Concrete's durability, strength and low maintenance have long been hallmarks of its appeal. And now that the market for decorative concrete is exploding, customers are willingly paying premiums for colorful, eye-catching driveways, walkways, pool decks, patios and more.
While maintenance of concrete is minimal — that's the beauty of it — decorative concrete does require regular cleaning and resealing to extend its life and eye appeal for years into the future.
Unfortunately, though, regular maintenance programs are often overlooked by contractors and customers alike.
Ronald Borum, executive vice president of Crossfield Products Corp. and manager of the Miracote Division, says the industry as a whole has failed to do a good job of teaching customers how to maintain the color integrity, brightness and brilliance of decorative concrete. Concrete is indeed durable, but the color itself may have less resilience.
“I think a lot of people in our industry — designers, architects, landscape/hardscape persons, contractors — sell that pristine look without looking down the road, and the customer ends up buying something that two years or more down the road they're very dissatisfied with because they don't understand how to keep it pristine and close to that original look.”
Education about the importance of regular maintenance can result in happier customers and more business for contractors.
Cleaning is the cornerstone of maintenance
A thorough cleaning is the foundation of proper maintenance. It's critical, because concrete is so porous. “Concrete is not a piece of Formica, it's more like a sponge,” says Steven W. Hicks, president and CEO of ConcreteScience International Inc.
His Minnesota-based company handles the dirtiest of industrial jobs, where simple pressure washing just isn't enough. ConcreteScience's extraction cleaning services involve pretreating the surface with specially formulated chemicals. The cleaning equipment uses heat and pressure to remove the contaminants and vacuums away most of the water, leaving the surface nearly dry. Most sealants can be applied immediately.
“When you extraction clean, it's incredible what happens,” Hicks says. “What you've done, other than make it look pretty, is you've extracted the dirt out of the pores of the concrete.”
Many times, Hicks says, clients are surprised to find colored concrete beneath the dirt and grime. “Sometimes it's just so filthy, you have no idea what you're going to find when you clean it up.” Extraction cleaning can reveal the color, but a sealer can make it shine. “To get the color to pop, typically you put a film-forming sealant on the surface that really magnifies the color — it's like putting wax on your car.”
A good pressure washing is acceptable in some applications, Hicks says, because it will dislodge the debris from the porous concrete. The down side is there's water everywhere when you're done, and drying can take 48 hours — a window that allows more dirt to collect.
Even so, it's a good alternative in many situations. Manufacturers and contractors say that decorative concrete driveways, patios and walkways can be hosed down once a month or so, with a good pressure washing once or twice a year. Interior floors need only be cleaned with a bucket of soap and water and topped with a polish or wax. Floor scrubbing equipment should use long, soft bristles that won't scratch the concrete and sealers.
A pressure washer and a scrub brush also work well to clean joints and other hard-to-reach areas, such as decorative concrete applied with form liners or stencil overlays. Borum recommends warm water and low pressure, from 400 to 800 psi, which is enough to dislodge the debris but not too much to chip the surface. He recommends light detergents at low concentration, not acid mixtures, which can attack the concrete.
How often should decorative concrete surfaces be cleaned professionally to lift the dirt, grease and oil away? Experts say it depends on the conditions the concrete is subjected to, but if contractors educate their customers about the basics of regular cleaning, it will make the job easier when the professionals come in.
Sealers protect investment
Once the surface is cleaned and dry, it must be protected from the elements and from wear and tear with a high-quality sealer that repels water, limits damage from UV sunlight and resists abrasion.
John Maskas, technical director of SuperStone of Florida, says a solvent-based penetrating sealer is the workhorse for the residential market. Sealing for residential use is recommended every two years or so, but again that depends on the environmental conditions and wear and tear. “Just like there's not one application, there's not one answer,” he says.
The Florida sun can be particularly punishing to decorative concrete. Alex Metrovich, president of the Florida-based Innovative Concrete Technology Corp., says UV rays can break down the sealer, dulling the glossy finish and fading integral colors. A thorough cleaning and resealing can make the color look fresh again, but it's important that the surface be maintained properly from the start.
Borum warns that integrally colored concrete has its limitations. He's seen some projects fade in a matter of months because the materials were not carefully formulated. In addition to keeping a good sealer on top of the project, protecting it from UV and chemicals is critical to proper maintenance.
Nick Paris, vice president for marketing of Davis Colors, says the iron oxides in Davis' integral colors cannot fade. Integral colors can look faded if the concrete surface is worn away or because of efflorescence, the white deposit on concrete that's left behind when water moves through the material and evaporates, leaving salt on the surface. That's why maintaining a top quality sealer on the concrete surface is so important, he says.
Bob Ware, president of The Decorative Concrete Store in Cincinnati, Ohio, likes the effects of working dry-shake color hardeners onto decorative concrete. Hardeners increase the surface strength to 7,000 to 8,000 psi, and extend the life of the project. “By cleaning and resealing it, it's going to look just like the day you did it,” he says. “That's the beauty with the shake-on hardeners.”
Steve Adams, chief formulator for Seal Pro, Inc. Research Labs, manufacturer of sealers, overlays and curing agents in Medford, Ore., says a top quality sealer makes cleanup easier, improves the looks of a project and extends its life.
It's important to pick the right sealer for the job, he says. For example, some sealers are specially formulated so that gas won't seep through and oil stains can be wiped off with a rag. Look for a sealer that is specially designed for UV protection, or it may turn yellow over time. He also says that hydrophobic sealers keep water out of hairline cracks, preventing them from expanding during the freeze/thaw cycle.
Moisture another problem
Moisture intrusion is another enemy of concrete. Applied Concrete Technology Inc. offers a product that can penetrate concrete to form a permanent barrier against moisture. It waterproofs the concrete both internally and externally and needs to be applied only once.
Company co-owner David Johnson recalls selling Disney executives on the product, the Protecrete Densifier, when they were looking for a way to save sandstone and cement animals that were disintegrating in a water feature at Animal Kingdom in Orlando. Johnson took a crumbling turtle and sprayed on the Densifier, which reacted with the portland cement inside the turtle and solidified it. Since then, Protecrete products have been applied to all the concrete in Disney's theme parks and attractions.
Another product, the Mix Water Conditioner, is added at the batch plant to create a higher quality concrete that is more durable and less prone to cracking. Johnson says using both nontoxic products can also prevent efflorescence.
Contractors must understand regional conditions, products
Decorative concrete must withstand some pretty harsh conditions, and contractors must be experts on the environmental conditions of their area:
- Rain and Wind — Wind carries dirt, and rains break it down into tiny particles that can seep into the surface and stain it. A strong, steady wind in desert areas can sandblast concrete. Acid rain in polluted areas can erode it.
- Snow and Ice — Salt and chemicals used to melt ice in northern climates can allow moisture and chemicals to soak into the surface. When the temperature drops, the water freezes and expands, which can crack the concrete. Sand and salt from people's feet will scratch concrete.
- Sun — The sun's UV rays can degrade sealers, fade integral colors and bake stains into the concrete.
Manufacturers say contractors also must educate themselves on the products being applied to the concrete. Different products have different life cycles and maintenance requirements, and customers should understand that buying high quality products directly from manufacturers will cost more initially, but will save money over time.
Maskas, of SuperStone, says it makes good sense for a contractor to build a maintenance program into his original bid. “No. 1, it's a good way to keep him close to the people who can help him grow his business. No. 2, it can help him in term of growing his business with an existing job.” Customers are more comfortable dealing with the original contractor, so why send them to a competitor for a resealing job?
“Those are the upsides,” Maskas continued. “The down side is that it does take manpower away from perhaps a more profitable job.” If a contractor has the employees to handle ongoing maintenance, it will give him a competitive advantage, he says, but if the company isn't geared to it, don't over-commit and under-deliver.
Borum agreed. “If they're big enough and organized enough to make it a profit center, then by all means move in that direction.” But he added that it's important to market maintenance programs properly, or they can be a real drain on expenses. In some cases, contractors would be better off creating a relationship with another company that can do the maintenance work.
Metrovich says getting that repeat maintenance business can be as simple as sending a reminder postcard to the customer, just as a dentist will send cards out to patients reminding them to get their teeth cleaned every six months. He also suggested contractors could send out reminders when warranties are about to lapse.
Theo Hunsaker, inventor of Concrafter tools and the principal owner of the company, says that when a job is complete, the customer will receive a thank-you note with a photo attached. On the back is all the contact information the customer needs to keep their project looking as pretty as that picture.
He believes contractors should revisit their project sites every few years. That way, they can continue building their relationship with their customers while making specific suggestions for maintenance based on the conditions at that particular site.
Hunsaker, who has 50 years of concrete experience, says contractors should base their reputation on quality, not quantity. Contractors who are serious about their work and want to become leaders in the field need to take maintenance seriously too.