What is the primary function of a grade stake in construction?

The primary function of a grade stake in construction is to indicate future ground level. Grade stakes are typically used during the excavation and grading phases of a construction project to provide a precise reference point for where the finished ground level will be. This ensures that the site is leveled accurately according to the design specifications. By establishing the intended grade, workers can accurately plan their excavation or fill operations to achieve the desired elevation, which is crucial for proper drainage and overall site performance.

The other options, while related to construction practices, do not specifically align with the primary purpose of grade stakes. For instance, marking utilities is essential for safety and planning, but it is not the primary function of a grade stake. Similarly, providing a waterproof barrier and measuring slope are important tasks in construction, yet they are not directly associated with the role of grade stakes, which are more focused on marking elevation levels.