There are two types of formwork sheeting.
Formwork bearers directly support formwork sheeting. They carry off the forces through falsework structures to supporting members, the soil and formwork ties. The formwork bearers normally consist of squared timbers. The cross-sections of the beams depend on the loads to be resisted. Because of their good workability, wooden beams have a wide field of application. In addition to wooden beams, prefabricated steel parts (steel beams, clamps, etc.) are also used. Clamps are mainly used for column formwork.
With vertical formwork, the horizontally acting formwork pressure is mostly taken up by tieing the two formwork faces to each other by formwork ties. It is done by slinging a steel wire (3.1 mm to 4.2 mm, annealed) around the formwork bearers, guiding it through boreholes in the formwork sheeting and tightening it by twisting. Immediately near the tie wire, a stull (of wood or concrete) is to be mounted to maintain the necessary width of formwork.
When placing the concrete, the stull (if made of wood) is to be removed because the concrete mix assumes the bracing function (pressure). Another way of bracing is screwing by means of steel screws.