QA

Question: How To Figure Concrete Footings

How to calculate concrete: Determine how thick you want the concrete. Measure the length and width that you’d like to cover. Multiply the length by the width to determine square footage. Convert the thickness from inches to feet. Multiply the thickness in feet by the square footage to determine cubic feet.

How do you calculate footings?

How to Calculate Footing Size Determine the width and length of the cement slab in inches. Divide the width by 12 to convert it to feet. Divide the length by 12 to convert it to feet. Determine the depth or thickness that is required for the footing in inches. Multiply the width by the length and then by the depth.

How do you calculate concrete footings?

How to Calculate Concrete for a Footing-Continuous Spread Footing. First you need to convert all of your measurements to feet. Do this by dividing the width and depth by 12”. 24” / 12” = 2′ and 16” / 12 = 1.33′.

How do I calculate my foundation?

Find the cubic feet of your foundation walls by taking the total number of feet in length, which is 100 feet long in the above example, and multiply that number by the foundation wall height, which we will call three feet, for a total of 300 feet.

How do you figure yards of concrete for a footer?

How do I calculate how much concrete I need for a slab? Measure the area in feet. Multiply length by width, and then by thickness. Divide the resulting number by 27 to find cubic yards.

How many yards of concrete do I need for a 24×24 slab?

For example, for a concrete slab that is 24′ X 24′ X 4”, simply enter 4 in the Thickness/Depth field, 24 in the Width field, and 24 in the Length field. Click “Calculate”. Your answer should be 7.11 yards. Note: The Concrete Volume Calculator can also be used to determine yardage for aggregate products.

How deep should a concrete footing be?

Depth of Footings Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.

How thick should a footer be?

A concrete footer can be anywhere from 20 to 30 inches wide and 8 to 10 inches thick. You’ll see them 10-inches thick more often than not. The foundation wall is usually 8 inches wide.

How is foundation depth calculated?

Depth of foundation formula:- as per Rankine’s theory & formula minimum depth of foundation is represented by formula = p/w (1-sin Φ /1+sin Φ) 2, where p=gross bearing capacity, w =density of soil, Φ =angle of response of soil. But in practice, the foundation depth is kept at 0.90m or even more.

How many square feet is a yard of concrete 4 inches thick?

One Cubic Yard of Concrete: 4-inches thick – covers 81 square feet.

How many yards of concrete do I need for a 10×10 slab?

The amount you will need for a 10 x 10 slab is 1.3 cubic yards, we always add an extra 10% to allow for any slab depth variations or spills that may occur.

How much concrete do I need for a post hole?

A: Finding the right amount of concrete depends on the size of the hole and the size of the post. The diameter of the hole should equal about three times the diameter of the post and the depth of the hole should be about ⅓ to ½ the total length of the pole.

How much does it cost to pour a 24×24 slab of concrete?

A typical 24×24 garage slab costs between $3,057 and $5,944 with prices ranging from $5.31 to $8.31 per square foot for a 4” reinforced slab of concrete, and $6.83 to $10.32 per square foot for a 6” slab of reinforced concrete.

How thick should a concrete slab be?

Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.

How many bags of concrete do I need for a 10×10 slab 4 inches thick?

The thickness of your 10′ x 10′ slab will determine just how many bags you need. The average thickness of a 10′ x 10′ concrete slab for a shed is 4 inches thick. At 4″ thick, your 10 x 10 slab will take 56 bags of concrete that weigh 80 lbs.

How deep should footings be for a 3 foot wall?

The general rule of thumb is to bury about one-eighth of the height of the wall. For example, if your wall will be three feet (36 inches) tall, the first course of blocks should start five inches below soil level. The gravel base should start three inches below this.

What size footing do I need?

You can look up the recommended footing size, based on the size and type of house and the bearing capacity of the soil. As you can see, heavy houses on weak soil need footings 2 feet wide or more. But the lightest buildings on the strongest soil require footings as narrow as 7 or 8 inches.

Can I use quikrete for a footer?

Quikrete cement is designed for a do-it-yourself project. It can be used to complete a variety of concrete construction projects, such as pouring footings.

Do I need rebar in my footers?

Do You Need Rebar in Concrete Footings? Including rebar in a concrete footing means that you can reduce the risk of the concrete being pushed and pulled apart – cracking – from ground force pressures. Knowing this, it is generally a good idea to use rebar in footings for any structure.

How deep must a foundation be?

The minimum depth of the strip foundation trench must be at least 400mm below the original ground level. The average minimum thickness of the foundation must be at least 200mm. The strength of the concrete used for unreinforced strip footing must be at least 15MPa or better.