Formwork is a temporary or permanent mold used in concrete construction to support and shape freshly poured concrete until it gains sufficient strength to support itself. It is typically constructed from materials such as wood, steel, aluminum, or engineered plastic systems, and is designed to withstand the lateral pressure of wet concrete while maintaining dimensional accuracy.

Formwork systems can be categorized into several types:

• ‌Traditional timber formwork‌ – Custom-built on-site using wooden planks and supports; flexible but labor-intensive.
• ‌Steel formwork‌ – Reusable, durable, and suitable for high-rise or repetitive structures; offers smooth surface finishes.
• ‌Aluminum formwork‌ – Lightweight, fast to assemble, and ideal for standardized elements like walls and slabs.
• ‌Modular or system formwork‌ – Prefabricated panels with standardized components (e.g., table forms, tunnel forms); widely used in commercial construction for efficiency.
• ‌Slipform‌ – Continuously moving formwork used for vertical structures like silos, chimneys, or bridge piers.

Proper formwork design must account for load-bearing capacity, stability, waterproofing, and ease of removal. After concrete curing, the formwork is stripped — a process known as striking — typically after 7 to 28 days, depending on mix design and environmental conditions.

The quality of formwork directly impacts the final concrete surface finish, structural integrity, and project timeline. Modern practices increasingly favor reusable and sustainable formwork systems to reduce waste and cost over the lifecycle of a project.