How much concrete would it take to fill a hole 12 inch dia x 12 inch deep?

Question

I am putting in 16 footings for benches at a Regional Park and need to buy the right amount of concrete (quikcrete). This is for an Eagle project and I want to buy the concrete in 60lb bags at Home Depot. I won't have extra money so I don't wnat to buy more than I need. I would appreciate any ones opinion. Thanks! (PS -my moms avatar)

Answer 1

To figure out the volume of a cylinder, you use the following:

V=pi*R^2*h

V=3.14*6"*6"*12"

V=1356 cu. in./1728

V=.7847 cu ft. per hole * 16

V= 12.55 cu ft total

A 60 lb bag of Quikrete is about 1/2 cu. ft.  That means you will need 26 bags.  I'd get 28, just to be sure i had enough.  You can always return unused bags.  Good luck with your project!

Answer 2

Go read the bag!

Go read the round duct stuff - it says right on it.

Answer 3

Yes, it is 26 [25.6] bags given your measurements.

However, 12 in. dia per footing is pretty big considering that it is  a footing for a park bench and not a deck or a fence. You could cut that down to a 10 inch diameter and reduce your purchase to  22 bags [save $10]

Answer 4

if the holes are circular then i guess you are using some kind of auger ...just dig them yourself square ..save the cost of the auger ..and a 12 inch auger is a two persons machine ..you could save double ...PS   sorry to hear your moms got avatar ...hope she gets better !..PPS what is avatar?

Answer 5

Its about .78 cu ft per hole minus the displacement of what you are anchoring. I would use the 1 bag per hole rule its very close using 60lb bags.....