Shuttering is a term used to describe the process of building formwork, or temporary containment structures, used in the process of pouring concrete. Concrete shuttering is done to help give the concrete a form while it is setting, thereby preventing leaking, cracking, or uneven surfaces. Wood can be used to shutter concrete, as can metal structures known as roadform. The pieces of shutter material are kept in place with rods and other security components known as falsework that can be removed once the concrete has been set. Most formwork is temporary and will be removed once the concrete has taken shape.
The process of concrete shuttering starts long before the concrete is even poured. First a plan must be developed to determine where the pieces of formwork must be placed; this is usually done by drawing up a blueprint. Then it must be decided what type of shuttering will be used. Water-resistant plywood is a common choice, though in some cases, metal roadform can be used. Plywood is less expensive and usually easier to store and transport, so it is the more common choice for most projects. Once the plan has been developed, the formwork can be put in place and falsework can be used to secure the forms in place.
This is not a quick process, and it is likely that several workers will end up placing the shuttering on larger projects. The formwork must be checked and double checked to ensure it is placed properly and all angles are tight. This will prevent concrete from pouring out of gaps between forms, and it will also help ensure all faces of the concrete will be flat and straight after it cures. Once the concrete has set, the forms will need to be removed and cleaned so they can be used again for future projects. In some cases, the plywood may not be reusable, so it will be discarded after use.
Shuttering can be a fairly complex task, especially if especially tall forms must be built, or complex foundations with many angles or circuitous paths. Builders are usually specifically trained to build formwork ahead of a concrete pouring project, and in some cases, the shuttering carpenter may have a hand in the actual pouring of the concrete to ensure the forms are properly placed throughout and do not shift as concrete is poured. If necessary, small adjustments to the forms can be made during the pouring process.