According to standard productivity norms, what is the expected out-turn (area completed) for a 2.5 cm thick cement concrete floor per mason per day?

Introduction / Context:
Out-turn (productivity) norms help in planning labour, estimating durations, and preparing cost estimates. For thin cement concrete floor toppings such as 2.5 cm thickness, productivity depends on mixing, placing, compacting, finishing, and curing practices.

Given Data / Assumptions:

• Thickness of floor topping = 2.5 cm cement concrete (site-mixed or ready-mix as per specification).
• One mason working with appropriate helpers in a typical day.
• Standard site conditions without unusual constraints.

Concept / Approach:
Schedules of Rates and practical handbooks provide indicative out-turns for common items. Thin C.C. floor toppings require careful finishing and surface accuracy, limiting daily area. A typical benchmark widely used in exams and preliminary planning is about 5.0 sq.m per mason per day for 2.5 cm thickness.

Step-by-Step Solution:
Identify the item and thickness: 2.5 cm C.C. floor.Consult standard norms: thin topping with finishing generally allows moderate coverage.Adopt the indicative value: ≈ 5.0 sq.m per mason per day.Select the option matching this norm.

Verification / Alternative check:
Cross-checking with other sources shows ranges; however, 5.0 sq.m is the commonly accepted exam key figure balancing finishing quality with productivity.

Why Other Options Are Wrong:

• 2.5 sq.m: Unduly conservative for standard conditions.
• 7.5 sq.m or 10 sq.m: Aggressive for quality floor finish at 2.5 cm thickness.
• 12.5 sq.m: Unrealistically high for consistent finishing.

Common Pitfalls:
Ignoring curing and finishing time in productivity; extrapolating from thicker slabs or machine-finished floors without adjustment.

Final Answer:
5.0 sq.m