Building Construction Multiple Choice Questions & Answers (MCQs) on “Types of Plaster Finishes”.
1. The mortar used for the smooth cast finish has cement and sand in the ratio of ___________
a) 1:2
b) 2:3
c) 1:3
d) 1:4
Answer: c
Clarification: The mortar used for the smooth cast finish has cement and sand in the ratio of 1:3. A smooth and levelled surface is obtained in this finish.
2. In sand faced finish, the second coat of plaster is applied after curing the first coat for __________ days.
a) 7
b) 15
c) 21
d) 27
Answer: a
Clarification: Sand faced finish is acquired by plastering in two coats. The second coat of plaster is applied after curing the first coat for 7 days. The surface of the final coat is finished by rubbing clean sand of uniform size.
3. In smooth cast finish, steel floats are not recommended for external renderings.
a) True
b) False
Answer: a
Clarification: In smooth cast finish, steel floats are not recommended for external renderings. Instead, a wooden float is used for applying the mortar. This is because steel floats give a very smooth finish which is very likely to crack when exposed to atmospheric conditions.
4. The first coat in sand faced finish is applied in ___________ cement sand mortar.
a) 1:2
b) 1:3
c) 1:1
d) 1:4
Answer: d
Clarification: The first coat in sand faced finish is applied in 1:4 cement sand mortar. However, the mortar for the second coat has cement and sand in the ratio 1:1. The first coat is provided with zigzag lines.
5. In sand faced finish, the thickness of the second coat is ___________
a) 4 mm
b) 8 mm
c) 12 mm
d) 15 mm
Answer: b
Clarification: In sand faced finish, the thickness of the first coat is 12 mm while the thickness of the second coat is 8 mm. The sand in the mortar mix for the second coat should be perfectly screened in order to obtain a uniform size resulting in the surface having sand grains of uniform density.
6. Rough cast finish is also known as ____________
a) Dry dash finish
b) Pebble dash
c) Spatter dash finish
d) Textured finish
Answer: c
Clarification: Rough cast finish is also known as spatter dash finish. This type of finish is waterproof and durable. It is also resistant to cracking and crazing.
7. 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
Answer: a
Clarification: 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.
8. Which of the following types of plaster finishes is used with stucco plastering?
a) Smooth cast finish
b) Pebble dash
c) Scrapped finish
d) Textured finish
Answer: d
Clarification: Textured finish is used with stucco plastering. In this, suitable tools are used to make ornamental patterns on the final coat of stucco plastering.
9. Pebble dash is also known as ___________
a) Dry dash finish
b) Rough cast finish
c) Wet dash finish
d) Spatter dash finish
Answer: a
Clarification: Pebble dash is also known as dry dash finish. The mortar used in this type of finish has cement and sand in the ratio 1:3. It is applied in a thickness of 12 mm.
10. In pebble dash, the size of pebbles used generally varies from ___________
a) 2-5 mm
b) 10-20 mm
c) 20-35 mm
d) 30-50 mm
Answer: b
Clarification: In pebble dash, the size of pebbles used generally varies from 10-20 mm. These pebbles are dashed against the surface in order to keep them in position. The pebbles may also be lightly pressed in the mortar by using a wooden float.