pre-mix concrete bag

[harley dahnke]

How much surface 4" thick will a 60# bag of pre-mix concrete cover?

[Robert Fogt]

According to Reade, portland cement weighs 94 pounds/cubic foot

60 pounds / 94 pounds/cubic foot = 0.6383 cubic foot

Now we have the volume and the thickness, so we can calculate the area. First have to convert 4 inches to feet.

0.6383 cubic foot / (4 inches / 12) foot = 1.9149 square feet

It will cover about 2 square feet that is 4 inches thick. Assuming a density of 94 pounds/cubic foot

[Unregistered]

How much surface 4" thick will a 60# bag of pre-mix concrete cover?
I have an area 5'x4' 4' thick how many bags of concrete 40 lb do I need.

[Robert Fogt]

Try this calculator here:
http://www.decks.com/calculators/concrete.aspx

Though it only lists how many 60 pound or 80 pound bags you need. But you can take the 80 pound bag number and divide by 2.

[Unregistered]

I believe they are talking about "bags" of pre mixed conrete which come in 60 # bags as opposed to "sacks" of portand cement which weigh more.

[Unregistered]

How much surface 4" thick will a 60# bag of pre-mix concrete cover?

The Instructions on the pre mix concrete bags say a #60lb bag will do 1 square foot, 4"thick.

[Unregistered]

The information was great thanks

[Unregistered]

How much surface 4" thick will a 80# bag of pre-mix concrete cover?

[Unregistered]

How much surface 4" thick will a 60# bag of pre-mix concrete cover?
how many bags will be need to complete a 20' X 3'6"x4"

[Unregistered]

how many bags of 80# ready mix I need for a 9'x9'x2"thick area?

[A guy]

Look up a few posts to the calculator link. Just use the Square Footing to calculate whether it's 6"x12"x4" or 30'x20'x4". Although as you get into the really big areas your error will increase, because the amount of water you use in your mix will likely vary from what they used to get their data.

[Unregistered]

how many bags of 60# or 80# do i need for an area of 13'x9'. 4" thick?

[JohnS]

how many bags of 60# or 80# do i need for an area of 13'x9'. 4" thick?
4" = 1/3 ft, so you need 39 ft³
An 80 lb bag yields 0.6 ft³, so 65 bags.

[Ready Mix]

how many bags of 60# ready mix concrete would i be needing if i want 5'x5' area that is 2" thick? I'm new to this, and have read a quick guide on what portland concrete is on a concrete guide, but I still do not know much about the quantities I should be using. thanks!

____________________________________

larry

[JohnS]

how many bags of 60# ready mix concrete would i be needing if i want 5'x5' area that is 2" thick? I'm new to this, and have read a quick guide on what portland concrete is on a concrete guide, but I still do not know much about the quantities I should be using. thanks!

____________________________________

larry
2" = 2/12 ft
5' x5' x (2/12) ft x 1 bag/0.6 ft³ = 6.94 bags (use 7)
assuming 80 lb bag yields 0.6 ft³

[Dirtman]

how many bags of 60# ready mix concrete would i be needing if i want 5'x5' area that is 2" thick? I'm new to this, and have read a quick guide on what portland concrete is on a concrete guide, but I still do not know much about the quantities I should be using. thanks!

____________________________________

larry

John's correct for an 80 lb bag of Sacrete.

Approximate yield for a 60 lb bag of Sacrete is 0.45 ft3. 4.17 ft3/0.45 ft3 = 9.26 bags (10 minimum).

Approximate yield for a 40 lb bag of Sacrete is 0.30 ft3. 4.17 ft3/0.30 ft3 = 13.89 bags (14 minimum).

I don't know what you'll be placing on this small slab but chances are 2" inches of concrete is going to crack. The minimum thickness should be 3" IMHO.

[Jason Patterson]

In general, if a 60# bag can cover 1 square foot 4 inches deep, then the following will work to determine the number of bags you need:

Step 1:
Figure out the volume of concrete you need in cubic feet. Use feet for units in all numbers.

Volume = Length x Width x Depth x Number of Objects
(For rectangular pads of uniform thickness)

Volume = 3.14 x Radius x Radius x Depth
(For round pads of uniform thickness)

Ex: I want to pour two 4'x10'x9" slabs. What is the volume?
V = 4 x 10 x (9/12) x 2 = 60 cubic feet

Step 2:
Figure out how many bags that is based on the bag size you want. Since a 60# bag can fill 1/3 cu ft, it takes 180# to fill 1 cu ft.

Number of Bags = Volume x 180 / (Bag Size)

Ex: Continuing on, if I wanted to use 40# bags for my slabs, how many would I need?
N = 60 x 180 / 40 = 270 bags

[Unregistered]

how many bags will be need to complete a 20' X 3'6"x4"

how many bags needed

[Dirtman]

how many bags will be needed to complete a 20' X 3'6" x 4"

20 ft * 3.5 ft * 0.333 ft = 23.31 ft3.

Assuming 80 lb bags of Sacrete at 0.6 ft3/bag: 23.31 / 0.6 = 14 bags (mininum)

[Unregistered]

How much surface 4" thick will a 60# bag of pre-mix concrete cover?
How much surface 4 inches thick will a 60# bag of premix concrete cover?

[Dirtman]

How much surface 4 inches thick will a 60# bag of premix concrete cover?

0.45 ft3/bag / 0.333 ft = 1.351 ft2 approximately

[Brittany]

How many pounds of concrete will i need for 61050 square feet?

[Unregistered]

According to Reade, portland cement weighs 94 pounds/cubic foot

60 pounds / 94 pounds/cubic foot = 0.6383 cubic foot

Now we have the volume and the thickness, so we can calculate the area. First have to convert 4 inches to feet.

0.6383 cubic foot / (4 inches / 12) foot = 1.9149 square feet

It will cover about 2 square feet that is 4 inches thick. Assuming a density of 94 pounds/cubic foot

I have to erect 8 10ft x 4in x 4oin wooden posts they will be in about 2ft in the ground,how many bags of conrete cement do i require?

[Dirtman]

I have to erect 8 10ft x 4in x 4oin wooden posts they will be in about 2ft in the ground,how many bags of conrete cement do i require?

I assume you're asking about bags of pre-mixed concrete (just add water). The number of bags depend on a couple items you haven’t addressed: 1) size of bag and 2) the diameter of the proposed post-holes.

The volume of the hole minus the displacement volume of the post needs to be calculated. For the volume of the hole, the formula is: Diameter2 * (PI/4) * depth. For the displacement volume of the post: length * width * depth. Using inches and assuming the post-hole will have a mean diameter of 10":

(10in * 10in * (PI/4) * 24in) - (4in * 4in * 24") = 1500.956 in3 each.

Pre-mixed concrete bag volumes are in ft3 (cubic feet), so convert in3 to ft3. 1500.956 in3 / 1728 in3/ft3 = 0.868609 ft3 per post * 8 posts = 6.9489 ft3 total

80 lb bag of pre-mix yields 0.6 ft3/bag. 6.9489 ft3 / 0.6 ft3/bag = 11.58, so 12 bags
60 lb bag of pre-mix yields 0.45 ft3/bag. 6.9489 ft3 / 0.45 ft3/bag = 15.44, so 16 bags
40 lb bag of pre-mix yields 0.3 ft3/bag. 6.9489 ft3 / 0.3 ft3/bag = 23.16, so 24 bags

Unless you use an auger, the diameter of the holes will vary, so always buy a few more bags than you believe you’ll need. The top of concrete should be above ground level and mounded slightly around the post, to shed water away from the wood.