Explain in detail using sketch the centre line method of reducing quantities of earth work, DPC and R.C.C. in slab.

This method is suitable for walls of similar cross sections.
In the centre line method, the sum of all the centre line lengths of long walls and short walls are added to get the total centre line length.

Here the total centre line length is multiplied by breadth and depth of respective item to get the total quantity at a time.

When cross walls or partitions or verandah walls join with main wall, the centre line length gets reduced by half of breadth for each junction.

For each junction half breadth of the respective item or footing is to be deducted from the total centre length calculated.