When can I remove the forms on cement?
When can you remove the forms from concrete? It depends on the job requirements or specifications. Slip forms, moving forms, and unformed concrete don’t have forms holding the concrete at all after it is placed, it stands up by itself and holds its shape because the concrete is placed in very stiff condition. Once the concrete is finished, the concrete is cured by covering with plastic, wet burlap, or a concrete curing compound to keep it from drying too quickly, taking away water needed for hydration.
Forms used for slab edges can usually be removed the same day or the following day, as long as the edges are protected from spalling, usually by backfilling with clean, damp earth.
Beam and column forms are often left in place seven days to allow them to cure, shoring underneath, and bottom forms are left until the strength reaches a minimum of 75% of design strength, or the total strength required by the specifications, depending on the engineer’s requirements.
You can use “high-early” (fast setting) concrete if forms need to be removed more quickly, if you have an approved high early design mix, but this is usually more expensive than ordinary concrete.