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Smooth walls are an attribute of a good repair, but hiring a team is expensive. Puttying the walls with your own hands is not so difficult that it could not be dealt with. It is important to follow all the steps in sequence. It is unlikely that it will be possible to immediately get an ideal wall for painting, but you can putty under the wallpaper without much difficulty. And to help you, a description of the process, photos and videos.
What are and when to use
Puttying is the preparation of surfaces for finishing. With its help, they ensure that the wall is (or looks) perfectly even. It is applied to relatively flat surfaces. If you need to level the walls, bring out the corners of 90 °, do it with plaster or drywall. Putty is not intended for this.
Like plasters, putties consist of a binder, filler and additives that give them special properties. They are distinguished from plasters by the use of aggregates – sand – fine fractions. Two types of binder are used – cement or gypsum, sometimes lime, polymer additives are added to them. Accordingly, there are gypsum and cement putties.
There are also polymer putties – acrylic and latex. They are based on synthetic substances, the properties of which vary depending on the additives. They are not natural, but have a longer lifespan and withstand more freeze/thaw cycles. For facade work, it is better to choose them. Indoors, they are not the best choice, as they have low vapor permeability, which can cause damp walls, the appearance of fungus and mold. They are convenient in that they can be used on wooden and metal surfaces.
According to the type of application, all putties are divided into two types: starting and finishing. In the starting ones, grains of sand of a larger size are used – 0,3-0,8 mm. As a result, the surface is slightly rough. They are used at the first stage to seal cavities and cracks. In the finishing compositions, sand is practically dust with a very fine grain of 0,1-0,3 mm. This allows you to get a smooth surface.
Cement plasters – scope, advantages and disadvantages
Cement plasters are cheaper than gypsum plasters, they can be applied in a thicker layer – some compositions up to 10 mm. After mixing (mixing with water) they can be used for about 3 hours. The plasticity of the composition is affected by temperature and humidity. Usually it is specified for +20°C and 60-65% humidity.
Cement plasters are universal. They are used both for decoration inside the building and outside. Moreover, most of the facade compositions are made on the basis of cement, as they withstand more defrosting / freezing cycles and create a more durable surface. They also do best in damp environments. If you need to plaster a bathroom or kitchen, it is better to use a cement-based compound.
The color of cement plasters can be gray, white and ultra-white. It depends on the type of cement used. White compositions are more expensive, as more expensive brands are used, therefore finishing compositions are more often made white.
The disadvantage of cement plasters is a long setting time – several days for complete drying – this is the norm. It should take several hours before applying the next layer. From 2-3 hours with a layer of 1 mm, up to 24 hours with a thickness of 6 mm. Since it is rarely possible to achieve a smooth surface in one layer – there may be three or more – then puttying with cement plasters stretches for a long time. For this reason, their popularity is quite low.
Gypsum putties, their features
The layer of application of gypsum putty is 0,5-10 mm, depending on the type. They dry much faster, which has a positive effect on the speed of finishing work. On the other hand, the mixed composition must be used within 30-60 minutes, so such putties are kneaded in small portions. This is not very convenient. If you are going to putty the walls with your own hands for the first time, start with small batches. Gradually decide how much you can work out at a time. Also note that the consumption of the starting plaster is greater than the finishing plaster – the thickness of the layer is different and do not be mistaken in volume.
Gypsum plasters without modifying additives are intended for dry rooms. There are formulations for wet ones, but this must be indicated on the packaging, as they contain hydrophobic additives.
Despite the higher price and short shelf life of the closed portion, gypsum-based plasters are now more popular. They are more plastic, with their use it is easier to achieve the required smoothness of the surface, it is easier to work with them for beginners and professionals. If wall putty is still unfamiliar to you, use gypsum compounds.
Technology
The method of applying plasters is the same for any composition. What matters is only the observance of the recipe indicated on the package (the ratio of water and dry matter) and the time for which it must be used. The rest of the plastering technique is the same.
Substrate preparation
Work begins on a dry and clean base. If there is an old coating, everything that can fall is cleaned off, cracks are expanded, screws and nails, residues of wallpaper and other coatings are removed.
Sadly, both paint and whitewash must be removed. Paint for the reason that putty does not adhere well to it, and if it does stick, it may subsequently fall off. Whitewash is removed because it is loose. With it, after priming, the adhesion is normal, but after a while the finish begins to crack and flake off. If you do not want to redo the ceiling or wall in a year and a half, the lime must be cleaned off.
After the old coating is removed, dust is removed. If there is an industrial vacuum cleaner, you can use it (household is impossible – it will break). If there is no such equipment, you can walk first with a dry broom, then with a brush, and finally, with a slightly damp cloth, collect the remnants.
Primer
Priming walls for plaster is used to ensure that the materials adhere better. Its second task is to reduce the amount of moisture absorbed by the base. This is very important on porous surfaces such as brick, dry plastered wall, etc. On loose and crumbling walls, special deep penetration compounds are used. They bind the particles of the material to each other, increasing the overall strength of the base.
To get a guaranteed good result, it is better not to skip this step. Even despite the fact that primers cost a lot.
Primers are sold either as ready-to-use mixtures or as liquid concentrates. The second type requires additional dilution with water. In any case, before use, carefully read the instructions and follow them strictly.
Usually the technology is as follows: the composition is poured into the container, distributed over the surface with a brush or roller. In difficult places – corners and bends, thoroughly pass with a brush. If two or more layers are needed, they are applied after the previous one has completely dried.
Tools
Directly for puttying the walls you will need only two spatulas. One large, with a long blade (300-600 mm) and one small. The small composition is taken out of the container and distributed over the blade of the large one. They also remove the remnants from the blade and again distribute them along the edge. A large spatula is needed directly to distribute the composition on the wall.
The blade of a large spatula should be stainless steel. It should be flexible, without nicks and scratches. If you look at it “in profile” you can see that its ends are slightly bent to one side. This was done on purpose so that when puttying walls or ceilings, stripes from the edges of the blade do not appear on the surface. You can also work with a straight spatula, but at the same time you cannot get rid of the stripes, as a result – after drying you will have to compare them, and this is a long and dusty job.
You will also need a container in which putty and a construction mixer or a drill with a stirring nozzle are diluted. It is better to take a plastic container – a bucket or a basin with high sides. Pay attention to the shape of the bottom. The transition from the bottom to the walls should be smooth. Then it is possible to mix the entire composition without residue and lumps.
Wall putty technique
In general, everything has already been said, but let’s focus on the process and sequence of work. First, putty is kneaded. Water is poured into a bucket, a dry composition is added to it, making sure that there are no lumps. You have to wait for some time until the whole mass gets wet, then you can stir. Kneading can be mechanical or manual. This is indicated on the packaging with putty. When you have achieved a homogeneous composition without lumps, you can begin work.
It is necessary to apply putty on the wall with a large spatula. The composition is superimposed on it with a small one, forming a roller two to three centimeters wide and about a centimeter high on the edge of the blade. If the composition is thick, you can take more solution, if liquid, it can flow, because the roller is made small.
Step 1. Starting putty. If there are large irregularities – more than 3 mm, they are first covered with a starting putty. If the irregularities are only in places, only they are repaired, bringing them to the same level with the surface. If there are a lot of them, you will have to putty the entire surface. RџSЂRё work it is advisable not to exceed the maximum allowable layer thickness, otherwise cracks may appear or the finish will fall off. If there are no significant irregularities, you can do without this layer. But in this case, the consumption of the finishing composition will be greater, and it costs more than the starting one.
The thickness of the putty layer that remains on the wall is regulated by the angle of the spatula. If it is strongly inclined to the wall, the layer remains thicker, if the angle is closer to a straight line (60-70 °) – it can be 1 mm.
There is another technique for applying putty. It’s called “on the edge”. In this case, the spatula is placed perpendicular to the wall. As a result, only pores, stripes and other defects are smeared, the consumption is minimal. But this technique only works on flat walls, without deviations in geometry. Puttying uneven walls with differences of more than 1-2 mm using this technique is impossible.
Step 2 Leveling the First Layer. After the starting layer has dried (the time is indicated on the package), sandpaper is taken for grinding and the most prominent irregularities are leveled with it. Most often these are stripes, but due to inexperience, bumps can also appear. After grinding is completed, the dust from the walls is swept away with a broom, then they pass with a dry brush.
Step 3. Finishing wall putty. A layer of finishing putty is applied to the cleaned walls, no more than a few millimeters thick. At this stage, it is already necessary to try to get a flat surface, carefully leveling the composition. Leave to dry.
Step 4 Aligning the Finishing Layers. For this stage, a grid with a smaller cell is taken. Trying to get a flat surface. Good lighting is essential for good results. Also, the absence of defects is checked with the palm of your hand.
That’s all. Then steps 3 and 4 are repeated until the result satisfies you. A little about the extent to which it is necessary to align the walls. It all depends on the type of finish you choose. If the wall putty is made under the wallpaper, there is no need to achieve perfect smoothness. Even the thinnest wallpaper hides small differences. Less demanding on the surface of multilayer paper wallpaper – duplex or triplex. A more even base is necessary for a non-woven base, as well as for all vinyl wallpapers except for foamed and textured ones.
The requirements for putty for painting are higher. The paint does not hide even the most minor flaws, so you have to level to perfect condition. Up to six very thin coats may be needed.
How to make smooth corners with putty
Several ways you saw in the video – it’s just good to shoot the mass from the very corner. Everything seems simple, but in practice it turns out with difficulty and not very smoothly. There are special corner spatulas for novice plasterers for the outer and inner corner.
Having applied a certain amount of putty to the corner, they are carried out, removing the excess and forming an ideal line. They are easier to work with.