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.
But 63,000 square feet of the total 200,000-plus
square feet of floor space in the new Blackhawk Church, which opened
Nov. 4 in Madison, Wis., is just that -- 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
“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
“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 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
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 at the end of
May, as the concrete floors were poured to Mr. Wardall’s
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
“We had several areas where they accidentally
handtroweled 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 shine.
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
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.
“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 shine and applied three coats of
Consolideck® LS Guard, with pump-up sprayers and micro-fiber
LS Guard produces a protective film that gives the hardened colored concrete a further measure of
protection from spills, stains, abrasion, traffic and
Its lithium silicate content also contributes to
increased hardening and densification.
The crews burnished in the LS Guard, 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 LS Guard - 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
LS products were demonstrated.
“That was absolutely the right choice,” Mr. Wardall
“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.”