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
- 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
5 out of 10 filtering facepieces fail HSE tests.
Eleven Magazine announce the winner and runners-up in their Moontopia competition.
As January is the time for hitting the gym, Designing Buildings Wiki lists the best gym architecture in the world.
London is at the top of the list of global construction megacities, beating Dubai and Abu Dhabi.
What are the innovative business models of the future, and how to incentivise supply chains to work on a whole life basis?
One of the largest churches in the world, the monumental St. Peter's Basilica.
How thermal comfort is quantified and how it can affect wellbeing.
Snøhetta complete a treehouse cabin that allows guests to lie beneath the Northern Lights.
Christiania is an anarchist 'freetown' in Copenhagen where strange and experimental architecture has flourished.
Why buildings crack, how cracks are categorised and what can be done.