The Benefits of a Reusable Concrete Formliner

Learning more about reusable concrete formliner materials may help you decide if your project can benefit from using them. These tools are used in the construction industry to mold plain concrete into decorative concrete pieces. They are a cost-effective way to mimic expensive materials, such as brick, stone, and wood, using concrete. They can be used in a variety of cast-in-place, precast, and tilt-up jobs to enhance bridges, parks, residential areas, and other architectural concrete projects.

When choosing the best form liner material, you’ll want to consider how many times you want to use it. The types of materials used to make them play a big part in their longevity. Some materials are made to withstand hundreds of pulls, but others are only good for one use.

What Is a Reusable Concrete Formliner?

What separates reusable liners from single-use ones is their ability to generate multiple pulls before they wear down. Reusable formliners are made of stronger, more durable materials that last longer as long as they are properly cared for between uses.

What Is It Made Of?

No matter what material you choose, a good way to preserve a formliner for reuse is by applying a release agent before each use to limit adhesion to the concrete. The 4 main materials used include:

1. Urethane Rubber

Among all the materials used to make concrete formliners, urethane is the best option for reuse. It is a very high-quality, durable, and flexible material that is poured over a master to create panels of various shapes and sizes. It is the only material with multi-reuse potential, as a single liner can achieve as many as 100 pulls.

Urethane is great for custom patterns with high detail and depth, custom panel sizes, and, most importantly, large projects that require high reuse. Also, when it is bonded to a plywood backing, it makes it easier to move and work with.

2. Foam

As a lightweight material, polystyrene foam is easy to use and trim to the size you desire. It can be either hot wire cut or molded to generate a smooth finish on concrete, but it is generally limited in the shapes it can create if you intend to reuse the mold more than once.

It is a decent alternative to urethane rubber, but it must be coated with a 2-part urethane encapsulant of some kind, or it will be destroyed in the stripping process after one use. For this purpose, VFI offers VFI-2538 70 D EPS Form Hard Coat, which creates a uniform and releasable surface when casting concrete. When coated, foam liners can be reused if maintained, but they will not produce nearly as many castings as urethane rubber.

3. Plastic

The number of uses you’ll get from plastic will depend on the type of plastic used and its thickness. Plastics such as styrene and ABS are used in form lining, but only ABS is capable of multiple uses (usually up to 5). While it’s more cost-effective, it won’t provide nearly as many pulls as urethane.

Plastic formliners also provide concrete with a subtle, less detailed finish since they are made using a vacuum-forming process. Plastic is a desired material if you’re working on smaller projects where only basic patterns are needed and high reuse is unnecessary.

4. Fiberglass

Concrete formliners were once made of fiberglass sheets fastened to a form to create basic ribbed patterns. As new materials and techniques emerged, fiberglass took a backseat in the industry since it was much more time-consuming to use. Urethane rubber is easier to work with and produces results just as good in most applications. If more than 3 inches of relief is needed, fiberglass is preferred, though urethane is capable of high reliefs as well.

Benefits of Urethane Rubber

• Cost efficiency – While urethane rubber is a more costly material, its reuse potential more than makes up for the initial cost. With proper cleaning and storage, you’ll be able to maximize the life of your reusable concrete formliner.
• Durability – Most urethane formliners are made of solid rubber, so they have the strength to endure multiple pulls. The best reusable ones use higher durometer urethanes, typically between 70A – 90A. The harder the material, the more capable it is of maintaining its strength over time.
• Flexibility – Urethane can be more flexible or rigid depending on what kind of incuts you require in the design of your formliner. This increases the design potential you have while the material maintains its reusable nature.
• Versatility – Unlike other materials, urethane can copy extreme detail from a master and transfer those details onto wet concrete. You’re then left with concrete pieces that have the realistic finish you desire. There’s no limit to the concrete textures, patterns, or designs you can create with urethane. It is also capable of creating reusable concrete formliners of any shape or size needed.
• Consistency – Because urethane concrete formliners have such high reuse potential, they produce repeatable, uniform patterns after each use. Urethane reflects the same amount of detail in every cast, so large projects are desirable and seamless.

VFI Urethane Rubbers

VFI manufactures various urethane rubbers for the creation of reusable concrete formliners. Depending on the detail desired, we generally recommend the 50A-90A rubbers in our 2100 series. Our VFI-3170 and VFI-3180 rubbers are also excellent materials but must be used in controlled, high-production environments. If you’re interested in either product line, contact VFI today for more information.