Priming the walls before wallpapering

The quality and durability of wallpapers, pasted during the process of major or cosmetic repairs, largely depends on the correct approach to the preparation of the substrate. If before, before wallpapering the room, it was necessary to pre-glue the walls with newspapers or wetting with dilute wallpaper paste, then today it is enough to make only the priming of the walls in front of the wallpaper.

Primer application

Primer is a compound produced on the basis of natural or synthetic film-forming elements with the addition of a small amount of pigments and fillers.

Compared to newspapers and wallpaper paste, which in the recent past have only contributed to the improvement of adhesion between bonded materials, the priming of walls before wallpapering performs a number of additional functions:

• is a strong grip of the upper layer of the substrate, preventing cracking and subsequent plastering of the plaster,becomes more dense structure;
• leveling of minor depressions, thereby reducing the risk of air pockets;
• decrease in the absorbent capacity of the surface to be treated, as a result of which the wallpaper glue is applied evenly, thus contributing to savings in adhesive composition;
• semi-matt film eliminates the translucence of a concrete or other dark base through thin wallpaper;
• protects wallpaper from fungus, mold, since the film formed after drying the primer prevents condensate from accessing the wallpaper directly;
• cleans the surface of construction dust, which degrades the quality of the bonding of materials.

Thus, a primer for walls under the wallpaper is a fairly significant point in the preparation of the surface for subsequent finishing works. However, the quality and duration of the problem-free operation of the wallpaper largely depends on the compatibility of the primer and the surface to be treated.

The choice of

primer The characteristics of the huge number of primers present on the market today are largely determined by the substances and elements used in the process of making the composition, which have different effects on concrete, metal, plastered surface, wood coating, etc.

Depending on the degree of impact on the surface to be treated, the entire variety of primer compositions is divided into:

• reinforcing - only the surface layer of the wall acts without penetrating the structure of the material. When the priming composition dries, a film 1-2 mm thick is formed. Primers of strengthening character are ideally suited for processing of wooden, metal surfaces;

• - penetrate not only on the surface of the base, but also on the structure of the material being processed. Primers of deep penetration contain binders 10 times smaller than reinforcing compounds, allowing the mixture to penetrate deeper layers of the processed material, reaching a thickness of 1 cm. Most often used for priming of puttyped surfaces, concrete and other materials prone to destruction and shattering.

Based on the main component, the primers are divided into alkyd, mineral, acrylic, perchlorovinyl, glyptal and many others. However, when finishing works inside the premises are more suitable:

1. Acrylic formulations are used for priming any coatings. The only exceptions are metal surfaces, as rust eventually seeps through the protective film, since primers on acrylic base rarely contain anti-corrosion additives. The main features of acrylic primers are:

• no specific odor;
• ease of cleaning used for priming tools under a stream of warm water;
• the drying speed of one layer, taking 1-4 hours.

However, the water-based base of acrylic primers reduces the resistance of the film coating to the negative effects of the environment, and is therefore suitable for work at temperatures above + 10 ° C.

2. Alkyd compounds are produced on an organic basis and contain anti-corrosion elements, therefore they are used for processing metal as well as wooden coatings. Strengthening primers on an alkyd base are highly resistant to various kinds of pollution, as well as good weather resistance, which allows them to be used for priming the walls of the veranda, summer kitchen. However, the presence of a specific smell causes the need for airing the room during the work until the composition dries completely. Unlike acrylic, alkyd primers dry throughout the day. In addition, the tools after the completion of the work will have to be thrown out, because they can not be completely washed.

Thus, when choosing a primer, it is worth considering the humidity level in the room, as well as the material on which the primer is applied. In most cases, the optimal variant of the primer for wallpaper is the acrylic composition of deep penetration.

Surface preparation

Before applying the primer to the walls, it is necessary to prepare the surface in the following way:

• to get rid of adhesive residues, wallpaper on the wall by means of spatula and water;
• remove mold from the walls, if any, by applying a chlorine solution, followed by washing the treated area with warm water;
• clean the wall of the peeling pieces of putty with a spatula, sand the rust on the metal with sandpaper, remove the burrs and roughness from the wood;
• with a brush moistened in the acquired primer, moisten the defective spots and putty;
• check the drying of the putty places with a piece of cellophane pasted on the wall measuring 15x15 cm. To do this, in the evening, the cellophane is glued to the wall with adhesive tape from all sides. If there is no condensation under the polyethylene in the morning, the putty is completely dry and you can go to the primer of the walls( see the video at the end of the article).

Priming application process

Before proceeding to priming the walls directly, it is advisable to protect any exposed areas of the skin, since the constituent elements of the primer can cause an allergic reaction.

Primer walls before gluing must begin at least a day, so that each layer, and they must be at least 2, had time to dry out thoroughly.

On the prepared surface, the primer is applied by means of a foam roller or sprayer, and in hard-to-reach places - by means of a wide brush.

The work is carried out in the following order:

• the places of the eliminated faults are moistened;
• after drying the primer is applied evenly over the entire surface, not forgetting to process all the corners;
• the next coat of primer is applied similarly to the first in 3-4 hours.

After complete drying of all layers of the applied primer, it is possible to dilute the glue and start finishing the walls with wallpaper.

Thus, if the primer composition is correctly selected and the priming of the walls is properly carried out, the wallpaper is unlikely to be peeled off.