A form liner is a type of mold used to create textures or patterns in the surface of concrete. These liners help to replace boring, gray concrete with more aesthetically-pleasing finishes. A form liner can be used to give cast-in-place concrete the look of brick, stone, or even wood. It can also be used to create a virtually unlimited array of textures, or even to cast custom logos and designs in a concrete surface. These types of concrete finishes are often used to decorate bridges, highway sound barriers, and even patios or floors.
Before using a concrete form liner, builders must first construct traditional concrete forms out of wood or other materials. These forms hold the wet concrete until it dries, or cures. The form liner is place inside the form and held in place using special clips or fasteners. Next, the concrete is poured into the form and allowed to dry completely. Finally, the form and form liner are removed, leaving the pattern of the form liner stamped into the surface of the concrete.
Both disposable and reusable liners are available for builders to choose from. Disposable units are made from foam or cardboard, and are designed for a single use on small projects. They tend to be fairly affordable, but cannot be used to make deep-set impressions in the concrete. Reusable liners are generally made of rubber or polyurethane, and are more effective at creating deeper patterns and textures. These liners cost more than disposable units, but can be cleaned and reused indefinitely.
One appeal of concrete form liners is the wide variety of design and finish options they can be used to create. By using the same form liner or adjacent sections of concrete, users can produce a uniform and consistent design pattern across a larger structure. These liners also allow contractors to cast and finish concrete in a single step, which can save both time and money.
Before using a form liner, consumers should be aware of the potential limitations of these tools. When used to mold a series of adjacent sections, the joints between each section can be hard to hide. These forms also come in limited sizes, and special sizes or custom designs tend to be more expensive than standard models. Finally, concrete form liners may require builders to use special forms or concrete mixtures in order to produce the desired results.