When it comes to beautifying our walls and ceilings, we often apply a thin layer of mortar known as plaster. This not only makes the surface smoother but also allows for decorative finishes. In this article, we’ll explore how to determine the amount of materials needed for plastering.
Important Points to Consider
- Cement Density: Cement weighs around 1440 kg per cubic meter.
- Sand Density: Sand typically ranges from 1450 to 1500 kg per cubic meter.
- Aggregate Density: Aggregates vary from 1450 to 1550 kg per cubic meter.
- Cement Bag Weight: One bag of cement is usually 50 kg.
- Volume of Cement Bag: The volume of one cement bag is approximately 0.03472 cubic meters or 1.226 cubic feet.
- Number of Cement Bags: You’ll find approximately 28.8 bags of cement in one cubic meter.
- Cubic Feet in One Cubic Meter: 1 cubic meter equals 35.31 cubic feet.
Calculating Material Quantity for 12 mm Thick Plaster
To calculate the material needed for a 12 mm thick plaster with a 1:6 (1 Cement:6 Sand) ratio on a 100 sqm wall, follow these steps:
- Volume of Mortar: Multiply the area by the thickness to find the initial volume, which is 1.2 cubic meters.
- Wet Volume of Mortar: Add 30% for joints and unevenness, making it 1.56 cubic meters.
- Total Dry Volume: Increase by 25% to get 2 cubic meters.
Now, let’s find the quantity of each material:
- Cement Quantity: (2 / (1 + 6)) * 1 = 0.30 cubic meters or 432 kg (at a density of 1440 kg/m³).
- Sand Quantity: (2 / (1 + 6)) * 6 = 1.80 cubic meters or 63.558 cubic feet.
- Water Required: 432 kg of cement * 0.5 (water-cement ratio) = 216 liters.
Alternatively, you can calculate sand quantity using bags of cement:
- Sand Quantity: 8.64 bags * 6 (sand ratio) * 1.226 (volume of one bag of cement) = 63.55 cubic feet.
You can use similar methods for other plastering ratios.
Material for 20 mm Thick Plaster
For a 20 mm thick plaster on a 100 sqm wall, consider 20% mortar for joints and unevenness:
- Wet Mortar Quantity: 100 * 0.02 + 20% = 2.4 cubic meters.
- Dry Mortar Volume: After a 25% increase, it’s 3.00 cubic meters.
Calculate material quantities as previously explained.
Rich Mortar Plastering
Rich mortar plastering requires less material as cement fills sand voids. Calculate accordingly.
Ceiling Plastering 12 mm Thick
For RCC ceiling plastering, use 20% extra mortar for evenness:
- Wet Mortar Quantity: 100 * 0.12 + 20% = 2.6 cubic meters.
- Dry Mortar Volume: After a 25% increase, it’s 1.80 cubic meters.
Calculate material quantities as discussed earlier.
6 mm Thick Plastering in RCC
For a 6 mm thick plaster on RCC, consider 1.00 cubic meter of dry mortar.
These calculations help ensure you have the right materials for your plastering project, whether it’s for walls, ceilings, or specific thicknesses.
