A mortar made from gypsum plaster with certain impurities present or added during the calcining process, sand or wood fibre, and water for plastering interior surfaces.
The house’s interior and exterior walls are both plastered with cement plaster. To do a good job, you’ll need the best cement plastering available. Water, fine aggregates, and Portland cement are mixed to make cement plaster. To make cement plaster, different amounts of cement and sand are combined. There are three different types of cement grades to pick from. In the market, there is Ordinary Portland Cement (OPC), Portland Slag Cement (PSC), and Portland Pozzolana Cement (PPC). There are two grades of OPC: 43 and 53. Plastering work is best done with both grades.
This is the crucial distinction. Exteriors are normally coated with cement render, while interiors are usually completed with plaster. The coat of plaster is particularly smooth when applied to a level surface, making it ideal for interior surfaces. For added strength, cement rendering uses a significantly higher proportion of sand.
How to find the Cement Plastering Ratio?
Plastering is the process of covering a wall or ceiling with a layer of plaster (Cement plaster). Plastering is used to smooth out surface irregularities generated by brickwork and prepare the surface for painting. There are a variety of plastering materials available, but cement plaster is the most common.
Calculating the Cement and Sand quantities needed for plastering:
Points to keep in mind while calculating plastering job:
● The plastering ratios are volumetric cement and sand ratios (for example, Cement: Sand = 1:5, which is 1 component cement and 5 parts sand in a mortar)
● Plastering should be at least 20mm thick overall, with two coatings
The dry density volume of cement is 1440 kilograms per cubic meter
Each cement bag weighs 50 kilograms (110 pounds)
Each cement bag weighs 50 kilograms (1440 kg) and has a volume of 0.0348 cubic meters
Sand’s dry density is 1600 kilograms per cubic meter
● The plastering is done in two layers (two coats): the first coat is termed a Rough coat or Primary coat, and it is applied with a thickness of at least 12mm (typically between 12-15mm)
● The second coat, known as the Finish coat or Secondary coat of plastering, should be applied with an 8mm thickness
The second coat, known as the Finish coat or Secondary coat of plastering, should be applied with an 8mm thickness:-
● 1:6 and 1:5 This proportion is commonly used for internal brick plastering
● Ceilings and external walls are 1:4 scale
● 1:3 It is utilized where external walls are exposed to harsh environmental conditions since it is a rich mortar mix. It’s also utilized for the maintenance
The steps for calculating plastering quantities are as follows:
● The formula for Calculating the Area of Plastering:-
Area = Width x Height = 10 x 10 = 100m2
● The formula for Finding the Volume of Plastering:-
The First Coat Volume = Area of Plastering x Thickness of Plastering
● The volume of Second Coat = Plastering Area x Plastering Thickness
Calculating the amount of water needed for plastering:-
The amount of water to be added to the mix is determined by the moisture content of cement, sand, and the surrounding environment. Water is equal to 20% of the total dry material (Cement+Sand)
10 Cement Plastering Tools:-
3. Spackle Knife
5. Utility Knife
6. Paddle Mixer
7. Bucket Trowel
10. Paint Brush
Check This Out: What is the initial and final setting time of cement?