When constructing a building, contractors turn to formwork to provide the necessary structural shape for the concrete being poured. However, this serves as only one type of formwork used today, and some nations across the globe refer to this as shuttering. The formwork remains in place once the concrete has been poured to hold this material in the correct shape until it sets and obtains the initial strength.
Shapes and Sizes
Formwork can be created in a variety of shapes and sizes, depending on the needs of the project. The construction of the form takes time and accounts for up to 25 percent of the cost of the structure. When constructing a bridge, the cost increases more. As a result, contractors look for economical ways to create forms, such as by using stripped formwork. Stripped formwork involves the use of forms that have been removed from a previous job. Contractors refer to reusable forms as panel forms and one-time use forms as stationary ones.
Materials Used in Formwork
Contractors find they may select from a range of materials when requesting formwork. Each material comes with benefits and drawbacks contractors must consider before choosing.
Timber Formwork: Timber formwork remains the most common choice, as it can be constructed to meet the needs of the project. It is lightweight, making it easy for employees to manage, and it offers thermal resistance. This remains import in cold areas. Skilled labor isn’t required to construct the forms, as they are very basic and the construction process is easy to understand. Nevertheless, dry timber contains moisture, which can make it difficult to work with. Contractors can only modify the formwork a handful of times, and timber with a higher moisture content could result in wet concrete and the resulting issues.
Plywood Formwork: Plywood is a waterproof formwork option and is very economical. Contractors find they can use it repeatedly as long as the forms are properly erected and removed. The plywood holds up well under intermediate weathering situations and has a solid surface. The plywood formwork can easily withstand the loading of the concrete and is smooth and simple to use. This ensures a flat surface finish for the project. Contractors enjoy being able to cut the plywood to the appropriate scale for each project.
Steel Formwork: Manufacturers create steel formwork by joining thin steel plates using clamps, bolts, and nuts. They are made in either modular form or scale, and both types provide a long lifecycle along with better replication. These forms are very robust and can be quickly assembled and removed. They serve as a cost-effective option for large projects and won’t shrink or warp with time. Contractors appreciate the consistency of the finished surface thanks to the smooth surface of the steel formworks, as the resulting concrete doesn’t require further treatment. However, contractors pay more when they choose this option, and the steel forms are very heavy. Moving equipment must be used to lift a panel. Furthermore, steel formwork is limited in both its form and scale.
Aluminum Formwork: Aluminum and steel formwork share many similarities. The major difference lies in the weight of aluminum forms and the cost per project. Aluminum forms take less time and fewer resources to construct and provide a clean surface finish. One form may be used up to 250 times before it needs replacing, and this option is very cost-effective when symmetrical buildings are to be constructed.
On the downside, the forms take more time to set up, and they must be properly maintained and aligned by professionals. Furthermore, any holes created in a wall tie must be properly addressed. A failure to do so will lead to leaks in the future.
Consider all formwork options for your next project. Contractors find they use different materials for forms depending on the work to be completed. By researching all options, you can ensure the right formwork is selected every time.
