Help develop this article - click 'Edit this article' above.
Formwork is the term used for a temporary mould into which concrete is poured and formed. Traditional formwork is fabricated using timber, but it can also be constructed from steel, glass fibre reinforced plastics and other materials.
Timber formwork is normally constructed on site using timber and plywood. It is easy to produce, although it can be time consuming for larger structures. It is used when the labour costs are lower than the cost of producing re-usable formwork from materials such as steel or plastic.
Re-usable plastic formwork is generally used for quick pours of concrete. The formwork is assembled either from interlocking panels or from a modular system and is used for relatively simple concrete structures. It is not as versatile as timber formwork due to the prefabrication requirements and is best suited for lost-cost, repetitive structures such as mass housing schemes.
Stay-in-place structural formwork is generally assembled on site using prefabricated fibre-reinforced plastic. It is used for concrete columns and piers and stays in place, acting as permanent axial and shear reinforcement for the structural member. It also provides resistance to environmental damage for both the concrete and reinforcing bars.
Proprietary systems are used to support vertical formwork while concrete cures, consisting of a series of tubes and ties.
Once the concrete has gained sufficient strength the formwork can be struck (removed). A minimum value of 5N/mm2 is recommended in all cases when striking vertical formwork as so not to damage the permanent concrete in the process.
 Related articles on Designing Buildings Wiki
- Architectural concrete.
- Crane supports.
- Deleterious materials.
- Design liability.
- Facade retention.
- Health and Safety.
- Reinforced concrete.
- Slip form.
- Temporary works.
- Trench support.
 External references
- BS5975:2008 + A1: 2001 Code of Practice for Temporary Works Procedures and the Permissible Stress Design of Falsework (BSI 2011).
Featured articles and news
Futurist Thomas Frey explores the concept of Disposable Housing - could it be a reality sooner than we imagine?
ICE to host new exhibition offering a window onto the civil engineering achievements beneath our feet.
Do you know all the various types of defects in brickwork?
US museum reveals plans for an installation made entirely of paper tubes.
Review of a book looking at how contemporary architecture found its expression within neoliberal capitalism.
The Great Mosque of Djenne, the largest mud-brick building in the world.
Amanda Clack, RICS President offers recommendations to government on Brexit and the construction skills shortage.
Tired of the commute? This architecture firm believes the best solution is to take cars underground.
Why do so many women leave engineering? Probably not for the reason you’re thinking.
For over 30 years David Trench was one of the UK's leading project managers. Read about his career through some of his most famous projects.
Leading institutes join forces calling for property flood resilience measures to help householders avoid repeat flooding.
CITB publish new report calling for the development of new skills standards for offsite construction.