Math problem for crete guys?

[woolybear]

For anyone that knows anything about concrete work.

Little project I have planned here shortly.

I have 110 sq. ft. of area I need to cover with 3"- 4" of concrete. I know there's a formula to figure this, but for the life of me I can't remember it.

I'll get it in either 60# or 80# bags(whatevers in stock). Just trying to get an estimate of how many bags I'll need to complete the job?

[92xj]

4" thick will be:

1.36 cubic yards

122.4 40# bags

81.6 60# bags

61.2 80# bags

I calculated a 10'x11'x4" area...fyi

[woolybear]

Hmmm....lots of mixing. Just a walkway with average weight foot traffic. Hand tamping and 4" gravel base I'm thinking maybe going with 2" of crete. Think that would be sufficient?

[92xj]

I dont know, everything I have seen and done is 4", also 95% of google says 4" as well, but did see some folks reference 2" thick.

[joeaveragehunter]

If you get frost, two inches will crack and heave the first year.

[redkneck]

I dont think I'd go less than 3. Wouldn't hurt if you could put some wire in it too, but really depends on your soil I think. There's places here in the red clay hills you could just about do it with 1", of course the ground rarely freezes too here.

[woolybear]

I suppose if I'm gonna do this, I may as well do it right and only once. Thanks guys.

[Jeramie]

Fyi, the formula is as follows....

LxWxD divide by 27

(Length x Width x Depth) Do all of this in feet. Keep in mind that 4" deep is 0.33333'. Divide by 27 which is how many cubic feet are in a yard of concrete (3x3x3=27).

If you have a concrete mixer you can always use portland which covers about 15sqft per bag at 4' deep (you have to mix with parts of sand and gravel). However, if it were me I would just order a couple yards from the concrete company. It is about $78 a yard here right now and that would be the cheapest and easiest way to go.

[brad dryden]

Call a cement company we did I think it was a 10'x10'x4 for the hot tube and was cheaper to have them come out and pour it then what we could by buying bags.

[redkneck]

We have a 3 yard minimum around here for delivery unless you pay an extra fee.

[brad dryden]

Here this may help you out.

http://www.concretenetwork.com/concrete/howmuch/calculator.htm

[doubleA]

Been there and done that once...never again. I even get the bagged concrete mix for nothing. When you figure in time getting it, travel, labor loading/unloading , mixing etc it's just not worth it for a job that size IMHO.

In my area, there are a couple of companies that have trucks that will mix the amount you need right on the spot. Our pool was done with shotcrete in this manner. They are used alot for sidewalks and such when large amounts are not needed.

Here is an example...http://www.custom-crete.com/index.htm

Like the others, I would look at running wire cloth and 3-4" thickness and include expansion joints.

[stevebeilgard]

go with premix only. too expensive to go the bag way.

suggestion: set your 2 x 4 forms. call a contractor and tell him next time he has a pour to do, add your work for time & materials only. you'll wind up with a professional job pretty cheap. or, call the cement company and tell them next pour they have short of a full load, you need the extra concrete.

[mike]

Hmmm....lots of mixing. Just a walkway with average weight foot traffic. Hand tamping and 4" gravel base I'm thinking maybe going with 2" of crete. Think that would be sufficient?

Steve is right in with letting a contractor know that you have a small pour to do when they have time, might save them the small load charge doing yours at the same time. Another thought is if it is just a walk way you can get patio blocks at your local home store fairly cheap. some as low as a buck a square foot and for walkways i think they look better