What are Construction Elevations?
During my time as a licensed plumber I think one of the more neglected topics is Construction Plan Reading. Very little can happen on a construction site without competent tradesmen that are able to follow a For Construction set of drawings.
But before you can even start to get your bearings on a job site, the lead plumber must have a practical working knowledge of the definition of building elevations and how they relate to the plumbing trade. So elevations are numbers most often given in feet and inches and fractions of inches but sometimes given in decimals, used to relate the vertical and horizontal measurements or distances between certain points as they relate to all other points on the jobsite. These numbers will appear on the jobsite prints on the Plan Views, Elevations Drawings and Section Elevation drawings.
The jobsite elevation is usually related to some other elevation off the jobsite like sea level or a city municipal bench mark elevation. However sometimes they are specific to a jobsite benchmark only. In the case of a job specific elevation that elevation should only used to coordinate the vertical and horizontal measurements on that particular job.
Jobsite elevations are relative to each other in that you can always compare one to another. The higher elevation number is higher and the lower is the lower elevation. So you can compare multiple elevations in multiple locations regardless of the distance between them. Subtract the lower from the higher and you can tell instantly find out the vertical distance between points. This is extremely important to a plumber because it allows for him or her to relate the elevations of the different plumbing systems. For example it will allow the plumber to install the water and drainage system at the proper elevation, depth, pitch and height for all system to work in a defined space.
The vertical distance between to points can be established by finding the difference (subtracting) the two elevations.
**Example** Let’s say the elevation of of a basement floor is 90.00’ and you know the elevation of the first floor needs to be 100.00’ if you subtract the two you get 10.00’ or 10ft. So the measurement from the basement floor to the first floor is 10ft.
**Example** Here is a better example of how elevations can be important as they relate to plumbing. Lets say the invert elevation (inside bottom) of a sanitary sewer in a given street is 89.00’ and the basement floor is 80.00’, you will know immediately that the sewer is 9ft above the basement floor, which isn’t unusual however anything draining into the aforementioned basement would have to be pumped or lifted to a point higher the sewer in the street before it drains away.
We hope this clarifies the concept of Elevation measurements. Please fell free to comment or add any thoughts you may have regarding the piece.