The term stucco screed can refer to several different items used in the application of stucco to a structure but usually refers to a weep screed. This type of screed is a metal form installed at the base of a stucco wall and serves to limit the buildup of moisture within a building. Another type of screed is a channel screed, which is used to shape and form stucco as it is applied to a structure. It serves both to control the depth of the stucco application and to allow the stucco to be shaped and formed for ornamental purposes. A simpler type of stucco screed provides a depth gauge for a stucco wall.
Stucco was originally used on solid brick walls that were usually several bricks thick. These thick walls did not have problems with moisture buildup under normal circumstances because they served as their own moisture barriers. Even now, stucco on solid brick walls will not normally need a stucco screed for drainage purposes. Wooden frame structures, however, typically do require a weep screed, as moisture can seep into the wall through the porous stucco or from the interior spaces of the structure.
A stucco screed, typically one with small holes to allow drainage, is installed along the bottom of wooden-framed structures to allow any moisture in the walls to escape. This type of stucco screed is mounted at or above the level of the foundation plate and maintains a small space through which moisture can escape. A weep screed is required by most building codes and should be installed 4 or more inches (10.16 cm or more) above the exterior grade to avoid being clogged with dirt.
Different types of stucco screeds are used in the installation of stucco above the foundation line. As with all plaster, the depth of the coat is important in stucco installation. A stucco screed that is attached to the framed wall can serve to maintain constant coat depth by providing a point of reference when the stucco is being applied and by separating different areas of the wall surface material. In more elaborate stucco work, areas of different color and texture are combined on a single wall. A channel stucco screed, which has two parallel flanges to form an edge for stucco with spacing between, is often used to space these two different areas of stucco evenly.