How do you figure the cost of a 40X72 foundation? Dh use to work in concrete before his computer training, so he and his buddies can form it and pour it their selves. I need to know how to figure the cost of this. Anybody know? Thanks, Cindyc.

That is too vague. Type of foundation? Height of walls? Slab? Crawl space? etc.! Basement walls in this area(8 foot tall) range from 80-100.00 a running foot installed. Concrete is 90-100 a cubic yard. It also depends on corners, concrete mix etc. Jill

ROFLMBO It'll depend on the local cost of concrete and what specific mix of concrete you get, and how thick you want the slab (and those will be determined by it's intended use).

yea, that is what he said after I posted this... I just didn't want to wait for the answer. He's working on an outdoor project, and I am figuring a building cost. Two different projects in two different places. I suppose I can wait if nobody here knows. But I figured if somebody does know, I wouldn't have to. Knowing all of the ingenuity on this board, I figured somebody had to know. Edited for spelling- not my strength.

Much more information is needed to give an answer. What kind of rebar is being used, What is the depth, What kind of vapor barrier is to be used. Then all you do is to Multiply the withxhight x length and get the cuibit yards you need then multiply it by the cost of concrete, add tax and wahalia you have the price.

Well, this will be a concrete slab for a house. We are using a 40X72X12 pole barn as a frame for a strawbale infill house. Roof will have 2' overhang all the way around. No crawlspace. Walls are 12 feet. No basement. Just your basic rectangle slab. Just your basic floor slab mix. Anything else you need to know?

LOL well you going to have to ask him how hes going to build it any way ! What mix what size and amounts of rebar who he likes to get supplies from what style foundation hes going to build depth of slab,where hes going to get forms etc. what he can cage off his buddies etc!

We need 3/8 to half inch rebar around the perimeter two rows. The slab will just have wire mesh in it. 18 inch wide fooder 12 inches deep, plus a 4 inch slab with 4 inches of gravel under it.

He makes his forms from recycled wood. He will get the supplies very likely from a friend of ours who owns a concrete company (his old boss) if he will travel far enough out of the area he normally works in. I think I have answered the other questions already. Thanks for the help. Cindyc.

I am not sure what kind of vapor barrier he plans to use, so he may not have decided yet. I guess I can still figure a ball park now besides that based on the information you have provided. Thanks. Cindy

We did a 4" slab for a barn last summer. 44 x 40. Concrete, flat work, mesh, fiber about 5500.00 All excavation and gravel extra. No plumbing or perimeter walls. Thickened edges.

Well for starters I would assume that you would need a footing upon which to place the foundation. You convert your figures into cubic yards to determine the concrete mix cost. A cubic yard equals 36 X 36 X 36 = 46656 cubic inches if figuring in inches which is easy with calculators, or 3 X 3 X 3 = 27 cubic feet to a cubic yard. The footing is kind of like a shelf you build upon, it distributes the weight over a wider area. You would have 224 feet of footing multiplied by 12 inches equals 2,688 multiplied by the thickness of the footer such as 8 inches, also multiplied by the width of the footer such as 18 inches. Thus 2,688 X 12 X 18 =580608 divided by 46656 (cubic inches in a cubic yard of material) equals 12.4 yards of concrete plus some for unevenness of the trench. In my area concrete flat goods currently is $72 a cubic yard meaning 13 X $72 = $936 for the concrete alone. To figure the foundation which will go on top of the footer you multiply the figures for the width and height of the desired foundation. Since I don't know your frost area and depth required to alleviate frost heaving I can't help you further. As was pointed out however you will need to figure in the reinforcing material in the footing, foundation, and slab. For the slab figure cubic inches into cubic yards or whichever you prefer. For a floating slab design you may not need a footing and foundation. Again, check with your other half and see what is needed where you live.

Multiply the length (in feet) by width (in feet) by the thickness (in inches) and divide by 314. I'm sure you have to know alot of other things also but that is from the internet. Hope it helps

Ours was completely contracted out. A trench was opened 6 foot deep, and eight foot wide, the center of the trench followed a course of 40 by 60 foot rectangle. A 40 by 60 foot foundation was framed and poured with; a one foot wide X one foot tall footer; with four pieces of rebar in the footer; had four 'piers' in it one at each corner one foot X one foot with four 18 inch anchor bolts on top and four rebar running vertically; had four piers centered on opposing long walls also with anchor bolts and vertical rebar; The foundation was poured five foot tall; with horizontal rebar laid in courses every foot going up. Inside the foundation, the crawlspace was dug-out, 6 mil plastic was laid down and one foot of crushed rock was laid on top of the plastic sheeting. It cost me $10k

Hi. Just did another stinkin' slab myself. Prices are going up this month they said but they gave no reason why. :shrug: Was there another huricane or war I didn't hear about??? 42x72x4" is about 36 cubic yards for the slab. Add to that the footing 2' deep 1' wide and running the perimiter of your slab, you need about 17 more cubic yards . So about 53 cubic yards all together. Its $90 a cubic yard here in oklahoma so somewhere around $5000 for just the concrete. Rebar and remesh will set you back a little as well. Hope that gives you something to work with.