We’ve reached a crucial task in the progress of our new building: plastering. Plastering involves covering all internal walls and ceilings with mortar to protect surfaces and improve aesthetics. Once plastering is complete, the installations done in previous stages will no longer be visible. I consider this a pivotal task because, at this point, we have the opportunity to make changes to previous works without significant cost.
1. What should I do before starting the plastering process?
First, I need to check that all previous tasks are complete, are in the right places, and nothing has been forgotten. A good tip is to spend enough time at the construction site and photograph or videotape all areas, creating a complete record of all installations. This will be useful throughout the project, especially when you need to drill into the walls. It’s also a good idea to place a measuring tape next to the photos to have accurate dimensions of the electrical, plumbing, and HVAC passages.
It’s also very important to place mesh tape at the joints between bricks and concrete, as well as around electrical pipes, to prevent cracks
Image 1: Documenting electrical installations with the help of a measuring tape
Image 2: Mesh tape to prevent cracks and the first layer of plaster (scratch coat)
2. What are the plastering mortars?
Mortar, in general, is a mixture of building materials. Specifically, plastering includes three layers of mortar:
- Scratch coat: This is a mix of sand, lime, cement, and water in a very fluid form. It is “thrown” with a trowel onto all surfaces to be plastered, creating a rough surface on the walls so that the next layers of plaster adhere well.
- Base coat or brown coat: This is a mixture of sand, cement, and lime, usually sprayed onto the surfaces. It has a thickness of 2-6 cm to create flat surfaces.
- Finish coat: This final layer consists of white cement, lime, and marble dust. It is applied with a float and ensures a relatively smooth surface by filling in the small gaps left by the previous layer.
Image 3: Second stage of plastering (base coat or brown coat)
Image 4: Third stage of plastering (finish coat)
3. Does the weather affect when I should do the plastering?
Extreme weather conditions generally affect construction work, especially in the initial stages. For plastering, we want each layer to be completely dry before applying the next. Warm weather is ideal. If we choose to do the work during the winter months, we must allow longer intervals between layers to ensure the proper result. If we plaster during a heatwave, we need to moisten the mortar so it doesn’t dry too quickly and crack.
4. What are the most common mistakes during the plastering process and how can I avoid them?
One of the most common mistakes is inadequate surface preparation, which can lead to the plaster detaching. Also, applying plaster in very wet or very dry conditions can cause problems with the final result. To avoid these mistakes, it’s important to strictly follow preparation instructions and consider weather conditions.
5. I have seen some metal corners used during plastering. What are they?
Metal corners, also known as corner beads or plaster stops, are very important materials used during the plastering process. These are angular profiles, usually made of galvanized steel, placed on wall corners before applying plaster.
Two main benefits of corner beads:
- Protection and reinforcement of corners: Metal corners provide reinforced protection to wall corners from bumps and wear. Without them, corners would be more vulnerable to damage during everyday use of the building.
- Creating straight corners: They ensure that the corners will be perfectly straight and precise. This is important for the aesthetic of the final result and for the ease of installing decorative elements or furniture that may require precise corners
Image 5: Plastering corner beads
Extra tip:
Pay special attention to plastering bathrooms. In bathrooms, we need completely flat and vertical surfaces to later install tiles without problems.
The next stage is installing marble sills and insulation. Read the next blog on 12/07/2024.
The above are not technical texts and aim to simply inform the reader. The MECHA Engineering team has experienced engineers who will guide you accurately and scientifically through your technical project needs.