1. Thumb rules for
Presented by: PRANAY KUMAR TODE
For an idea
2. Ofcourse, RCC columns have to be designed in
accordance to the total load on the columns but
apart from that it is essential for every Architect to
remember a few thumb rules so that they are
prevented from making mistakes while deciding
the approximate place for columns.
Three thumb rules to be followed are as follows:
-Size of the Columns
-Distance between Columns
-Alignment of columns
3. Thumb rule no.1
Size of the columns
The size of the columns depends on the total load on the
Minimum size of the column should not be less than 9”x9”.
9”x9” columns are to be used for a single storey structure
with M15 grade of concrete.
In case, 9”x9” column size is to be used for 1 and half
storey structure, then it is advised to use M20 grade
A safe and structurally sound column size for a 1 and half
storey structure should not be less than 12”x9” using M15
grade concrete. This should be in your most preferred and
practical options list.
4. Thumb rule no.2
Distance between the columns
Try to maintain equal distance between the centres of two
columns. Always plan a column layout on a grid.
The distance between two columns of size 9”x9” should not be
more than 4m centre to centre of column.
If larger barrier free distances are required then going for
larger column size is to be used.
The size of the columns increase because of two factors:
Increase in the distance between two columns (This increases
the dimensions of the columns as well the depth of the beam.)
Height of the building (Increase in the number of floors is
directly proportional to the dimensions of the columns.
5. Thumb rule no.3
Alignment of Columns
A rectangular grid is to be made for placing the columns. This
helps in avoiding mistakes and placing in columns can be
done in the right way.
The columns can preferably be arranged in two different
In a straight line with the help of a grid
In a circular fashion for circular buildings.
Zigzag arrangement of columns is an absolutely wrong way of
working out Structural design. It should be remembered that
when columns are erected, beams are laid connecting the
6. The Zigzag column placement causes three major
-Unbalanced load transfer
-Problems in wall construction
-Problems in laying beams
If these three thumb rules are followed by
Architecture students, implementation of wrong
Structural design can be prevented.