When planning to restore a home, many questions haunt the mind. What are the ways to clean the roof of your house? Which trendy decor theme should you choose to modernize the interior? Otherwise, how to dress and protect the walls?
📋 The essentials at a glance: Personally, I believe that meticulous preparation of the surface determines the success of your surface finish by more than 90%. My opinion is categorical: trying to hide active cracks without applying reinforcing mesh exposes the wall to new openings very quickly. It is enough to methodically cross the smoothing passes with a wide knife to obtain a perfectly flat surface ready to paint.
Steps to properly plaster a wall
- Prepare the surface: clean, dust off, and repair cracks or holes.
- Apply a bonding primer (if necessary) for better adhesion.
- Prepare the plaster: homogeneous mixture according to the manufacturer’s instructions.
- Spread the plaster: apply with a trowel or float, in thin and even layers.
- Smooth the surface: pass the trowel in crossed movements to even out.
- Let dry for the recommended time.
- Lightly sand to eliminate small roughness and obtain a smooth finish.
- Apply the finish: paint, wallpaper, or other decorative coating.
Although they do not seem as difficult as one might think, different steps must still be followed.
This article explains everything you need to understand in order to perfectly plaster a surface. But before addressing the heart of the matter, let’s first look at the roles of plaster.
🗣️ My experience: In March 2026, I supervised the renovation of a large corridor partition of 25 m² that had been roughly patched after the removal of an old wall cabinet. The craftsman on site wanted to apply a 4-millimeter thick smoothing plaster layer all at once to fill the hollows quickly. The real lesson I learned from this project is that this product shrinks and cracks if it exceeds the maximum recommended thickness of 1 millimeter per pass.
What is the purpose of applying plaster on walls?
| Step | Objective | Necessary tools |
|---|---|---|
| Wall preparation | Clean and healthy surface | Brush, cloth, filler plaster |
| Bonding primer | Improve adhesion | Roller or brush |
| Plaster preparation | Homogeneous mixture | Bucket, mixer |
| Plaster application | Cover and smooth the surface | Trowel, float |
| Smoothing | Even out the finish | Clean trowel |
| Drying and sanding | Obtain a perfect surface | Fine sandpaper |
| Finishing | Provide the desired decorative finish | Paint, wallpaper |
In renovation or during construction, plastering a wall is a crucial step not to be neglected. Since work is already expensive, there is nothing like having a building that is both stylish and in excellent condition.
Since the wall is the most visible part of the house, it is necessary to take care of it to ensure the aesthetics and durability of the structure.
To achieve this, wall plaster is highly recommended. It primarily allows you to hide and correct imperfections. It makes the surface uniform, which is pleasant to look at.
But that’s not all, the product adds a decorative touch to the wall. It serves to enhance its appearance. The plaster comes in many finishes, including scraped, troweled, raw, or crushed. There is something for every taste and budget. It rejuvenates the surface by giving it a new look.
Some premium models can waterproof the substrate. Thanks to them, it becomes less vulnerable to weather and humidity. Even better, their application helps improve the building’s thermal insulation.
💡 Practical tip
To detect the slightest relief defects before starting decorative painting, place a work lamp or a halogen spotlight with grazing light against the wall. The cast shadows will instantly reveal any material shortages.
How to plaster a wall so that it is perfectly smooth?
Whatever technique you use, it is strongly recommended to choose a high-quality plaster. Although it is often expensive, it offers a better finish, enhancing the final appearance of the wall.
When selecting the product, take into account the type of materials. Some models are suitable only for a particular substrate.
If you are unsure, it is better to opt for a multi-purpose plaster. This can treat several surfaces such as plaster, cement, concrete, brick, or plasterboard. It can be used both indoors and outdoors.
For the wall to be ultra-smooth after application, pay attention to its preparation. If it has roughness, it seems almost impossible to make it uniform without correction.
By the way, if your house has drywall walls, consider checking out our article titled: how to repair a hole in a plasterboard wall.
How to prepare a wall before plastering?
This preliminary phase contributes to the quality of the finish. Therefore, it must be done carefully. In any case, its execution is child’s play.
If you are wondering, for example, how to waterproof a terrace, this task requires in-depth technical knowledge.
Before preparing a wall, the major structural work must be fully completed. Also, you must finish insulation and electrical installation. The same goes for adjusting and installing partitions.
Once these tasks are completed, carry out a diagnosis of the substrate to be plastered. It must be not only clean but also hard, dry, healthy, and cohesive.
The wall sometimes shows peeling or flaking paint. Otherwise, it reveals rough spots. You must scrape and then brush the affected areas. Once done, proceed with sanding. In case of cracks, remember to fill them using a filler compound.
When grease accumulates over time, it leaves ugly stains. Dust can also dirty the surface. To get rid of them, do not hesitate to wash the surface.
If the latter is covered with mold stains, this indicates a moisture problem. It must be treated before starting the work. Otherwise, the quality of the filler will likely be affected.
Why doesn’t the filler stick to the wall?
This kind of issue generally occurs when you use a filler of poor quality. People often tend to choose it to save a few euros. However, the product peels off just after a few days.
This phenomenon also appears in case of poor surface preparation. Some people start applying the product immediately on a rough surface. It is therefore normal that it does not stick.
Otherwise, the problem comes from the type of surface. For example, on new concrete, micro-holes may exist even if they are sometimes invisible to the naked eye.
If you do not fill them during preparation, the filler cannot penetrate these hollows, which creates bubbles.
Similarly, the product does not adhere due to the impact of moisture. In fact, almost all construction-related defects are due to this problem. If you do not treat its origin, the freshly filled surface will likely lose its effect in a short time.
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🌍 Did you know?
Working in a room that is too hot, at a temperature above 25 degrees, artificially accelerates the drying of the filler on the surface, which prevents it from adhering properly to the wall and makes it very crumbly during sanding.
As mentioned above, you must start by preparing the surface. Once done, gather the necessary materials, namely the filler itself, filling knives, a spatula, a plastic trough, a painter’s knife, sandpaper, a step stool or ladder, and many others.
⚠️ Common mistake
Imperfectly cleaning your filling knives between sessions is a classic trap. Small pieces of dried plaster stuck on the edge of the steel blade will create systematic horizontal scratches on your wall during the next pass.
If you use powdered filler, first mix it with water according to the indicated proportions. Apply the product using a spatula in horizontal lines and on the upper parts.
Then gradually move downward and avoid going over already treated areas, otherwise you will damage the finish.
Once you cover all parts of the wall, let the filler dry for 24 hours. After this period, all that remains is to sand. If you notice imperfections, do not hesitate to correct them. Please discover this analysis on the use of powdered filler and ready-to-use paste filler:
🍀 Good sides
- Perfectly homogeneous texture without any mechanical lumps
- Unlimited usage time because the product does not set in the bucket
- Ideal for small smoothing surfaces and drywall joints
🔻 Limits
- Purchase cost per kilogram significantly higher than powder bags
- Slightly greater material shrinkage during drying on large hollows
To successfully plaster a wall, also get inspired by our tips for applying a smoothing plaster, discover the essential steps to repaint a ceiling, and explore our practical advice for filling a hole in a wall.
FAQ – Plastering a wall
How to plaster a wall cheaply?
If you already have the necessary equipment or tools, the application doesn’t cost you much. But if the wall to be plastered is in poor condition, you shouldn’t tighten the budget. The work turns out to be more complex.
How to plaster a wall quickly?
If you don’t have much time, it is better to entrust the job to a professional. With their experience, they will know how to do it faster.
Why plaster a wall that has holes?
The application of plaster must first be preceded by filling the holes. Once this step is done, you can expect an excellent finish.
