What is the length of stakes used when installing formwork for a 4-inch thick concrete slab?

When installing formwork for a 4-inch thick concrete slab, the stakes used serve to hold the form in place, preventing it from moving or bowing out under the weight and pressure of the wet concrete. The general practice for stake length in formwork is that stakes should be driven into the ground to provide sufficient support while also extending above the top of the form.

A stake length of 1 foot is often adequate because it provides enough height to hold the form securely above the ground while still allowing for a stable anchor to the soil, ensuring that the form remains in position when the concrete is poured. This length allows the stake to be driven deep enough into firm ground for stability, while not protruding excessively above the formwork height, which can be cumbersome and can interfere with the pour.

Longer stakes, like those extending to 2 feet or more, may not be necessary for a slab that is only 4 inches thick, and could lead to decreased efficiency during the installation process. Thus, a 1-foot length strikes a balance between stability and practicality for this application.