What is PCC and why is it done before footing? | Q & A

1. Leveling Does Not Require Reinforcement

• The purpose of leveling concrete is to:

  • Provide a flat, uniform base

  • Act as a separation layer between soil and footing

• It does not carry structural loads

Reinforcement is required only when tensile stresses are expected, which is not the case here.

2. PCC Is More Economical

• Reinforcement steel is expensive

• Using RCC for leveling would:

  • Increase cost unnecessarily

  • Increase construction time

PCC achieves the purpose at much lower cost.

3. Simpler & Faster Execution

• PCC:

  • No steel fixing

  • No bar bending

  • No cover blocks

• Faster to place and level on site

4. RCC Needs Proper Design & Cover

• RCC requires:

  • Proper structural design

  • Accurate cover to reinforcement

• At soil level, maintaining correct cover is difficult and impractical

5. Durability Consideration

• Steel in RCC near soil is exposed to:

  • Moisture

  • Chemicals

• Risk of corrosion without any structural benefit

6. Structural Logic (Key Interview Point)

Reinforcement is provided to resist tension, not for leveling.

Since leveling concrete:

• Works in compression only

• Carries negligible stress

PCC is sufficient.

One-Line Interview Answer (Perfect)

PCC is used for leveling because it is non-structural, economical, easy to execute, and reinforcement is not required for leveling purposes.

Common Follow-Up Question

Q: Can RCC ever be used below footing?
A: Only if it is specifically designed as a structural element, not for leveling.