Question

In rough cast finish, the mortar for the final coat has the ratio ____________ (cement: sand: aggregate).

(a) 1 : 3/2 : 3

(b) 3/2 : 1 : 3

(c) 1 : 3/2 : 4

(d) 1 : 1/2 : 3

The question was posed to me in an interview for job.

The origin of the question is Types of Plaster Finishes topic in division Pointing and Plastering of Construction & Building Materials

Answer 1

Right answer is (a) 1 : 3/2 : 3

Explanation: In rough cast finish, the mortar for the final coat has the ratio 1 : 3/2 : 3 (cement : sand : aggregate). Here, the size of the coarse aggregate varies from 3mm to 12 mm. A large trowel is used to dash the mortar against the prepared plastered surface.