Creative Concrete Options
Open New Era of
Pool Decking Design

By Karin Marie

Young children run on it while playing. Teenagers lie on it while gossiping with their friends. Adults use it for parties and tell their kids to "walk, don't run," on it.

Most people probably don't give it much thought. Their focus is on what it surrounds - a large hole in the ground full of clear, sparkling water. But the deck is a swimming pool's setting much like a ring is the setting for a diamond. It can be purely functional, or it can be functional and beautiful.

Pool deck styles vary around the country. In the Southwest and Florida, the palette leans toward pastels and terra cotta with sandstone and stucco finishes. The Mid-Atlantic region favors slate and bricks, while the Midwest embraces all types of stone and slate, noted Greg Lamm, director of marketing and product development at Decorative Concrete Finishes. These regional preferences represent a wide range of designs, colors and materials. In addition, pool decks present a unique set of challenges because of the presence of water, oily lotions and chemicals. The decorative concrete industry has applied itself to developing products and techniques that stand up to tough poolside conditions, while offering dazzling aesthetics.

Both cast-in-place concrete and concrete overlays - concrete-polymer mixtures poured in thin layers over a concrete base - provide a foundation that can be worked into a multitude of effects. These include faux stone, brickwork, tile, aggregate, textural finishes and contemporary designs such as geometric patterns.

Among the advantages of using concrete-based systems for pool decks are cost savings, material availability, construction time, durability and flexibility. "In terms of cost, using concrete involves less time and labor," Lamm said. "Cost savings also come into play when homeowners want the look of a material that would be expensive to import from another location," said LM Scofield's Bobby Harris, former contractor who works in product development and testing.

"Concrete emulates the look of stone or tile without the cost," added Tom Blumenkamp, of Wise Pools, a major pool construction company.

Because concrete is readily available, homeowners don't have to wait for delivery of natural materials. Installation time is cut dramatically over that of laying stone, slate, tile or brick. Being a malleable substance, concrete can be shaped into realistic-looking imitations of natural materials using techniques such as stamping (imprinting damp concrete with a pattern) and etching (cutting patterns into the concrete).

Concrete also offers other options. If they prefer, homeowners can let their imaginations run wild with unusual textures, geometric patterns, graphic images, aggregates and fluid, curving forms.

According to Blumenkamp, highly contemporary looks can be achieved by pouring concrete, allowing it to harden and then etching, or cutting, patterns into it. "Etched patterns can be linear, geometric, rounded or three-dimensional," Harris said. Homeowners who really want to express themselves can do so by sandblasting water-related images, such as dolphins, fish or shells into the dried concrete. They also have the option of adding real shells to the concrete as an aggregate.

Among currently popular textures, noted Harris, is a rock salt surface, best suited for warm climates. Chunky rock salt is mixed into the concrete before it is poured, then after the concrete dries it is washed out with water, leaving behind a pocked surface. Not only is this texture appealing to the eye, it's also practical. "The small holes create air pockets that keep the concrete cooler," he said. "This makes the surface more comfortable on bare feet."

Concrete even has an edge over many natural materials because it can be used in designs with curves and rounded areas. These can be difficult, or even impossible, to do with a material such as stone. Concrete is sometimes used in the creation of water features such as rockscapes, fountains or waterfalls. It is also a good choice for creating a slope, which is used in the newly popular beach or slope entry to pools. Instead of building a wall at the pool's shallow end, a gentle incline leading into the water is constructed. It grows gradually deeper, similar to the beach as it meets the sea.

Colors in decks are achieved by different methods, depending on the type of system being used. In some cases, pigment is mixed in with the concrete material, in other cases it is spread over the surface. Acid stains, which penetrate the concrete, can be applied to the surface and create yet another effect.

Homeowners often express concern over concrete's durability, Lamm pointed out. Durability issues include the material's strength, its lifetime, as well as how it stands up to pool chemicals and weather exposure. The concrete used for pool decks is a specially developed mix that includes ingredients that actually make the material stronger than normal concrete. "Our products grow stronger over time as the concrete ages,„ Harris said. "They are also UV resistant so the sun won't fade the color or degrade the material."
Lamm, whose company makes concrete overlay systems, noted that problems like grout joint failure between stones or bricks are unknown when using concrete to simulate these materials. Overlay systems are used in conjunction with cast-in-place concrete. The deck is poured as usual - with one exception. It is kept slightly, shallower than it needs to be. The overlay material, a concrete-polymer mixture, is then poured over the concrete base to a depth of one-quarter to three-quarters of an inch. Before it dries completely, it can be textured to look, for example, like stucco or stamped to simulate stone or brick.

One of the advantages of the overlay system is that it is a two-step process "It can be relatively difficult to get the deck concrete placement right," Lamm said. "Then it's that much more difficult to do the stamped process at the same time. With the overlay you have more time to work with it and can be very meticulous with the stamping."

Homeowners often wonder if the overlay might come loose from the concrete foundation. "Because of the way the products are designed, Lamm said, "they bond tenaciously. When being used on old decks, it is very important to correctly prep the concrete surface so that this bond occurs. The old concrete is first given an acid bath that loosens the top layer, which holds dirt and oils. This is neutralized and washed away. In some cases, a degreaser may be necessary to remove deep stains. Once a clean, fresh surface is created, the overlay is applied."

In a similar vein, new or freshly cleaned concrete deck surfaces can be treated with a penetrating acid stain. An engraving machine is used to etch a shallow trough through the stain level to the concrete below. The exposed gray concrete looks like grout. This technique can be used to make geometric patterns or simulate the look of brick, flagstone and tile.

Safety is a huge issue with pool decks, particularly in the area of slip-resistance, Harris noted. Decorative concrete applications, such as floors or countertops, are usually topped with a sealer. In the case of pool decks, where water is a factor, some manufacturers recommend not using a sealant. Another solution is adding a substance to give the sealant a grip factor. "We place silica in our sealant, which helps with slip resistance," Lamm said.

Concrete's popularity as a deck material is definitely on the rise if you measure it by the increase in the number of booths devoted to this technology at pool industry trade shows. New advances and improvements in terms of aesthetics, functionality and durability are expected to accelerate this trend.