How to dig footings for a building
A concrete footing is the part of a building's foundation that supports the weight of the building. The term "footing" is used in the building and construction industry to refer to the hole which is dug to measurable specifications.
Footing also refers to the concrete structure which is framed and poured into the footing excavation. The first step in creating the finished element of the foundation called the footing is excavating the proper size and shape hole which is, confusingly, also called the footing.
Obtain the specifications for the footing from a building's blueprints. The building's prints will detail the size, depth and shape required for the building's footings. The plans will include elevations, cross sections and notes, which detail every aspect of the footing excavation.
Layout the footing using measuring equipment. Use surveying equipment for larger excavations. A simple tape measure and heavy string will suffice for smaller buildings and additions. Mark the boundaries of the excavation with surveyor's flags
Contact local municipal offices which oversee construction in your region of the country if you are digging a footing for a building addition or remodel project that does not include blueprints. Specifications for footings vary by geographic region. The type and height of the building also affects the footing requirements.
Excavate a trench for the footing with the backhoe, or excavation equipment. Footings are not normally dug by hand, since they extend more than 4 feet under the grade level, and can be many feet wide. Dig a trench 1-to-1-1/2 feet wider than the footing specification to give the contractors room to build the wood concrete forms in the bottom of the trenches.
Dig the last 6 inches of the depth by hand using a square nose shovel. Building code specifies that the concrete footing must rest on undisturbed ground. Excavation equipment cannot cleanly dig a footing to meet these building requirements.