Distempers are generally used to coat ..........
Understanding Distemper
Distemper is a traditional, water-based paint. Its main components are chalk (or whiting), pigments for color, and a weak binder like animal glue or casein, all mixed with water. It's known for being an economical and breathable coating, but its properties limit where it can be effectively used.
📝 Detailed Analysis of the Options
(a) Compound wall & (b) External concrete surfaces
Suitability: Highly Unsuitable.
Reason: Distemper has very poor resistance to weather. The weak binder (glue) is water-soluble. When exposed to rain, it will soften and wash away. Sunlight will cause it to become brittle and chalky. Therefore, it cannot be used on any exterior surface that is exposed to the elements.
(c) Interior surface which are not exposed to environment
Suitability: Ideal.
Reason: This is the correct answer. Distemper is perfectly suited for interior walls and ceilings in dry areas. Its main advantages here are its low cost and high porosity (breathability), which allows moisture vapor to pass through the wall, preventing trapped moisture. Since these surfaces are protected from rain and direct sun, the distemper's lack of durability is not an issue.
(d) Wood works
Suitability: Unsuitable.
Reason: Wood expands and contracts with changes in humidity. Distemper dries to a hard, brittle film that is not flexible. This lack of flexibility means it would crack and flake off as the wood moves. Furthermore, it offers very little protection to the wood from moisture or wear. Wood requires a more durable and flexible coating like an enamel paint or varnish.
📊 Suitability of Distemper for Various Surfaces
| Surface | Suitable? | Reason |
|---|---|---|
| Interior Walls (Dry) | Yes (Ideal) | Economical, breathable, protected from weather. |
| Exterior Walls | No | Not weather-resistant; will wash away. |
| Kitchen/Bathroom Walls | No | Not resistant to moisture, steam, or washing. |
| Woodwork | No | Too brittle; will crack with wood movement. |