Can somebody tell me how many yards of concrete it will take for a 20x25 ft. floor, 4 inches thick?

Answer 1

OK Six yard is enough, and no 4 inches isn't over kill, you might get away with 4 inches if it's a patio but if you are going to use it as a driveway go with the re bar grid on 24 centers. I see that everyone does the math different ...even me I break in down into square inches then back to feet then yard and add 3% but I won't bore you with the math LOL I think he meant 6.9 yards not 69 but lets say seven just for fun ( six will do it) at $70.00 a yard you are still looking at under 5 dead presidents!!! For another 400 bucks and 2 thirty packs I bet you can find some sombreros to lay it for ya!! Good Luck

Answer 2

1 cubic yard (27 cubic feet), is a cube that is 36 inches per side, or 46656 cubic inches. This means that all three sides are the same. Say that one side is different, and the other two sides are the same (we'll call those 'y') with the one we'll call 'x'. So, we have x*y^2. Doesn't look like much, but if our 'x' is the 4 inches, and we know the total volume is the same then we can work with it. 4y^2 = 46656 cubic inches (volume) ==> y^2 = 11664 square inches (area) ==> y = 108 inches (linear measure) Note the way the dimensions change as we went along. So, apparently if you have a depth of 4 inches, you can cover a square area that is 108 inches (9 feet) per side.....an area of 81 square feet as some others have posted. To check this, take 4" x 108" x 108" I get 46656 (cubic inches), so it checks. :)

Answer 3

With no offense meant to you or any of the 9 I see who have answered, I have to ask, why not do the math yourself?

Consider the answer not in volume, but simple math.

Consider a "Yard" and squared, then consider envisioning that into 4 inch slabs 1 sq. yard each, then calculate the space you wish to fill, versus the measurements you've calculated in the concrete.

As one answer states (allow Overkill)

Each Cubic yard will give you approximately 9 squares, 36" x 36",,,4 inches thick.

Steven Wolf
(The Rev.)

Answer 4

One yard is 3 feet, so 20ft is about 6.67 yards and 25ft is about 8.34 yards. Four inches is 1/3 of a foot which is 1/3 of a yard so 4 inches is 1/9 of a yard...now multiply it all out

6.67yd x 8.34yd x 1/9 yd = 6.17 cubic yards or as previous answerer indicated 6.2 yards...I would assume that you cannot order less than half yard quantities so the answer is 6.5 yards. If you can tolerate a bt of extra it would be wise to order 7 cubic yards to ensure you have enough. Good luck and dont forget the wire mesh or rebar.

Answer 5

7 yards is correct and leaves you a little play. 4" is plenty thick enough. Buy fiber re-inforced concrete for best strength. This way you won't need wire mesh reinforcing.

Make sure the area is well compacted and ground not frozen in any way (ideally on a bed of compacted sand about 3 to 6" thick or more).

Note: Concrete with fiber does not finish as nicely as regular concrete (only a little less) but is great for outdoor areas or any area being covered with lino, tile etc. indoors. Works well for a brushed finish.

Answer 6

Concrete will pour 81 square feet per cubic yard at 4" thickness; you have 500 square feet. You need 6-1/4 sq. yds. If your excavation is a little irregular you might want another 1/4 yard for a safety margin.

Residential floors are typically 4" thick; that part is fine.

I'm a custom builder, Im not guessing.

Answer 7

My gosh there are some idiots here aren't there. But my answer is the right one.
25 x 20 = 500 sq. ft.
depth 4 in. which is 1/3 of a foot
500 divide by 3 is say 170 cubic feet
170 cubic feet divide by 27 =6 1/2 cubic yards.
You should use metal mesh reinforcement. Good luck. Not so hard.

Answer 8

you will need 69 cubic yard of concrete to for this slab also be aware a slabe of this size should be at least 6" thick and have 1/2" rebar reinforcements placed in a lateral grid patern of no less than 24" to prevent the slab from cracking and breaking. if you decide to listen to this advise you will need 102 cubic yards when
********when figuring on how much concrete you will need get the number of cubic yards (length x width x depth) the add 3% more to compensate for shrinkage*****

Answer 9

about 7 yards, If your going 4 inch thick, it must be because your going to have an exceptional amount of weight on it, If its a patio or simialiar, the 4 inch is overkill, good luck. Do yourself a favor for something that sixe and rent a powertrowel.

Answer 10

1 cubic yard is 27 cubic feet of cement.

In your case, you have 20 * 25 * 1/3 = 167 cubic feet.

or... 6.2 cubic yards

But 4 inches thick sounds too thin. I'm thinking you will get major breakup soon.