In selecting the formwork system, the contractor wants to consider such things as:
- Safety.
- Available labor skills.
- Availability and type of form material and handling equipment needed.
- If custom forms are to be used, whether rental or purchase is preferable.
- Size of modular units (typically, it’s best to use the largest size possible with the lightest weight).
- Number of concrete placements and likely amount of reuse of forms.
- Comparison of hand-setting of forms with gang forming.
- Number of pieces of hardware and miscellaneous items to handle.
- Finish specified for the concrete (which affects selection of ties, form lumber, and form liners).
- Deflection permissible, if specified by the engineer.
- Length of time that forms and shoring must remain in place (cycle time).
- How reshoring is to be handled.
- Form removal.
- Weight of the concrete.
- Carpenter-laborer ratio.
- Cost and Overall project schedule and quantity of materials required to maintain schedule.