COLUMN FOOTING ESTIMATE

COLUMN FOOTING ESTIMATE

Column is the essential part of building. We provide column as a structural vertical member which transmit load into soil. 

I often see in field that people are confused how much materials they buy for casting column for there building. Sometimes they buy more than the materials required. So excess materials cause wastage of money. And sometimes they buy less than the required materials then a problem occurred when they cast column.

Here I give you the details overview how to calculate the materials. First we need to know the terms of column footing.
1. BASE :- Lower most rectangular or square part of column.
2. TRAPEZOIDAL PORTION :-   Its a trapezium like parts which connects column to base.
3. COLUMN  :-  Part of column which is out of the earth.

Lets Assume Base 4ft x 4ft Column 10 inch x 10 inch 

1. First of all We cut earth as per base dimension in a certain depth.
Let base dimension is 4 ft x 4 ft and the depth is also 4 ft .
So Volume of Earth Cutting is   -  4 ft (Length) x 4 ft (Breadth) x 4 ft (Height) = 64 cft.

2. Next 3" sand filling is required
So volume of Sand is -  4 ft (Length) x 4 ft (Breadth) x 3 in / 0.25 ft (Height) = 4 cft.

3. Then Single Layer Brick Flat Soling provided.
So Brick Soling for 4 ft (Length) x 4 ft (Breadth) = 16 sft.
3 bricks required for 1 sft soling. Then for 16 sft we need 16 x 3 = 48 nos of Brick.

4. Now 5 inch thick Plane Cement Concrete provided over entire Brick Flat Soling.
 So, Concrete Volume is 4 ft (Length) x 4 ft (Breadth) x 5 in / 0.42 ft (Height) = 6.72 cft.

5. From here Reinforced Concrete Starts. Calculation For strip abcd.
 Volume of Concrete is  4 ft (Length) x 4 ft (Breadth) x  8 in / 0.66 ft (Height) = 10.56 cft.

6. Now trapezoidal section come. For strip cdef
Volume of Concrete formula is - (ef +dc)/2 x L X h
So Volume is (10 inch /0.83 ft + 4ft)/2 x 4 ft x 1 ft = 9.66 cft

7. Now the Column part is left upto GL (Ground level). Strip efgh.
 Volume of Concrete is  10 inch/ 0.83 ft (Length) x 10 inch/ 0.83 ft (Breadth) x  17 inch / 1.41 ft (Height) = 0.971 cft.

So Total Concrete Volume is (6.72 cft. + 10.56 cft. + 9.66 cft + 0.971 cft.) = 27.911 cft

Consider Mixing Ratio is 1 : 1.5 : 3
For 1 cft concrete Stone chips required  = 0.86 cft
                               Sand required             = 0.43 cft
                               Cement required          =0.24 bag

So here for 27.911 cft   Stone chips required  = 0.86 x 27.91 = 24 cft
                                      Sand required             = 0.43 cft x 27.91 = 12 cft
                                      Cement required        =0.24 bag x 27.91 = 6.69 say 7 bag

So For a column casting (base 4' x 4' - column 10" x 10") the materials required is

Fine Sand = 4 cft
Medium Sand = 12 cft 
Stone Chips =24 cft
Bricks = 48 no
Cement = 7 bag.

Conclusion :- Here I give the clear view how column estimate prepared . Now follow this method anyone can prepare estimate of his own building column footing. Hope you enjoy this if any doubt comment me below and if this article help a little bit please shear it and thus support me. Thanks