a U.S. Green Building Council-approved floor finish: polished concrete. Desco polished almost 24,000 square feet of benches, columns, staircase, walkways, and walls in the lobby to a salt-and-pepper finish, defined by the Concrete Polishing Association of America as 1/16-inch deep with little or no medium aggregate exposure at random locations.
Desco further contributed to project sustainability goals by using environmentally friendly products and practices. These include using VOC-compliant products made by Convergent Concrete Technologies LLC of Orem, Utah: Pentra Sil (NL) to densify, and Pentra Finish HG as a hardener and protective clear coat. The products’ silicon-based nano-lithium molecules extend wear resistance by penetrating into the concrete and reacting with free calcium ions to form an insoluble calcium silica hydrate.
Proper body positioning
After testing different materials and techniques onsite, the crew combined a proprietary structural urethane grout, various sand mixtures, and leftover concrete dust from grinding into a material that matched the color of the surrounding surface and could be trowelled vertically. The grout was modified depending on the size of the bugholes: more sand and small aggregates for larger holes, finer sand for smaller holes.
After the grout cured, crews polished the surface by hand with 5-inch variable-speed grinders. They repeated the process until all of the bugholes were filled, which often required four or five lifts. Very little, if any, work was done from a ladder and scaffolding. Instead, workers spent most of the time lying on their sides, kneeling, crouching, or working at standing height.
“Holding a grinder while applying the correct amount of pressure and keeping the diamonds flat so as to not scratch the surface is exhausting and requires a great deal of mental concentration,” says president Daryl Samycia, Nestor’s son. “This was further complicated by having irregular surfaces, such as the white benches, where the operator had to ensure that the grinding surface remained parallel to the concrete surface at all times.
“The project wouldn’t have succeeded if it weren’t for our crew working with sheer dedication as a team.”
He takes pride in the company’s training and safety, and, given employee tenure, such perks must make occasional physical discomfort worth it. On average, Desco’s 45 employees have worked for the company for more than 10 years.
Visit www.descoalberta.com for more.