What is Rim

Definition of Rim in Construction

The rim is the top of a manhole, catch basin, or other assembly that has been installed in the ground, and is normally used for storm water collection or sanitary purposes. There are other assemblies that are used in the industrial and manufacturing industry that may incorporate the use of the term rim. Basically the rim is the top element of an assembly and its elevation is identified on the sitework documents with a distinct elevation. The rim elevation is a very common and important elevation on a project, and will be coordinated by the engineer to ensure that the proper rim elevations are both engineered to provide positive pitch, as well as properly located to maximize function. The rim elevations are coordinated with the surrounding grade elevations, as well as the corresponding pipes and other elements of the storm or sanitary systems, on a construction project by the sitework engineer.