Wall plastering is an essential part of a building's finishing process. The primary purpose of plastering is to create a smooth, even, and sturdy wall surface, ready for paint or other finishes. The most crucial aspect of this process is understanding the correct wall plaster mix.
A good plaster mix will prevent cracks, and damage as well as reduce the risk of water seepage. To help you get better results, let's delve deeper into the wall plaster mix and how to apply it below!
Understanding Wall Plastering
Wall plastering is a crucial stage in smoothing and beautifying house walls. This process involves coating rough brick walls with a mixture of cement, sand, and water to create a smooth and even surface.
The goal is to produce a smooth and even surface to help with the painting process. This step follows after brick installation. Keep in mind that you shouldn’t do the plastering work carelessly. It requires precision and proper techniques to achieve optimal results.
The Right Wall Plaster Mix
Making the right wall plaster mix is a critical step in the construction or renovation process. The correct mix will produce a strong, durable plaster with good adhesion to the wall surface.
Generally, a wall plaster mix is made with specific ratios of cement and sand. Here are the common ratios used to calculate the proper wall plaster mix.
1. Plaster Mix with Six Parts Sand for 15 mm Thickness
SNI 2837-2008 has set standards for the required wall plaster mix for cement and sand with a thickness of 15 mm. To plaster 1 m², you need 4.42 kg of cement and 0.027 m³ of sand.
For example, if you have a wall 10 meters long and 5 meters high, the total area to be plastered is:
Wall area = Length x Height = 10 m x 5 m = 50 m²
One sack typically contains around 50 kg of cement. Therefore, the cement and sand you need for plastering the entire wall are as follows:
Cement: 4.42 kg/m² x 50 m² = 221 kg or about 5 sacks of cement (221/50)
Sand: 0.027 m³/m² x 50 m² = 1.35 m³
So, you need about 5 sacks of cement and 1.35 m³ of sand to plaster a 50 m² wall with a 15 mm thickness and a 1 cement: 6 sand mix.
Read also: 5 Tips to Make Cement Walls Last Longer
2. Plaster Mix with Five Parts Sand for 15 mm Thickness
Based on SNI 2837-2008, it requires 5.18 kg of cement and 0.026 m³ of sand per square meter to make a plaster mix with a thickness of 15 mm with a 1 cement: 5 sand ratio.
For example, if you have a wall 10 meters long and 5 meters high, the wall area is:
Wall area = Length x Height = 10 m x 5 m = 50 m²
As mentioned earlier, one sack contains 50 kg of cement. Therefore, the required volume of cement and sand is:
Cement: 5.18 kg/m² x 50 m² = 259 kg or about 6 sacks of cement (259/50)
Sand: 0.026 m³/m² x 50 m² = 1.3 m³
So, you need about 6 sacks of cement and 1.3 m³ of sand to plaster a 50 m² wall with a 15 mm thickness and a 1 cement: 5 sand mix.
3. Plaster Mix with Four Parts Sand for 15 mm Thickness
According to SNI 2837-2008, you need about 6.24 kg of cement and 0.024 m³ of sand per square meter to make a plaster mix with a thickness of 15 mm with a 1 cement: 4 sand ratio.
If your wall is 10 meters long and 5 meters high, the wall area is:
Wall area = Length x Height = 10 m x 5 m = 50 m²
With one sack of cement containing 50 kg, the required volume of cement and sand is:
Cement: 6.24 kg/m² x 50 m² = 312 kg or about 7 sacks of cement (312/50)
Sand: 0.024 m³/m² x 50 m² = 1.2 m³
So, you need about 7 sacks of cement and 1.2 m³ of sand to plaster a 50 m² wall with a 15 mm thickness and a 1 cement: 4 sand mix.
Read also: Proper Application of Cement Plaster on Walls
Tools and Materials for Making Wall Plaster
In making the wall plaster mix, you need several main materials such as cement and sand mixed with clean water. Make sure to choose the best quality materials for neat and durable results. Besides materials for wall plaster, here are the tools you need:
- Sieve: Used to filter sand and ensure it is free of stones and dirt.
- Bucket: Used to measure the mix and take water during the mixing process.
- Hoe: Helps mix cement and sand.
- Level: A tool to ensure the plaster surface is even.
- Trowel: Helps spread the applied plaster on the wall.
- Wooden straightedge: Used to smooth and level the plaster surface perfectly.
- Mixing spoon: Used to scoop and apply the plaster mix to the wall.
How to Apply Wall Plaster
Applying wall plaster is a crucial step in the building finishing process to get smooth and neat walls. This process not only enhances aesthetics but also protects walls from damage and weather influences. Here is a brief guide to applying wall plaster.
1. Ensure the Wall is Ready for Plastering
Before starting the wall plastering, ensure the brick or block wall frame is ready and upright according to plan. Also, make sure the wall is free of dirt that can affect the adhesion of the cement.
2. Choose the Right Time
Ensure the brick wall is completely dry before plastering which is ideally 2 weeks after brick installation. This is to avoid trapped water in the plaster, which can cause issues like damp walls or white powder.
Read also: 3 Factors that Can Lower the Quality of Cement Mix
3. Ensure the Correct Plaster Mix Ratio
The correct plaster mix ratio is based on the proportion of cement and sand. For dry areas, use a 1:5 ratio, and for wet areas, use 1:3. Too much cement can make the plaster more prone to cracking, while too little will make the plaster brittle and easy to peel off.
4. Ensure There is a Plaster Guide
The plaster guide serves as a reference for the plaster thickness to prevent the wall from being wavy or slanted. Typically, the guide is made every 1 meter using the same mix as the plaster to prevent color differences and cracks at the joints.
5. Ensure the Plaster is Not Too Thick or Thin
The ideal plaster thickness ranges between 10-15 mm, with 10 mm for lightweight bricks. Too thick plaster can cause the wall to crack and peel off, while too thin plaster will not create a smooth surface.
Functions of Wall Plaster
Wall plaster is also useful for protecting the walls from sunlight and rainwater damage, such as cracks or water seepage. Moreover, it also has several additional functions, such as:
- Strengthening the wall structure.
- Help with the painting.
- Covering damage on the wall surface.
- Making the wall surface neater, cleaner, and more appealing.
- Protecting walls from weather conditions like rain and heat.
That concludes the information about wall plaster mix and its proper procedures. As discussed, one key factor in achieving high-quality plaster lies in the use of the right materials, especially cement.
High-quality cement will build strong and durable plaster that adheres perfectly to the wall. Semen Merah Putih offers various high-quality cement options, such as Portland Composite Cement (PCC), which could be your excellent choice.
Portland Composite Cement (PCC) from Semen Merah Putih is formulated with environmentally friendly technology and produced with a strict quality control system. This results in strong, durable, and eco-friendly cement, making it ideal for your wall plastering needs.
So, what are you waiting for? Get high-quality cement for your wall plastering needs by contacting Semen Merah Putih now!
Read also: How to Make a Simple Cement Leveling Tool
