What is described as a reference plane representing the average of the finished ground level?

The concept of a grade plane is used in the context of plumbing and building design to establish a standard reference point related to the site's topography. In building and plumbing codes, the grade plane is defined as an imaginary flat surface, typically reflecting the average finished ground level around a structure. This reference is crucial because it impacts several factors, including drainage, the placement of plumbing fixtures, and compliance with building codes that dictate minimum elevations for sewage and water lines to ensure proper functioning and avoid flood risk.

The grade plane helps in determining the height of buildings, flooring, and the required setbacks from property lines. By providing a consistent reference level, it ensures uniform application of regulations pertaining to construction and plumbing that relate to water flow and drainage systems. This reduces the potential for issues such as flooding or backflow in plumbing systems.

Understanding the grade plane aids professionals in appropriately designing systems that comply with Kentucky's plumbing codes, ensuring safety and functionality in installations.