Any room can be transformed by adding texture, depth, and a distinctive finish that stands out with decorative plaster applied to the walls. However, it’s essential to begin with appropriate wall preparation in order to get the best results. Ignoring this step or rushing through it can result in errors that will be challenging to fix in the future. For a perfect finish, it is therefore imperative that you take your time and thoroughly prepare your walls.
There are a few essential steps in preparation whether you’re working with recently installed drywall or old walls. These consist of sanitizing the surface, fixing any harm, and establishing a level, smooth foundation for the plaster to stick to. To make sure that your decorative plaster looks fantastic and lasts for many years, each of these steps is essential.
From getting the right tools to putting the finishing touches on your walls before you start plastering, this guide will take you through all the steps you need to take to get your walls ready for decorative plaster. You’ll position yourself for success and get a step closer to having the stunning, polished walls of your dreams by adhering to these easy instructions.
- Why do you need to prepare walls
- Technology
- Concrete wall
- Wooden surfaces
- Old plaster
- Brick base
- Drywall
- Aerated concrete / foam concrete
- Chipboard, OSB boards
- At the junction of different materials
- Video on the topic
- preparing the walls for decorative plaster
- SIMPLE Wall Putty | How to Prepare Walls for Decorative Plaster
Why do you need to prepare walls
Ignoring the preparatory phase can shorten the finish coating’s service life considerably.
- On dirty and uneven walls, plaster adheres worse, cracks may appear.
- Smooth surfaces need to increase adhesion. If you do not do this, the plaster will not adhere and will peel off over time.
- Before plastering, it is necessary to reduce the water absorption of porous materials so that they do not absorb moisture from the plaster mortar.
Technology
Preparing walls for decorative plaster is best done "for painting." The stages of this work include puttying, grouting walls, priming, leveling with gypsum or cement mortars.
Be aware that perfect smoothness is not always required. It is only required for smooth, thin-layer plasters like Venetian. Textured finishing coats that conceal small blemishes and imperfections on the walls include "fur coat," imitation stone, liquid wallpaper, and pebble plasters.
Tools required for the job:
- for removing the old coating: spatula, brush or scraper;
- for priming: paint tray, brushes and rollers;
- polyethylene film to protect the floor covering.
The type of material used to build the walls has a big impact on the preliminary work. Let’s look at the general guidelines that apply to both facade and interior design.
Concrete wall
Cement-sand mortar is used to level deep slab joints, and putty is used to fill in small imperfections.
Concrete panels themselves have a smooth surface. Gypsum plaster requires the use of an adhesion primer containing quartz sand (concrete contact) in order to adhere more readily.
Wooden surfaces
It’s crucial to keep in mind that wood can slightly alter in size in response to variations in humidity. This requires special methods to waterproof the surface in order to avoid deforming the plaster layer.
Laths are nailed to wooden walls as a base for reinforcement prior to plastering. For laths, use brushwood or narrow slats. Verify that the substance is not decaying. Both individual rods and pre-assembled lath boards are suitable for use. To avoid damaging the plaster, the ends need to be nailed to neighboring bases.
When hammering in nails, you cannot adhere to one axis to keep dry slats from splitting during fastening. At the edges, leave tiny spaces between the slats.
A reinforcing wire mesh can be used as an alternative to laths.
Old plaster
The coating needs to be closely examined before plaster is applied. Using a wooden hammer, tap the walls to locate any spots where the plaster is flaking off. These sections need to be taken out entirely, as do any pieces that have mold or grease stains.
Get rid of any old paint on the wall. A penetrating primer is used to strengthen loose plasters, like lime.
Brick base
For improved surface adhesion to the plaster, the joints between the bricks must be cleaned and, if necessary, deepened. has to be primed in order to lessen water absorption.
Such walls are usually leveled using heavy plaster that is based on cement. In this instance, strengthening calls for mesh reinforcement.
See our article for more information on plastering brick walls.
Drywall
Plastering should only be done with moisture-resistant materials; otherwise, the coating and surface may warp.
Processing the joints to create a smooth surface is required after the drywall is installed. We use putty for this. Before the mixture dries, remove any excess solution that may have been applied to the drywall sheets’ contact points.
Decorative plaster is typically used on drywall, replacing paint or wallpaper in the process. In order to improve adhesion, the surface beneath any planned gypsum mixture plastering needs to be primed with an adhesion primer. It is sufficient to prime the gypsum board with a universal primer before applying acrylic decorative plasters.
Aerated concrete / foam concrete
Cellular concrete generally adheres well to all kinds of plaster. However, it absorbs water very well, just like any porous material. The walls must be primed twice with an acrylic penetrating primer in order to stop moisture from the plaster solution from penetrating them.
Plastering the smooth, aerated concrete masonry with a gypsum mixture suffices for interior decoration. For damp rooms and the facade, use cement mortar or a specific adhesive mixture.
Using "wet facade" technology, insulation is often finished on the outside of the house.
Chipboard, OSB boards
Plastering is rarely applied to smooth chipboards (chipboard) because of the high likelihood of swelling when wet. However, if the technology is applied, this material can also be used as a foundation for ornamental plaster.
The same puttying technique used for plasterboard walls must be used on the joints between the boards. Use materials like concrete contact to improve the smooth surface’s adhesion to gypsum plasters or putties and to protect against moisture.
Cleaning is a crucial step before applying plaster to decorate or level walls made of any material because the adhesive does not adhere well to unclean surfaces.
- Greasy stains must be removed with a solvent or cleaned with a scraper/brush. After removing the wallpaper, you also need to remove the remaining pieces of paper.
- Dust and grains of sand from the walls must be swept away with a brush, damp cloth or vacuum cleaner.
- Almost always, the surface needs a primer. The composition is applied to the walls from the bottom up using a roller. In corners, near window openings, and in particularly difficult places, you can use a brush.
Putty is applied to the surface prior to the final decorative finishing, and once it has dried, it is rubbed with either fine-grained sandpaper or an abrasive mesh on a special bar. Without applying any force to the tool, grout is applied in circular motions until the surface is perfectly level.
At the junction of different materials
The plaster will dry and adhere differently on various materials. For this reason, after preparation, the areas where surfaces of various types are connected need to be reinforced even more with a reinforcing mesh.
Such a tape ought to have a minimum width of 20 cm. Dowels are used to secure the mesh to brick or concrete, and nails or screws are used to fasten it to wood.
| Step | Description |
| 1. Clean the walls | Remove any dust, dirt, or old paint to ensure the plaster adheres properly. |
| 2. Repair any damage | Fill in cracks and holes with filler, and smooth out any uneven areas. |
| 3. Apply primer | Use a primer to create a uniform surface that helps the plaster stick better. |
| 4. Sand the surface | Lightly sand the wall to ensure it’s smooth and ready for plastering. |
| 5. Protect areas | Cover floors and nearby surfaces to avoid any splashes or spills during plastering. |
For a smooth and durable finish, your walls must be properly prepped before applying decorative plaster. Rushing or ignoring these procedures can result in uneven surfaces, peeling, or cracks, all of which will detract from the project’s overall aesthetic. You can be sure that the plaster will adhere properly and look its best by taking the time to do it correctly.
To ensure that the plaster adheres to the walls, start by giving them a thorough cleaning to get rid of any dust, grime, or outdated paint. To create a smooth, even surface, fix any holes or cracks and smooth down any rough areas. Laying the foundation is essential to achieving a perfect finish in the end.
After that, use a primer or bonding agent appropriate for the kind of plaster you want to use. This stage guarantees that the plaster adheres correctly and dries uniformly. To prevent any problems during the application process, make sure you adhere to the manufacturer’s instructions regarding the drying times.
Finally, before you start plastering, take a moment to go over your work. A properly prepped wall facilitates the plastering process and guarantees an exquisite finish that will last for many years. The key to any decorative plaster project’s success is to dedicate time to preparation.
To guarantee a smooth, long-lasting, and aesthetically pleasing finish, there are a few crucial steps to take when preparing walls for decorative plaster. After giving the surface a thorough cleaning to get rid of any dirt, oil, and outdated paint, use filler to fix any holes or cracks. Next, use a bonding agent or primer to improve the plaster’s adhesion. Finally, before starting the plastering process, confirm that the wall is entirely dry and level. A faultless, long-lasting decorative plaster finish requires careful preparation.
