What function does a "screed" serve in concrete work?

A screed serves the critical function of leveling and smoothing the surface of fresh concrete. When placed on top of freshly poured concrete, the screed is typically moved back and forth or pulled across the surface to ensure that the concrete is evenly distributed and reaches the desired elevation. This process is essential for achieving a flat and uniform surface, which is important for both the structural integrity of the concrete and for any finishing work that may be done later, such as placing tiles or applying coatings.

By creating an even surface, the screed minimizes issues like uneven settling and ensures that the capillary action within the concrete is uniform, which can have implications for curing later on. While screeds can also play a role in determining the final finish of the concrete, their primary purpose is to establish a smooth and level base before any decorative elements or additional curing processes take place.