Pile Column Footings are constructed with typical pile depths between 13'-26' (4-8 m), pad depths of 21”-36” (53-91 cm), and pile spacings of 2'6”-4' (76-122 cm). Pad widths are commonly between 6'-11' (1.83-3.35 m) with column sizes of 8”-16” (20-41 cm).
A guideline for the depth is 12 inches, plus one additional inch for every three inches of the column. For example, the footing for a six-inch column should be at least 14 inches deep.
Spread Column Footings are constructed with typical footing heights between 8”-24” (20-61 cm) and footing widths of 24”-96” (61-244 cm). Spread Column Footings are commonly paired with column widths of 8”-24” (20-61 cm).
The minimum depth of footings below the surface of undisturbed soil, compacted fill material or controlled low strength material (CLSM) shall be 12 inches (305 mm). Where applicable, the requirements of CBC Section 1809.5 shall also be satisfied. The minimum width of footings shall be 12 inches (305 mm).
Footings are proportioned to have equal soil pressure under each column to minimize differential settlement. Practical dimensions for footings are a minimum depth of 1.5 times the width, widths of 1000-3000mm, and reinforcement spacing of 150-200mm.
Footing thickness - 8 to 12 inches. Footing depth - varies based on frost line and soil strength (some footings can be shallow, while other must be deep)
Spacing Between Vertical Bars: The spacing between vertical rebars is typically based on structural requirements, but it usually falls between 4 and 12 inches. Proper spacing is necessary to avoid concrete congestion, which can lead to uneven concrete flow during pouring.
A minimum of 12”inches deep for all footings and the width will be determined by the amount of stories, 12” inches for a single story, 15” inches for a two story and 23” inches for a three story. This is based on a soil bearing capacity of 1500(psf).
Footings need to be 600mm wide x 1m deep minimum,in some cases depending on ground quality/type,proximity of large trees footings are required to be up to 2m deep.
Isolated footing is another common type of footing. It is used to support individual columns or isolated loads. Isolated footing is often used in conjunction with continuous wall footing to provide additional support. Combined footing is used when two or more columns are close together and need to be supported.
The footing depth, on the other hand, is typically determined by the soil type and the extent to which you must dig before striking undisturbed soil. Still, we recommend that the depth of the footing extends to a minimum of 12 inches after you've hit undisturbed soil.
The effective depth is determined from the cross-section's geometry as 𝑑 = ℎ − 𝑐 − ⌀𝑠𝑤 − Τ ⌀𝑠 2, where ℎ is the height of the cross-section, 𝑐 is the concrete cover, ⌀𝑠𝑤 is the diameter of the stirrups, ⌀𝑠 is the diameter of the longitudinal reinforcement.
The minimum depth of footing on sandy soil is 0.8 - 1 m, for rocky soil, it is 0.05 - 0.5 m and for clayey soil, it is 0.9 - 1.6 m. The minimum depth of foundation for the load-bearing wall is 900 mm.
Meanwhile, when constructing columns, piers or walls, a rebar of 8mm or greater must be used, and for foundations and building footings, a rebar of at least 10mm in diameter is the best choice to minimise settling.
To determine the size of the footing, a simple formula is used: Structural Load (lbs) / Soil Capacity (psf) = Footing Surface Area Required (sq. ft.)
First off: Why you need accurate footings calculations
If you make your foundations too shallow or too deep, there is a risk to the integrity of the build, and a danger that any reinforcement, be it mesh panels or rebar rods, is positioned incorrectly, leading to reduced tensile strength and load-bearing capacity.
Each deck support post must be supported by concrete footings. The size of each footing is determined by the tributary load imposed on it. See the diagram below for an explanation of tributary load. Footing must be dug down into undisturbed soil and to a minimum depth of 12-in below the finished grade.
For every 2 feet of adjustment to the width of the house, add or subtract 2 inches of footing width and 1 inch of footing thickness (but not less than 6 inches thick).
Stronger. Compared to carbon steel, fiber-reinforced polymer rebar can be as much as 4.5 times stronger. For construction, this equates to less material requirements per square yard of concrete than conventional steel rebar.
Rebar is a good choice for projects that will experience a lot of wear and tear, such as industrial lots, underground parking lots, or other commercial parking lots. Wire mesh is a better option for light to medium traffic areas like driveways and sidewalks.
A 4"-thick concrete driveway for vehicles or ½-ton trucks does not need hot-rolled steel to last for decades. Thicker concrete, driveways with poor ground support, and driveways that often sustain heavy loads or vehicles should be strengthened. What is rebar?