Creating Unique Concrete Form Liners

In communities across the country, ordinary concrete walls are being overtaken by everything from slithering lizards and leaping bluefish to giant cacti and rambling freight trains. But residents aren’t apprehensive; they’re thrilled.

Rather than monstrous monoliths of flat concrete looming on the horizon, extraordinary three-dimensional creations are popping up in cities and suburbs, along highways and beaches, next to mountains and in deserts — as one-of-a-kind works of art.

Form liner of fish are ready to be set with wood and then filled with concrete.

Wood backing on a skate park ready to receive concrete.

Finished concrete wall with imprinted skate boarder silhouettes.

Participants agree that a lot of planning goes into these massive public projects, which usually involve highways, sound barriers and retaining walls. Depending on the scope of the project, the team may consist of architects, engineers, artists, general and concrete contractors and form-makers who work with the contracting government agencies and neighboring communities.

Simple technique brings great results
Whether the project is large, small or somewhere in between, “We [artists] like to be brought in at the beginning,” says Lilli Ann Rosenberg, an artist from Jacksonville, Ore., who together with her husband, Marvin, has been working with concrete for more than 30 years. The two have been commissioned to dream up designs for such projects as skate parks, libraries, schools, playgrounds, hospitals, health clinics and housing developments.

Colorful highway wall treatment including a salamander made possible by concrete form liners. Decorative walls by Scott System.

Small planter with fish, butterfly, and bird silhouettes waiting for concrete

Lilli Anne Rosenberg removing pink foam mold to reveal a skate boarder silhouette in concrete wall.

Once the conceptual drawings have been done and the design approved, the couple use rigid insulation boards to make their decorative forms. Their technique is quick and easy, Lilli Ann says.

She draws the images and Marvin cuts them out. They glue whole boards or pieces together for extra dimension and use a soldering iron to create textures and patterns. Next, the Rosenbergs take the carved panels to the site, where they glue or screw the carved insulation panels to the plywood forms before the concrete is poured.

Concrete wall with imprinted cacti with red dots created by using concrete form liners and detailing with concrete stain. Decorative walls by Scott System.

Concrete form liner being made and cut out by concrete contractors images of  sea turtles. Decorative walls by Scott System.

Sea turtle in concrete wall molded by concrete form liners. Decorative walls by Scott System.

Lilli Ann says they first coat the carvings with liquid soap for easier removal. “When the concrete is totally cured, in the next day or so, we pull out the foam. Sometimes we have to power wash the design to get out all the little pieces.”

It’s a fast way to make a flat, boring wall into something very attractive, Marvin says. And as soon as one job is done, he adds, there’s another one waiting. “We’re constantly getting business.”

A mold for every need
“Architectural concrete is here to stay,” agrees Buck Scott, founder of Scott System, a Denver-based firm that has played an important role in helping to advance concrete art technology. “It’s becoming more and more prevalent in the marketplace. And people are demanding more intricate designs and patterns than ever before.”

Concrete form liners can create a concrete canvas - fresh form liner for a skate park>

Concrete column with the imprint of two sword fish made by using a concrete form liner during the construction. Decorative walls by Scott System.

Concrete form liner of grapes and grape leaves on a vine. when used in a concrete form, the grapes will leave an image of the vine on the concrete.

Back in 1969, Scott introduced the industry’s first elastomeric urethane form liner, which mimicked the look of rustic wood in very fine detail. Today, Scott System can replicate more than 700 textures with molds the company has created from this pliable material. Plus, they can custom-produce virtually any image or logo by utilizing the talents of staff members and of sculptors and artists across the nation who are specialists in concrete art.

The process begins with conceptual drawings, which eventually evolve into sculptured creations. The sculptor first creates the original work using a medium such as clay, plaster, urethane or wax. From this masterwork, a cast is made using a synthetic liquid rubber. Finally, from this cast, elastomeric urethane form liners are created in the reverse image of the original.

Elastomeric urethane forms can be used 100 times or more. “That’s the key. They are reusable,” says Scott. “They’re not for small jobs or one-time use.” He estimates the forms can cost anywhere from $12 a square foot to $120 on up. “It all depends on the depth of the liner, how deep the texture is, how much rubber is used.” Overall, the more involved the pattern, the more expensive the liner.

Abstract flower with lined wall in concrete made by using a concrete formliner. Decorative forms by Greenstreak Inc.

Inca design imprinted into a concrete wall during placement using concrete formliners.

Bridge support beam made from concrete with a star inside a circle made using a form liner during the concrete pour.

Scott System has produced form liners for a variety of public arts projects, with some liners more than 110 feet long to avoid joint lines. These form liners are so big, Scott says, that contractors have to handle them with cranes.

To fabricate the actual artwork, crews use a cast-in-place technique, pouring concrete into preconstructed vertical molds at the site. The process involves setting the forms, installing form liners inside the forms, pouring colored or plain concrete and then stripping the forms. Some jobs involve staining the concrete artwork.

In addition to elastomeric urethane forms, plastic form liners are produced by a handful of companies, including Greenstreak Inc. out of St. Louis, a company that’s been in the concrete construction business since 1951. “The architectural market has grown so much,” says Kyle Loyd, technical sales engineer. Greenstreak entered the form liner business some 20 years ago, and it’s now one of their main products.

Highly detailed textured abstract are made in concrete by using a concrete form liner.

Abstract art placed into a concrete wall by using a form liner during the forming of the concrete.

Large roadside sign logo made of concrete by using a concrete form liner. Decorative forms by Greenstreak Inc.

Although Greenstreak’s designs aren’t as intricate as the ones created by Scott, the company offers 30 different stock form liners and will create logos to order. “We’re trying to get more involved in the design aspect of the business,” Loyd says, “and fit the needs of the industry as it changes.” The company provides one-time plastic and multi-use rubber form liners for tilt-up, cast-in-place and precast concrete applications.

Computers assist in design and fabrication
J.D. Moore, owner of Concrete Artforms in Charleston, W.Va., says he, too, has been producing architectural concrete forms for nearly 20 years, but he deals only with custom orders. His projects have ranged from the very small, such as residential signs, to extensive works including citywide flood control walls that depict local history.

“The things we’re doing now are more complicated and more formed than in years past,” he says. He now has the ability to make formwork in one piece or to devise a design that can be curved around a hillside. “We can do both positive carvings and negative reliefs,” he says. “The progression has been slow but steady and we’ve learned a whole lot in the process.”

Wood is all that is remaining of the formliner used to create a large sign with the silhouette of leaves. Decorative forms by Greenstreak Inc.

Concrete wall created using a form liner of a mail buffalo. Decorative walls by Scott System.

Abstract acorn in concrete made by using a concrete formliner. Decorative forms by Greenstreak Inc.

Depending on the individual clients’ budgets and needs, he makes his one-of-a-kind forms with everything from insulation board, rubber and hardboard to cardboard, wood and polyethylene foam of various densities. “We make it our business to match the job to the materials we select for the form in order to provide the highest quality possible,” he says, always mindful of the cost.

Moore creates many of the designs himself. Clients typically provide a rough illustration or a description of what they want and he uses his computer to build a three-dimensional design.

“Most of our sign work is done with a computer,” he says, adding that computerized routers are used to make the master molds in his fabrication shop. Sometimes, he explains, the routers — “which can be really precise” — can do the whole job; other times he finishes the design by hand.

Wall stained pink with blue waves imprinted during the forming process prior to pouring the concrete.

Concrete form liners can be used on bridges to match the surrounding area.

Bright blue concrete waves on a parking lot wall made with the use of concrete form liners.

“We use the latest computer design software, which is compatible with the wide variety of cross-platform formats used in the design industry today,” he says. And his forms, he adds, are precision cut using CNC (computer numerical control) machinery.

Some of Moore’s artwork is precast, such as when he creates signs that involve multiple pours and several colors, while others are poured on site. Although various levels of relief will normally be enough to define most designs, Moore says he frequently uses color and textures to enhance the final product.

“Concrete is not a perfect material,” Moore concedes, “so you never really know what’s going to happen to it.” But you can be sure that the outcome will be a creation that all can enjoy.

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