Basics in Building Construction

Building Components And Types

Lesson 25 : Form Work

Form Work For Column Footings

Depending upon the shape of the column footing, form work of suitable shape is to be provided to receive the concrete. The usual shape is square or rectangular and is accompanied by vertical sides or sloping sides.

For a column footing with vertical sides, a box of required dimensions is prepared from planks and one side of the box is made about 30 cm longer than the other. Suitable braces are provided to make the box rigid and strong. For further security, the opposite sides may be connected by wire fixed on nails before concrete is placed in the form work. The wire will remain in the concrete when form work is removed.

For a column footing with steps, the bottom box is filled with concrete and after a short time, the top box is placed on the surface of the wet concrete and filled with concrete. In the similar way the form work for steps are built. For a column work with sloping sides, the bottom planks are of required vertical sides and after placing footing reinforcement, the box of side planks is placed on the bottom planks and both are suitably connected. Sometimes, concrete is placed up to the top of bottom planks before the box of side planks is placed in position.