To determine the size of the footing, a simple formula is used:
Make sure to use the same units for the depth measurement as well. Once you have obtained these three dimensions, you can calculate the concrete volume required for the footing by multiplying them together (length × width × depth), or by using our concrete footing calculator.
If you'd rather do the math yourself, simply measure length, width and height in feet. Then multiply these dimensions together. Divide the resulting number by 27 to find the cubic yardage. Once you have your measurement in cubic yards, consult our True Cost Guide for concrete prices.
to measure the length, width, and thickness of the footing in metres. Then, multiply those measurements together to get the cubic metre volume of the beam. To calculate the amount of steel needed for the footing in kilograms, multiply the volume of concrete footing by 0.5% and the density of steel (7850 kg/m3 ).
Exploratory test pits. The only way to confirm the foundation detail is to physically check by digging exploratory test pits.
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).
The material cost for concrete slabs generally ranges between $4 and $8 per square foot, with labor costs factored in. For a typical 30×50 concrete slab that is 6 inches deep, the cost can come to around $9000, but this could differ based on multiple factors such as the location of your building, among others.
Cubic feet formula: Length * width * depth/thickness
For example, if your slab is 10' wide and 10' long with 1' of depth, the volume of your slab would be 100 cubic feet (10x10x1 =100).
The formula of volume of a cubic foot is given as V = l × b × h = lbh ft3 or cubic foot where "V", "l", "b" and "h" are volume of a cubic foot, length of the cube (in ft), breadth of the cube (in ft) and height of the cube (in ft).
It can be calculated by dividing the foundation load by the contact area between the foundation and the soil. For example, if a strip foundation has a width of 1 m and a length of 10 m, the contact area is 10 m2. If the foundation load per unit length is 170 kN/m, the foundation stress is 17 kPa.
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).
A general rule of thumb is on cubic yard of concrete will cover the following areas: 4″ thick – covers 81 square feet. 5″ thick – covers 65 square feet. 6″ thick – covers 54 square feet.
1 part cement. 2 parts sand. 4 parts stone (aggregate by volume)
How much does a 40x60 concrete slab cost? An installed 40x60 concrete slab (4 inches thick) for buildings will typically cost between $9,600 and $19,200. A 4-inch slab will usually cost between $4 and $8 per square foot (depending on your location) for materials and labor.
How much does a 30x50 shop cost? On average, installing a 30'x50' shop will cost around $49,500. This estimate covers several key components: the steel building kit package, priced at approximately $30,000; the concrete slab foundation, which typically costs $9,000; and the construction expenses, estimated at $10,500.
How much does a 30x40 concrete slab cost? The average cost is $4 to $8 per square foot. The median price is about $6 per square foot. Based on these averages, you may pay $4,800 to $9,600 with a median estimate of $7,200.
To determine the size of the footing, a simple formula is used: Structural Load (lbs) / Soil Capacity (psf) = Footing Surface Area Required (sq. ft.)
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).
The thickness of the footings should be not less than 200mm and is usually mass concrete only, ie. no reinforcement. The depth below ground level to the base of the footing should be not less than 300mm or to rock, whichever occurs first, which allows for a minimum of 100mm of ground cover to the pad.
Depth of Footings
Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings must also extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or be frost-protected.
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.