When constructing a new building, it is necessary to “stake” the structure, that is, marking the future corners on the ground. This may need to be done several times, depending on the condition of the site and the design of the proposed structure. Staking can be done by nearly anyone. It can be the landowner, the excavator, the contractor, the architect, or even a surveyor. The accuracy of this “staking” depends on the ability of the person doing the staking and the limits of their equipment. Surveyors are uniquely qualified to do this. Not only do they have the skills and equipment to ensure that the corners are exactly where they are desired, but they are also able to ensure that zoning or HOA requirements are being met.
Depending on how the property lays and what is being constructed, the structure may need to be staked multiple times. For example:
- To clear the lot
- To bench out the land for a walkout basement
- To dig the footers
- To lay blocks or construct forms for the actual foundation
(there may need to be repeat staking due to the loss of set points during construction)
The needed accuracy of these increases as you get closer to the final stakeout. A rough idea is all that is typically needed to clear trees. Being within a few feet is all that is needed to bench out the land. All that is needed for the footer is to be within a few inches. But pinning the footers for the block needs to be less than 0.02 feet (¼ inch) in accuracy.
There are a lot of ways to mark things for construction. Sometimes, the contractor will want offsets set. That is, marks online but away from the actual corner. This allows excavation without disturbing the monuments. It also adds the potential for error on the part of the excavator.
Another point to consider is what is being staked. We typically stake the block corners; the exact location where the foundation should be constructed. Sometimes, we are asked to stake the “brick ledge.” This is usually 3 ½ inches outside of the foundation. It is the footer where brick is placed when done as a veneer over the concrete foundation/walls.
Unless specifically requested, by default, we don’t stake piers for support points inside the foundation or piers for deck support outside the foundation. Over the years, we have found that it is a waste of clients’ money (the more points we stake, the more we have to charge – it’s a time thing) as these usually get dug last, and the points we stake get ripped out during the excavation of the actual footer.
Most excavators are more than capable of measuring the location of these after the walls are set (or the footers are poured). The “accuracy” of these is not as important as the footers are usually much larger than the post/column being put on them.
It’s also worth noting that foundations and walls, etc., are not always perfect, and these posts/columns need to be orientated to the “final” product and not the theoretical stakes we put in the ground.
In the end, someone must decide who is going to stake what. It is important to understand what exactly is being done and how accurate this will be.