Procedure
- Excavate the pit of desired size.
- Ram the bed of footing adequately.
- Pour a bed of PCC of 6″/150mm height with 1:4:8 mix. Make level of PCC perfectly horizontal.
- Lower the reinforcement cage at the bottom.
- Place column cage vertically and tie to bottom cage.
- Splash sides of trench with cement mortar up to 1 feet i.e. upto height of pedestal, so that soil does not fall on pedestal.
- Clean bed of PCC of all foreign matter and wet with water before pouring concrete for pedestal.
- Fabricate box frame for pedestal.
- Pour concrete of at least M20 grade in pedestal formwork.
- Compact concrete using mechanical vibrator.
- For trapezoidal footing, sloped portion starts at column outside ring and ends at pedestal edge.
- Use stiffer concrete for trapezoidal portion to avoid sliding down of concrete.
- Care should be taken to compact concrete in sloped portion.
- Use stepped foundation for better results and more compact foundation.