# What is formwork in construction?
**Formwork is a temporary or permanent mould into which wet concrete is poured and held in place until it cures and gains sufficient strength to support itself. Also known as shuttering, formwork determines the shape, size, surface finish, and position of the concrete element. It is one of the most critical components in concrete construction, as poorly built formwork can lead to structural defects, misalignment, or even collapse.**
## Application
Formwork is used wherever concrete needs to be cast into a specific shape — foundations, walls, columns, beams, slabs, and even complex architectural curves. The choice of formwork system depends on factors such as the type of structure, the number of times the formwork will be reused, the required surface finish, and the project budget.
The most common types of formwork include:
– **Timber formwork** — traditionally the most widely used type, built on-site from plywood panels and sawn timber. It is flexible and economical for small projects or irregular shapes, but labour-intensive and limited in reuse.
– **Steel formwork** — consists of prefabricated panels that can be assembled and disassembled quickly. It provides a smooth concrete finish and can be reused many times, making it cost-effective for large or repetitive projects.
– **Aluminium formwork** — lightweight and easy to handle, commonly used for residential buildings with repetitive floor plans.
– **Plastic formwork** — modular, lightweight panels suitable for simple concrete structures, often used for low-cost housing projects.
– **Insulated concrete formwork (ICF)** — permanent formwork made from expanded polystyrene that remains in place after the concrete cures, providing built-in insulation.
Proper formwork must be strong enough to resist the pressure of wet concrete, rigid enough to maintain its shape, and tight enough to prevent leakage. It must also be easy to strip without damaging the cured concrete surface.
## Related terms
– Concrete
– Formwork release oil
– Reinforcement
– Curing
– Shuttering
– Falsework
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