According to standard productivity norms, what is the expected out-turn for 12 mm thick cement plastering per mason per day (under normal site conditions)?

Introduction / Context:
Out-turn norms guide planning of manpower and project durations. For plastering, productivity depends on surface preparation, mixing, application, finishing, and curing. Standard references provide indicative daily areas per mason for commonly used thicknesses like 12 mm.

Given Data / Assumptions:

• Plaster thickness = 12 mm cement mortar.
• One mason with usual helper support.
• Normal, unobstructed site conditions without unusual detailing.

Concept / Approach:
For 12 mm plaster, a widely accepted benchmark is about 8.0 sq.m per mason per day. Thicker coats, awkward geometry, or multiple coats reduce output; mechanized mixing or ideal conditions may increase it slightly, but 8.0 sq.m is a robust planning value and common exam standard.

Step-by-Step Solution:
Identify task: uniform 12 mm plaster over prepared masonry.Consult typical SOR/handbook norms for daily output.Select the closest benchmark value: 8.0 sq.m per mason per day.

Verification / Alternative check:
Cross-referencing multiple handbooks shows 6–10 sq.m as a typical range; 8.0 sq.m is the central figure used for planning and examinations.

Why Other Options Are Wrong:

• 2.5, 4.0, 6.0 sq.m: Understate typical productivity for 12 mm plaster.
• 10 sq.m: Optimistic for consistent finish quality under normal conditions.

Common Pitfalls:
Ignoring time for corner beads, scaffolding moves, or curing; extrapolating from thinner coats or machine-sprayed systems.

Final Answer:
8.0 sq.m