Construction Layout / Setting out
Construction layout includes the layout of buildings, curbs, storm and sewer drainage system and other site features. This could also include staking of building corners, staking the location and elevation of a new sewer line and staking the location and elevation of any type of concrete to be poured (roads, driveways, etc.)
Construction surveying is the translation of construction plans into physical points on the ground that can be used as a basis for the actual construction. The results of construction surveying are seen in most urban, suburban or rural setting. Almost any roadway, building, or other man-made improvement likely had some amount of construction surveying involved. Construction surveying provides not only the horizontal location of new improvements, but also the vertical information required to ensure that surfaces drain or pipes flow as required.
The stakes and points set during the process of construction surveying are not usually set at the actual construction point, but typically on some sort of offset. This is done so that the survey stake is not disturbed by excavation or other activities that will take place at the actual point of construction. The stakes are marked with an “offset” and a “grade.” The “offset” is the distance from the survey stake to the horizontal position of the actual point of construction, and are typically three feet for curb and gutter or ten feet for underground pipes. The distance of the offset should be coordinated with the contractor to accommodate any specific needs due to existing field conditions or special equipment, and should be clearly marked on the survey stake. The “grade” represents the change in elevation that needs to be obtained from the reference point to the actual construction point, which is expressed as a “cut” (lower in elevation) or a “fill” (higher in elevation). The grade should also indicate the vertical feature that the grade is referencing, usually a flow line or finished floor elevation.
That is to say that, the surveyor is involved from start to finish on a construction project.