Building Teams and their clients tend to think of a decorative concrete contractor as just another trade to be fit into the construction schedule, preferably at the lowest possible cost. But installing decorative concrete can be a delicate process, making planning for the construction crucially important.
At one time, decorative concrete came in only a few finishes—colored concrete, acid-etch stained, and stamped patterns. Today, there’s an almost infinite number of finishes available for horizontal and vertical surfaces—stamped, textured, integral and dust-on, colored, acid etch, dye (water and solvent), stampable overlays, self-level overlays, micro-toppings, stencil, engraved, form liners, diamond polished, sandblast, exposed aggregate, and coatings (epoxy, urethane, and acrylic). Finishes can also be combined with other finishes.
The possibilities are limited only by creativity of the designer and concrete contractor, yet it’s that very creativity that makes using decorative concrete so attractive. The problem is that concrete is very sensitive to a wide range of variables that can negatively impact the outcome.
ALSO SEE: 8 Innovations That Will Rock Your Next Concrete Project
To learn more about how to control these variables and thereby make decorative concrete a successful component of your next project, we consulted Mike Miller, Managing Principal of The concretist, Benicia, Calif. (www.theconcretist.com), one of the oldest decorative concrete contractors in the business. The term “concretist” refers to “one who practices concrete poetry,” and Miller himself is widely known for the almost poetic nature of his work.
1. Correctly assess—and manage—client expectations.
Miller says projects should start with the owner providing a full description, preferably in writing, of what the finished product should look like. Then the contractor can respond with what’s physically, aesthetically, and financially feasible. Sometimes owners have unreasonable expectations; early discussion can help manage those expectations.
What Building Teams should do when specifying decorative concrete:
1. Correctly assess—and manage—client expectations.
2. Choose the right decorative concrete contractor.
3. Carefully schedule the work of other trades to avoid undue damage to the concrete.
4. Provide the right protection for the finished work.
5. Negotiate an agreement with the client/owner on post-occupancy maintenance.
Decorative concrete usually isn’t structural in nature, although specifications are often written as if they were. For instance, a specification might require concrete with high compressive, tensile, or flexural strengths cured in a prescriptive manner. Or a specification might require “green concrete” with a certain percentage of the portland cement substituted with fly ash, slag cement, or other pozzolanic materials.
Miller’s advice: Focus first on the requirements for a good decorative installation; otherwise the work might meet all the structural requirements but be rejected for aesthetic reasons. For example, applying the usual curing specification for plain concrete to decorative work could have disastrous results, to the point of permanently damaging the look of decorative work. He urges Building Teams to use pre-job conferences to focus on the “dryness” of concrete or the slab relative humidity needed to start finish work rather than how to retain more moisture for curing purposes.
2. Choose the right decorative concrete contractor.
There can be significant variations in the creative abilities of decorative concrete contractors, says Miller. If you want highly creative work you must find a contractor who can perform at that level and who also possesses good craft skills. Contractors tend to specialize in certain types of decorative concrete these days, so you’ll have to narrow your search to get the right one for your job.
A word of caution: Miller says some decorative concrete contractors don’t place-and-finish concrete and wouldn’t know how to do it if asked, so you might have to hire a place-and-finish concrete contractor in addition to a decorative specialist.
3. Carefully schedule the work of other trades to avoid undue damage to the concrete.
Unfortunately, decorative concrete is highly susceptible to damage by other trades, more so than tile or other finished floor surfaces. Damage to concrete slabs can occur before decorative work begins or afterwards. Plumbers have been known to spill cutting oil, hot solder, and plastic pipe glue on slabs. Carpenters seem to think that any flat surface was put there so that they could pile stacks of lumber on it. Even trade workers’ footprints on floors that are hard but still considered “green” can become visible when acid-stain finishes are applied. Shoe soles also contain oils that may act as a resist.
To avoid conflicts with other trades, Miller recommends scheduling this work starting on a Friday afternoon and proceeding through a weekend. With no one on the job site to cause problems or delays, he says that’s the best chance for success.
4. Provide the right protection for the finished work.
The common belief about concrete is that it gets hard, becomes even stronger over time, and that’s pretty much it—no need to worry further. But that is not the case. Concrete remains vulnerable because its chemistry continues to change as it ages, and water on slab surfaces can bring about other physical and chemical changes. That’s why it’s so important to include a plan for protecting the finished work in pre-job meeting discussions.
Miller says covering material must allow moisture vapor from concrete to pass through while not allowing products that can stain to reach the surface of the concrete. The responsibility for the finished work is not a trivial matter. Since the concrete contractor cannot be expected to stay on the job until the concrete has fully cured, the responsibility for protecting the decorative work falls to the general contractor. However, that does not absolve the decorative contractor of all responsibility. The subcontractor should suggest the best protective products to use and perhaps even install them the first time.
5. Negotiate an agreement with the client/owner on post-occupancy maintenance.
A long-term maintenance plan should be part of the discussion your Building Team has with the client and facilities staff before construction begins. There are several ways to seal decorative work; each sealer provides a unique appearance. If an owner wants a glossy “wet look,” an epoxy, polyaspartic urethane, or acrylic finish is a good choice. These finishes must be renewed per the manufacturer’s recommendation. The accepted standard is that pedestrians should walk on the sealer, not on the concrete.
ALSO SEE: The world’s first building made from carbon-fiber reinforced concrete starts construction in Germany
If the owner wants a natural concrete look without a glossy appearance, there are penetrating sealers on the market that restrict pore openings so that dirt and other staining materials will not penetrate the surface.
Diamond-polished floors present additional maintenance problems. Owners typically want these floors to have a high-gloss shine, but dirt and fine grit become abrasive under foot traffic, dulling the surface gloss over time. Some big-box retail companies have maintenance programs to remove dirt and grit on a frequent schedule. In grocery stores food spillage must also be removed and cleaned as it occurs.
The inspirational aspect of decorative concrete
There are good reasons for the growing popularity of decorative concrete. It’s in our nature as humans to surround ourselves with creative expression and color; we like to be emotionally pleased by our environment.
Today, there are many more options for Building Teams to provide that kind of satisfaction through the use of decorative concrete. That’s why it’s important for Building Teams to work with their decorative concrete contractors to meet these heightened client expectations and ensure a long and useful life for these beautiful, inspiring surfaces. +
--
Joe Navsik, a freelance writer in the Chicago area, is a former editor at Concrete Construction magazine.
Related Stories
| Sep 6, 2013
Public Architecture's Day Labor Station: Just the type of 'great idea' we're looking for in the $5,000 Vision U40 competition
Thinking about competing in BD+C's Vision U40 program at next month's U40 Leadership Summit? Here's a good example of the kind of "great idea" we're looking for.
| Sep 6, 2013
U40 Summit featured speaker: Arthur Gensler on how to build a world-class AEC practice
Gensler, founder of the world’s largest architecture firm, will talk about the role of the architect in society, the impact of great design, and the practicalities of starting and running a practice, and will offer advice for today’s young design and construction professionals.
| Sep 6, 2013
Nonresidential Construction Index holds steady in Q3
FMI's 2013 Third Quarter Nonresidential Construction Index report shows a NRCI score of 60.3, a .2-point improvement over Q2.
| Sep 5, 2013
Do you have the next big breakthrough for the AEC industry?
Next month's Under 40 Leadership Summit in San Francisco is your place to shine. Our third annual networking and leadership event for young AEC professionals will feature an XPrize-type competition, called Vision U40, that will reward attendees who develop the most innovative solutions to today's pressing issues.
| Sep 4, 2013
Identifying your leadership gaps
U.S. businesses spend more than $170 billion annually on leadership-based curriculum, according to the American Society of Training and Development. Is all that training producing better leaders or just more people who hold positions of leadership?
| Sep 4, 2013
Augmented reality: 12 applications for design and construction professionals
Building Design+Construction reached out to AEC professionals who have studied and applied augmented reality and asked them to pinpoint applications that are ripe for the technology. Here’s what they had to offer.
| Sep 4, 2013
Augmented reality goes mainstream: 12 applications for design and construction firms
Thanks to inexpensive mobile devices and increasingly advanced software apps, Building Teams are finally able to bring their BIM models to life on the job site.
| Sep 4, 2013
K-12 school design that pays off for students
More and more educators are being influenced by the Reggio Emilia approach to pedagogy, with its mantra of “environment as the third teacher”—an approach that gives Building Teams a responsibility to pay even closer attention to the special needs of today’s schools.
| Sep 4, 2013
Video: Autodesk Fellow Tom Wujec on why you should join the Vision U40 competition
Tom Wujec, lead facilitator of BD+C's 3rd Annual Under 40 Leadership Summit, October 9-11 in San Francisco, explains the Vision U40 competition, which will launch at the event. U40 Summit participants will collaborate in small teams to develop innovative solutions to today's pressing social, economic, technical and cultural problems related to the built environment. They will complete for $5,000 in prizes.
| Sep 4, 2013
Smart building technology: Talking results at the BUILDINGChicago/ Greening the Heartland show
Recent advancements in technology are allowing owners to connect with facilities as never before, leveraging existing automation systems to achieve cost-effective energy improvements. This BUILDINGChicago presentation will feature Procter & Gamble’s smart building management program.