A formliner can give concrete a distinctive look, and can be a cost-effective way to bring artistic appeal to a variety of construction projects. Before getting started, you should learn the basics about two popular types of formliners. Most formliners on the market today are made from urethane or plastic (single use styrene, or multi-use ABS). Each material offers advantages and disadvantages which should be considered before you plan your project.
Texture and Realism
Depending on the pattern or texture, you may notice a significant difference in the finished appearance of concrete that’s been cast with a urethane formliner compared to concrete texture created with plastic formliner. Generally speaking, urethane offers a more detailed texture, while plastic formliner creates a more diffused look. This difference is due to the way each type of formliner is made. Urethane formliners are made by pouring liquid urethane on the mold’s surface. The urethane liner cures, and picks up every nuance of the mold. When finished, the concrete texture created by a urethane liner looks exactly like the master mold. Plastic formliners are made by heating a sheet of plastic to a pliable state, then vacuuming it to a mold. As a result, plastic formliner offers a muted version of the urethane liner’s finite detail.
For the most part, plastic formliner comes in 4″ x 10″ rectangular sheets, and are made from only one mold. When cast on large unobstructed surfaces, the single mold pattern creates an evident rectangular repeating pattern across the surface face. On the other hand, urethane formliner is available in many different sizes and made from 2-6 different molds of the same pattern that match up on all sides and even when inverted. Given this flexibility, pattern repetition can be easily avoided and aesthetics are preserved.
Urethane: Extremely durable, urethane formliner has the potential to be reused multiple times, given proper care. In addition, urethane formliner fits snugly together on the form, and requires a minimum of caulking to prevent leakage along seams. Custom Rock offers two grades of urethane liner:
–Duraform: Made from solid urethane, Duraform offers the highest reuse potentail available
–Hi-Lite, Multi-Lite, and Cut-Lite: Made with a solid urethane skin and backed with urethane foam, these grades of urethane formliner offer lower reuse capabilities at lower prices, which may be ideal when the project requires that the formliner needs to be cut or trimmed to account for design elements, texture truncation, or elevation changes. These grades of liner are completely interchangeable with Duraform in the same pattern. Depending on the project, a mix of different grades of urethane can make the project more cost effective for the contractor.
Plastic: Plastic formliner is available in two different materials: single use styrene, and multi-use ABS. As the name implies, single use styrene is simply that – made for one pour. ABS, on the other hand, provides up to ten reuses, depending on the pattern, handling and jobsite conditions. Most plastic formliner is available in 4’x10 sheets, and all seams must be caulked. Additionally, we generally recommend backing plastic liner along any areas that depart from the form.
This is where the rubber meets the road. Looking strictly at per square foot price, plastic liner is always less expensive than urethane liner. However, when taking into account the applied square footage cost (total project square footage/liner reuse factor) and project conditions, urethane may be the most cost effective liner material. Furthermore, you must also consider the additional labor in replacing broken plastic liners: cleaning the form, reattaching the liner, backing it, and sealing it. Depending on the size and nature of the project, and depending on the architect’s specification, one material may be more suited for a particular project than another.
Before ordering formliner for your project, consider the demands of the specification as well as the impact that reuses could have on your project. Feel free to contact us – we’re always happy to help.