How to prepare a wall for various types of decorative plaster

Applying a base coat and calling it a day is not enough to prepare a wall for decorative plaster. Careful preparation is required before beginning the process to guarantee that the plaster will adhere correctly and provide the desired finish. A properly prepared surface is essential whether you’re going to use Venetian, textured, or any other kind of decorative plaster.

The method used for wall preparation may vary depending on the type of decorative plaster. The best technique depends on a number of factors, including the type of plaster being used, its composition, and the state of the wall. Making the effort to thoroughly prepare the wall will pay off in the end by providing a smooth, durable finish.

Why is preparation for decorative plaster so important?

Even so, decorative coatings like concrete-look plaster often mimic the appearance of rough walls. Even with these types of coatings, surface preparation is a crucial step in repair operations.

If ignored, this will have an impact on how long the plaster lasts:

• Base with a porous structure has high moisture absorption (wood, foam concrete, aerated concrete, etc.).d.). They have the property of “pulling” moisture from the solution. Such substrates require careful priming after preparation.
• Smooth bases are characterized by poor adhesion to the decorative mortar, which will lead to its premature peeling.
• Decorative plaster does not adhere to the remains of wallpaper or whitewash. Such an error can lead to cracks and premature peeling.

Defects may have an impact on the coating’s longevity and appearance.

Decorative plaster: main stages of surface preparation

After doors and windows have been installed, flooring has been laid, and construction waste has been cleared from the property, the last phase of renovation is finishing with decorative plaster. The material is all-purpose; it works well on brick, concrete, wood, and occasionally even metal surfaces. It has a margin of safety, resists moisture and frost, lets the walls "breathe," and is not easily damaged by impact.

Painting preparation and surface preparation are very similar. Every task can be broken down into five phases:

1. Removing the old coating. Cleaning from paint, tiles or wallpaper.
2. Remove sockets and switches and insulate the wires
3. Securing the reinforcing mesh and applying a cement-sand mixture. The first helps to mask cracks, and the second – to seal them.
4. Elimination of defects. Prevents the formation of cracks.
5. Applying a primer. Necessary to improve adhesion.
6. Puttying. Helps to level the surface before the final stage of repair.

It takes a lot of time and effort to prep walls for decorative plaster, especially when doing it by hand. The standard algorithm mentioned above will vary slightly depending on the coatings used.

A flawless decorative plaster finish requires careful wall preparation. This include polishing the surface, caulking any fissures or blemishes, and making sure the wall is level and smooth. You can lay the perfect foundation for the plaster by doing these steps, which will help it adhere correctly and have the best possible appearance.

Features of preparation before applying Venetian plasters

Venetian finishing is a unique style of interior design that mimics priceless materials. It has particles of granite, quartz, marble, and polymer binder. In contrast to other kinds of decorative solutions, it appears opulent and rich but requires more "scrupulous" preparation.

The substance may have a small relief (approximately 1 mm deep) or be smooth. Since it is applied to perfectly flat surfaces, the same painting algorithm must be used to prepare them:

• Remove dirt, remove unnecessary wallpaper, remove tiles, whitewash.
• Align the base with beacons, achieving an ideal state.
• Sand the base carefully and thoroughly.
• Align it with putty.
• Sand each square centimeter manually. You cannot achieve perfect leveling using a tool.
• Apply a primer.

When grinding, make sure you have adequate lighting directed toward the wall. This will allow you to see every imperfection.

There are multiple layers to the material. If the base is not leveled beforehand, its elegance and beauty will not be fully appreciated.

It will be a lengthy and labor-intensive task for the master. In the most challenging situations, it will be necessary to repeat each step multiple times in order to get the ideal outcome.

Video. How to prepare a wall for decorative plaster

Preparation before applying textured and structural coatings

Unlike Venetian decor, structural and textured plaster lacks whimsicality. It fits well on any base, is not afraid of water, and lets the walls "breathe" freely. These characteristics enable the material to let in excess moisture from the room while preventing it from interfering with its natural outflow to the street. You can completely hide small flaws with its assistance (ornamental plaster beneath a tree is an excellent example).

Proper base preparation will ensure that the finish doesn’t peel off or get covered in cracks, keeping it looking great for decades. The primary benefit of the material is both its distinct texture and its texture. There will be two distinct patterns even if the same person makes the repair with the same equipment.

The prep work is manageable even for a novice:

• Remove all switches and sockets,
• First, clean the base from the old coating.
• Then remove greasy stains if any, wash with a weak soap solution.
• Next, level, seal cracks with a cement-sand mixture.
• Now you can apply the primer.
• After the composition dries, puttying is carried out.
• After the putty layer dries, it is covered with another layer of primer, but now with a special acrylic composition.
• It is carefully sanded using fine-grained sandpaper.

You can start applying the finishing coat after a day or so. Putty is not required if the textured or structural coating is applied in a thick layer with a pronounced relief (such as when imitating brickwork).

Tools and materials required for preparation

To remove old coating from walls and clean them for decorative plaster, you’ll need:

• Scraper. Used to clean the base from old wallpaper, paint. It can be replaced with a regular knife.
• Brush with metal bristles for dry method of removing whitewash.
• Chisel. Useful for cleaning from wallpaper, paint.
• Spatula. Useful for cleaning the base and when leveling the putty.
• Hammer, chisel, chisel. Useful for dismantling tiles.
• Needle roller. Needed to remove vinyl wallpaper that is resistant to moisture.
• Sandpaper for grinding.

Using specialized equipment, you can turn to:

• Grinding machine for leveling the surface.
• Electric drills with different attachments for cleaning and grinding the surface.
• A special steamer for removing wallpaper is already equipment for professionals.

What you’ll need to prime the surface is:

• Solution container.
• Roller
• Tassels.

You must inspect the wall with a plumb line and level before leveling it. PPE (masks, gloves, respirators), as well as covering material to protect the floor, will be necessary auxiliary materials.

How to prepare a wall: removing old coating

Taking off the last traces of the previous finish is the first step in hand-preparing walls for decorative plaster. The floor is covered with a polyethylene sheet that is fastened at the edges with heavy objects to prevent contamination.

De-energize every switch and outlet in the vicinity of the impending work. Moisture has the potential to get on them and result in a short circuit. Following the completion of the preparatory phase, you can start taking active measures.

Old plaster, tiles

The method used to remove outdated plaster varies depending on its state. There are several ways to quickly remove a thin layer:

• Wet it thoroughly. The soaked mass can be easily removed with a spatula.
• Use a hand float.
• Use a drill with a special brush attachment.
• Use a grinding machine that will remove a thin layer of the old finish and collect all the debris in the compartment of a construction vacuum cleaner (they need to be connected with a special hose).

Every approach has shortcomings. The room’s floor will be covered in sticky, wet dirt after using water. Fine dust is produced in copious amounts during "dry" removal. Working with a respirator is preferable. The newest technology will require specialized equipment for "clean work," which will come at a significant cost.

Using a chisel and hammer is sufficient if you are working with a thick layer of old finish that has already started to crumble and crack. It is simple to pry and knock off large pieces with their assistance. It can be left if the finish is in excellent condition (no cracks or other flaws) and is not crumbling.

A standard chisel can be used to remove ceramic tiles. During this work, a lot more heavy construction waste will accumulate, so it’s best to prepare containers for storage ahead of time. Ceramic tiles are reusable if they are carefully knocked off.

Removing old paint

A specific chemical composition (wash) or specialized tools (a hair dryer, a drill with an abrasive attachment) can be used to remove old paint. The painted base receives the solvent application in the first scenario. The composition softens it after a while. It is simple to remove the layer using a standard spatula. A thorough ventilation of the room is required after the paint is removed.

When working, safety glasses, a respirator, and gloves are necessities. Vapors of extremely toxic solvents are released.

The paint layer is fully heated and softer with a hair dryer. It can then be effortlessly taken off. Drilling or grinding is a very laborious cleaning technique, so it is not recommended for large surfaces.

It is recommended to prime the base with beton-kontakt, a special agent, after the paint has been removed. The mixture strengthens the adherence of aged tiles, alkyd and oil paints, concrete, and brick bases. Water should never be used to dilute beton-kontakt. Before using, the solution is well combined and applied in layers.

Removing old wallpaper

It is sufficient to rip the canvas in multiple spots and "remove" the wallpaper in pieces if it is extremely old and still depicts the events of the Great October Revolution. Water must be applied to stubborn areas before using a spatula or regular knife to clean them. To accelerate the wallpaper removal process, mix a few drops of dishwashing detergent or liquid soap into the water. You will need to get a specialized needle roller if you are working with tough vinyl wallpaper that is resistant to being wet. It will pierce the canvas sufficiently to allow water to seep through and soak the wallpaper.

An additional progressive technique is the use of a unique steamer. When the adhesive gets heated, the wallpaper peels off on its own. Professional craftsmen use a chemical solvent that you can purchase.

Removing whitewash

Three methods exist for removing whitewash:

• Wet method. Whitewash is thoroughly moistened with a sponge or sprayed with water from a spray bottle. After getting wet, the layer is scraped off. This method is inconvenient if you need to treat a large area. Whitewash dries quickly, so you will have to consistently clean small areas.
• Wet method for old whitewash. Multi-layer coating is first blotted and then scraped off with a spatula.
• Dry method. Suitable for a thin layer of whitewash, which is removed with a brush with bristles made of metal fibers. It is pre-fixed to a grinder or drill.

A lot of dust is released during the process of dry removal. Either use a respirator or a gauze bandage to protect the respiratory tract from its damaging effects.

No matter how good the whitewash is, it has to go when the walls are ready for decorative plaster to be applied. Lime’s ability to absorb moisture can cause the coating to peel and have a negative effect on it.

Surface repair

Removing any flaws that were discovered after the old coating was removed is the next step in priming the walls for decorative plaster. Defects such as chips, unevenness, and large and small cracks become:

• A consequence of errors made during finishing work.
• "Legacy" after long-term use.

If the surface repair stage is not included in the wall preparation process prior to the finishing finish application, the defects will eventually show up as new cracks or peeling sections.

1. Cracks are carefully cleaned before elimination, sanded if necessary and even widened so that the primer penetrates deeper.
2. After the primer has dried, the cut crack is filled with a material that is close in composition to the base material.
3. You can use a special liquid sealant. After it hardens, the excess is removed and the crack surface is sanded.

Use a reinforcing mesh to strengthen the surface if the crack is very deep and lengthy.

Putty and leveling

One common issue with apartments in new construction that was "hurriedly" constructed is uneven walls. A crucial step in surface preparation is the removal of such curvature. Plasterboard can be used to rectify severe curvature using the frame method. Sadly, the lathing will "eat up" a portion of the available area, which is an unacceptably high price to pay for small spaces.

You can use the same plasterboard (without a frame) or regular cement-sand plaster or gypsum mortar for minor curvature.

Wall leveling stages:

1. Primer of walls;
2. Installation of the beacons – install on the same solution that we align the wall;
3. We fill the space just below the level of the beacons with the solution (if the thickness is large – use the reinforcing grid);
4. We align the wall on the beacons by applying the finish layer;
5. After drying, remove the beacons, fill the remaining grooves.

Switch on the beacons from around the corner. Use the square and the level together during installation to prevent having a room that resembles a rhombombid afterward.

If we are talking about Venetian mixtures, putty is the necessary step in wall preparation before decorative plaster.

Putty comes in two varieties:

• Already a finished solution that is hermetically sealed in buckets of different containers.
• Dry powder requiring dilution.

The first option is more practical because the putty is uniform and comes to the surface easily; all you have to do is work with it. To get the right consistency, dry powder needs to be diluted in the right amounts and thoroughly mixed.

Since "ready" putty costs more than powder, people are less likely to choose it over powder when trying to save money. The surface is already smooth, so only a thin layer of putty is needed. It needs to be applied using various-sized spatulas. After the work is finished, sand the wall with fine-grain sandpaper.

Selection and application of primer solution

Priming is a step in the decorative plaster preparation process for walls. By applying the composition, you can improve the surface’s adhesion to the coating by increasing its adhesion. The primer fills in the material’s micropores, preventing mold or fungus from growing there and destroying it. Every material is given a unique primer. For instance, alkyd compounds work well with wood, perchlorovinyl compounds work well with concrete and brick, and acrylic compounds are thought to be universal.

Prior to applying finishing, primer is applied multiple times to walls in order to prepare them for decorative plaster. This is done after every step of the work (leveling, repair, etc.) is finished.

Type of Decorative Plaster	Preparation Steps
Venetian Plaster	Ensure the wall is smooth, clean, and dry. Apply a base coat of primer. Sand the surface for an even finish.
Textured Plaster	Remove any loose paint or wallpaper. Fill in cracks and holes. Apply a bonding agent if necessary.
Stucco Plaster	Clean the wall thoroughly. Apply a scratch coat to improve adhesion. Use a trowel to level the surface.

The secret to a successful decorative plaster finish is careful wall preparation. Plaster will adhere well and last for many years if the wall’s condition is evaluated, the surface is cleaned, and the required treatments are applied.

The fundamental preparation procedures—cleaning, repairing, and priming—remain the same, though particular steps may be needed for each type of decorative plaster. These steps will yield the best results whether you’re working with textured finishes, Venetian plaster, or any other kind.

You can lay a solid foundation for your decorative plaster with meticulous attention to detail during the preparation phase, which will facilitate the application process and enhance the appearance of the finished product.

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