The integrally colored work can also be chemically stained. Jon Nasvik suggests using two or three stain colors diluted with water to achieve a natural look. “The result of our idea makes patterned concrete installations much faster and easier,” he says.
Water features with GFRC “If you can’t go to the mountains every day, we can bring a portion of the mountain to you,” says Ross Connors, president of RC Concrete in Puyallup, Wash. He makes glass-fiber-reinforced concrete (GFRC) rock and waterscapes. His methods include building hand-sculpted and chemically stained rock forms, molding rock by shotcreting GFRC concrete ¾ inch thick inside a mold, and making 6×8 panels to join for large boulders. All the hand-sculpted rock is reinforced with polypropylene fibers, steel reinforcing bars, and metal lathe. To texture the mold, the company sometimes adds a different aggregate, such as granite fines, and uses an acid wash for a grainy look. Some designs include rock that hangs over the pool edge or comes right into the pool. GFRC rock can be cut or shaped to meet any design. For water features, pipes are placed in the mold as they are shot with concrete. “Concrete rock is unique because you can direct water through it in an infinite number of ways like sideways cuts so the water comes out as sheets, or by drilling holes so the water weeps. You can’t do that as easily with real rock. An actual rock could splinter or crack, especially when it’s moved. When there is no access for machinery, you can put GFRC rocks into a wheelbarrow and then lift them into place. If owners want a rock incorporated into their concrete patio, real rock can cause cracking. But with GFRC rock, you can put the rock on top of the concrete. The lighter rock does not distress the concrete,” says Connors.
A word about sealer Two types of sealers for pool decks and patios are film-forming and penetrating. Both may be water-based or solvent-based, and, depending on the sealer formula, can resist water, oil, and grease. Film-forming sealers leave a thin barrier on the concrete surface like a colorless paint, or the sealer may be tinted. Penetrating sealers flow into the concrete’s pore structure without leaving a residue on top.
“Most people choose sealer for the look they want and the protection they need,” says Bert Adams, president of Glaze ‘N Seal. Adams’ experience is that most people prefer film-forming sealers because of their more finished look, deepened color appearance, and range of gloss.
Another advantage of film-forming sealers is that they protect against the acid in pool chemicals that attack the concrete. A penetrating sealer has no top barrier to resist chemicals. A big issue for pool decks and patios is good traction when the surface is wet. With film-forming sealers, a lightweight micronized polymer such as Shark-Grip by Sherwin-Williams can be introduced into the product. The polymer remains invisible and suspended in the sealer, producing a foot-friendly, slip-resistant texture. All sealers need occasional renewal for optimum results.
More creativity Ralph Gasser, owner of Concrete Designs by Gasser in Redding, Calif., has created a tool called the Shasta Seamless texture mat, one of the first large texture mats in the imprinting industry. It was later manufactured and marketed by Brickform under the name Sierra Seamless.
Gasser pushes the design boundaries of decorative concrete, sometimes forming edges and then kicking concrete into free-form shapes, or breaking edges after installation to soften them up. He uses materials ranging from aluminum foil to string to create new surfaces or imitate the grain of a rock. For example, he places a 5-gallon bucket in the middle of a pad and walks a string around it to create an irregular concentric circle patio design.
Because manufacturers develop new products, and both seasoned professionals and new contractors creatively explore their use, decorative concrete’s expansion appears unlimited. “It’s the science of technology and the art of application that make decorative concrete what it is,” says Brickform’s Branum.
This article first appeared in RESIDENTIAL CONCRETE magazine.
