Formwork design can be simple and straightforward when the designer understands the fundamental structural requirements of each member making up the forming system. Each piece of wood or plywood in a deck forming system must meet standard limits for bending, deflection, and shear. Once these requirements are met, a structurally sound forming system can be built.
By doing design calculations for commonly used sizes and grades of materials and combining the results in a series of charts like those presented here, designers can avoid tedious recalculations and get some answers in a few minutes. These charts are much like the ones published in the April 1984 issue of Concrete Construction, except that they cover formwork for horizontal instead of vertical structural members.