- 2076 Chaitra · 2 marks
Multiplying factors: panelled and louver door
Short answer
Painting quantity equals opening area (width x height) times the factor per side. Panelled door uses 1.30 and louvered door uses 1.80, so a 1.0 x 2.1 m door gives 2.73 m2 and 3.78 m2 per side respectively.
Explain the multiplying factors adopted for panelled door and louver door.
Doors are painted over a larger surface than the plain opening area because of panels, mouldings and slats. To simplify measurement, the area of the door opening (including the frame) is multiplied by a factor.
| Door | Multiplying factor (IS 1200 Part 15, per side) | Reason |
|---|---|---|
| Panelled door | 1.30 | Recessed panels, mouldings and rails give about 30% extra surface |
| Louvered (venetian) door | 1.80 | Inclined slats are exposed on both faces and their edges; the surface is nearly double |
Use: painting quantity = width x height of the door opening x factor (for each painted side). For example, a panelled door of 1.0 x 2.1 m painted on one side = 2.1 x 1.30 = 2.73 m², and a louvered door of the same size = 2.1 x 1.80 = 3.78 m².
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