It looks like gleaming obsidian, in colors of caramel, pine green, walnut and charcoal.
It looks liquid.
It looks gem-like.
It doesn’t look like concrete.
It’s concrete -- hardened, densified, color-dyed and polished to a shine that’s -- well -- divine.
Design architect Michael Brush, Plunkett Raysich Architects, Milwaukee and Madison, said he chose the concrete floors for their honesty, and for the informal, youthful atmosphere they help create.
“Concrete is a perfectly good, solid surface, worthy to be shown,” Mr. Brush said. “The floors have many of the qualities of terrazzo, though without the aggregate, and at less cost.
“The depth and consistency of the color is exciting,” he added. “And I’m always impressed with the level of finish you can achieve on concrete.”
Though Mr. Brush chose the concrete floors for their aesthetics -- they make a statement about the Blackhawk congregation, he said -- “green” considerations were still a factor, if not the main one.
“I always like to avoid superfluous materials when possible,” he said. “In this case we didn’t need extra factory-made coverings or the expense and effort of having them transported to the site.”
The church floors feature curving arcs of reflective concrete color in the building’s two sanctuaries, the major circulation routes, the welcome center, and the youth and music area.
Crews from the concrete artisan firm Specialized Inc, Waterloo, Wis.; and D & B Industrial Floor Coatings Inc., Menomonee Falls, Wis., worked together to turn the gray concrete pour into the sleek, beautiful floors.
The two companies do a lot of work together, says Brad Van Dam, president of D & B.
“D&B Industrial Floor Coatings specializes in high-production, cost-effective polishing procedures and methods, and has honed their craft on large retail and industrial facilities through the 55 years they have been in business,” Mr. Van Dam said.
At Blackhawk Church the marriage of Specialized Inc.’s artistic designs and D & B ‘s methods and procedures produced beautiful work at a pace most people could hardly believe, he said
“We’ve been working together for six or seven years now,” added Shawn Wardall, Specialized Inc.
Their work at Blackhawk Church began as the concrete floors were poured to Mr. Wardall’s specifications.
Pours were done in phases of 2,000 - 4,000 square-feet each and machine-troweled. Even as concrete was being poured in one part of the church, D & B and Specialized Inc. technicians worked the already-cured floors in other areas.
They began by cleaning the new floors with several types of cleaner/degreasers, including PROSOCO’s Enviro Klean® 2010 All Surface Cleaner, and a floor-scrubbing machine.
Most of the floors got an initial grind with a 50-grit resin diamond.
“We had several areas where they accidentally hand-troweled instead of machine-troweling like we wanted,” Mr. Wardall said. “so we started those with a 70-grit metal bond resin to compensate for the rougher finish.”
After the initial grind, the workers took the floors in stages up to a 400-resin polish.
Mr. Wardall used lengths of half-inch sprinkler pipe and painter’s tape to create the architect’s graceful, sweeping arc designs on the newly polished floors. Once the tape was down, he removed the pipe and saw cut 1/16th to 1/8th of an inch deep along the tape edges.
The cuts made for crisp, precise separations of the differently colored concrete areas as the dyes were spray-applied, Mr. Wardall’s next step.
After dyeing, the techs washed the floors again to remove excess dye residues, and let the floors dry. Then they applied Consolideck® LS™ (lithium silicate) hardener/densifier, provided by Glenrock Company, Menomonee Falls.
LS™ increases density, hardness and durability by reacting with the concrete to precipitate insoluble calcium silicate hydrate in the microscopic concrete pores. It’s the same tough material that makes all concrete hard to begin with as its Portland cement cures -- only more of it.
The extra calcium silicate hydrate gives the “wear zone” -- the top 1/16th to 1/8th of an inch -- a significant and measureable increase in hardness, denseness and durability -- desirable qualities for any concrete floor.
Crewmembers applied the LS™ with pump-up sprayers, and spread it with micro-fiber applicators. The floors got second coats after the first coats dried in about an hour, Mr. Wardall said.
“I’ve used other products for hardening and densifying,” Mr. Wardall said, “but there was always too much white residue left. Between the ease of application and the finished product, the lithium’s better.”
The techs took the newly hardened, densified floors up to an 800-grit polish and applied three coats of Consolideck® LSGuard™, with pump-up sprayers and micro-fiber applicators.
LSGuard™ produces a protective film that gives the hardened colored concrete a further measure of protection from spills, stains, abrasion, traffic and construction activity. Its lithium silicate content also contributes to increased hardening and densification.
The crews burnished in the LSGuard™, giving the floors a final extra measure of luster.
“That’s what intrigued me the most,” Mr. Wardall said. “The brilliance you can get with LSGuard™ -- it pulls the colors out like a solvent finish, except it’s not a solvent and you don’t have the VOC issues.
Although Mr. Brush, the designer, originally specified another product for hardening and densifying, he said he was “more than happy to make the change,” once the Consolideck® products were demonstrated.
“That was absolutely the right choice,” Mr. Wardall said.
“The clients love the floor. They’re calling it ‘awesome,’ and using all those adjectives you like to hear -- even those who were skeptical of concrete.
“They’ve discovered what many of us have known about all along – the true beauty you can create with concrete.”
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For more info, contact Gary Henry at 785-830-7343 or e-mail [email protected]
