The easiest way to insulate a house is to sheathe it with foam. The material is inexpensive, installation is easy to do on your own, the energy-saving effect is obvious. And in order to protect such a sheathing from the harmful effects of the environment, you need to choose a suitable coating for it. The best option here is facade plaster, since it does not require large costs, and anyone can master the application technology.
Foam plaster, ready-made versions
Facade foam plaster
In addition to practicality, plastering has other advantages: such surfaces are easy to paint and finish with decorative plaster, which makes the facade especially attractive.
By choosing the right colors, you can make your home different from the others, emphasize architectural features or disguise flaws. Defects on the coating that appeared during operation can be repaired without much effort. But in order for the facade plaster to be of high quality initially, you should learn more about which compounds are suitable for this, and how to properly apply them to the foam.
The plaster is made of foam and painted in two shades
Insulated with foam and a plastered facade
When choosing a plaster composition, first of all, you need to take into account the characteristics of the foam. This material is not durable, so the protective coating must be sufficiently dense and resistant to mechanical stress.
Also, the plaster mixture must have high adhesion to the base, since the foam has a smooth surface. In addition, the plaster should be chosen moisture-resistant, plastic, easy to apply and not prone to cracking. But the vapor permeability of the composition does not matter much, since the vapor permeability of the insulation is very low.
Conventional cement-sand mixture meets these requirements only partially, and it is undesirable to use it on foam. Of course, this is the most budget-friendly composition, but after a year the facade will be covered with small cracks and everything will have to be redone.
Therefore, for finishing with foam, it is recommended to use only factory plasters containing special additives.
True, their service life is short - only about 10 years, and they have low plasticity, as a result of which the plaster cracks when the building shrinks.
Decorative mineral plaster, shades
The disadvantages of this type of mixtures include a high price and a tendency to burn out.
Acrylic facade plaster
What is good about acrylic plaster
The assortment of plasters for polystyrene is quite large, but there are brands that are in special demand: Ceresit, Stolit, Osnovit, Knauf, Ecomix. Manufacturers produce compounds of several types:
It is best for a beginner to choose a universal type of plaster that can be used at all stages of finishing with equal efficiency. But even if you prefer to use separate formulations for each process, they should all be from the same manufacturer, and preferably from the same line.
|A multi-purpose cement-based compound. Possesses good frost resistance (up to 75 cycles), water resistance and excellent adhesion. Consumption is from 3.5 to 7 kg / m2|
Ceresit CT 60
| Ready-to-use acrylic plaster. Designed for the formation of thin-layer decorative coatings. |
It has strength, elasticity and excellent water-repellent properties. Consumption ranges from 2.6 to 4 kg / m2
| Water-soluble polymer-based mixture, structural. Differs in excellent performance characteristics, has a high decorative effect. Consumption is 2. |
5-3.5 kg / m2
Foundation CAVERPLIX T-117
| Plaster and adhesive. It has excellent adhesion to polystyrene foam, water-resistant, frost-resistant. Consumption is 1.3-1. |
5 kg / m2
Foam plaster has its own characteristics. As a rule, the insulation itself is not primed, plaster compounds adhere to it so well. But to harden the coating, a reinforcing layer is required, otherwise cracks will appear very quickly. For reinforcement, fiberglass mesh of various densities is used, resistant to alkalis.The most comfortable to use is a mesh with a density of 140-160 g / m2 - it provides excellent grip and easily adjusts to the desired shape when finishing corner areas.
The leveling layer must be primed to increase adhesion between the topcoat and the base, and therefore a primer is also needed. The choice of the composition depends on what kind of coating is planned to be done: ordinary waterproof primers are used for painting, compositions with a quartz filler are required for decorative plaster.
Plaster mix must be purchased in full immediately and must be of the same brand. This is especially true for decorative plaster. The fact is that each manufacturer has its own manufacturing technology, and the compositions may differ in structure, color, setting time and other characteristics.
If you use different plasters on the same plane, after drying, transitions will be visible, and it is not at all easy to remove them.
In addition, before starting work, prepare the tools:
Tool for plastering walls
After finishing the façade cladding, carefully inspect the working area and remove minor defects. Empty seams must be filled with polyurethane foam, cut off excess glue with a knife, sand the joints with sandpaper. The surface must be flat, free from protrusions and depressions, free of dust.
If the foam slabs are too smooth, experienced builders recommend lightly sanding or rolling them with a special needle roller. This will increase the adhesion of the plaster to the insulation, and the coating will hold on tightly.
This stage is the most important , since the quality and durability of the coating depends on it. If the mesh is not secured correctly, the plaster will peel off from the wall during subsequent processing and will fall off in pieces.
Start by preparing the solution. They take a bucket, pour water into it with a temperature of 15-20 degrees, then pour in the dry mixture. Here you should strictly adhere to the proportions indicated in the manufacturer's instructions. Stir the mass with a mixer at low speed until smooth, leave for 5 minutes, then mix again. After that, add water or dry components, this can affect the strength of the plaster.
If a ready-made composition is used, it just needs to be mixed, in case the particles settle.
Step 2. The first to trim corners, slopes and areas with a complex configuration.For this purpose, perforated corners with a fiberglass mesh fixed to them are intended.
Reinforcing mesh with a corner
Some get by with the mesh itself, cutting it into strips 30 cm wide and bending it in half lengthwise.
The savings are negligible and the strength of the coating at the corners is noticeably lower, so it is better to use the corners.
So, they collect the solution on the spatula and apply it on both sides of the corner to the full height.
Set the mixture on a wide spatula
There is no need to level anything yet, the main thing is that the corner is covered with a solid strip. Next, apply a corner, lightly press it to the surface, check the vertical level. Smoothing, press the profile into the solution along the entire length, and then take a spatula and carefully smooth the mesh from the corner to the sides and down.
If necessary, add a little more mixture so that both the mesh and the profile itself are evenly deeper into the solution. Excess mass is removed with a spatula.
Step 3. After reinforcing the corners, proceed to the slopes. First, the corner is applied to the opening, the desired length is measured and the excess is cut off.
Then the solution is applied and the profile is fixed in the manner described above. If the width of the slopes is too small, it is more convenient to use the corners and the mesh separately. So the mesh will not puff up at the joints and interfere with work. To do this, cover one slope completely with a solution, fix the inner and outer corners, remove the excess mixture with a spatula. Cut off a strip of fiberglass mesh 10-15 mm wide less than the width of the slope and carefully apply it to the surface.
The side edges of the net should not reach the edge of the corners by about 5-7 mm. Smoothing is performed along the length of the strip, then to the sides.
Applying mesh to all corners (including slope corners)
Step 4. When all corners have been processed zone, you can start reinforcing the planes. Since the height of the outer walls is quite large, it is difficult to fasten the mesh with one sheet.
Therefore, it is recommended to cut the material into pieces 1-1.5 m long. The plaster mortar is applied to the surface in a continuous strip, starting from the edge of the wall. In height, this strip should be equal to the length of the net, and in width it should be 5 cm less. The layer is made about 2-3 mm thick.
Take a piece of mesh, apply it to the wall, level the edges. Then, with a wide spatula, smooth the mesh from the center to the sides and downward until all the material is immersed in the solution. The side edge of the net should remain free for a width of at least 5 cm. This is necessary so that the material does not form rough joints after overlapping.
How the fiberglass mesh is attached to the foam plastic
Cut off the excess
When reinforcing the surface, it is recommended to fix the mesh in such a way that its edges do not fall on the seams between the foam plates. All joints must be completely covered with a reinforcing sheet so that the coating is as strong as possible.
Construction reinforcing mesh
Step 5. Having secured the first piece, proceed to the next one. Here everything is exactly the same, only the edge of the mesh protruding from the solution needs to be slightly bent, and apply the solution under it too.
A new segment is applied with an overlap of 3-5 cm, smoothed with a spatula. After reinforcement, the surface should remain smooth, without sagging, stripes and grooves. Excess solution in the smoothing process is removed with a spatula and applied where there is not enough. It is not allowed to see through the mesh in certain areas, as well as voids under the reinforcing layer. Any defects made at this stage lead to a decrease in the quality of the finish.
Bonding plaster mesh
Bonding reinforcing mesh
No matter how hard you try to smooth the surface during reinforcement, there are still small irregularities that can appear under the finishing layer. To eliminate them, grout is performed using a plastic float with an emery cloth attached to it. The grain size of the skin is selected depending on the type of finish: for painting it is taken with fine grain, for structural plaster - with a large one.
Grouting is started after the plaster layer has dried, that is, after about a day. The grater is applied flat against the wall, pressed a little, begins to move in a circle counterclockwise.
The pressure force should be the same throughout the working process; you cannot rub for a long time in one area. Since the canvas wears out quickly, you will have to change it from time to time. After processing the entire area, the walls are cleaned of dust with a brush.
This time the solution is made more liquid - it should drain freely from the instrument, leaving a translucent continuous trace. The mixture is collected on a wide spatula and carefully applied to the wall with a thin layer - about 1-3 mm.
It is most convenient to process the surface in squares, and knead the solution in small portions to prevent it from solidifying. At the end of the process, you need to wait until the plaster dries, and then wipe the base again.
At the next stage, the facade is cleaned of dust and primed. For priming, use a short-haired roller and paint brush. The brush is used to process corners, ledges, slopes and other areas where it is inconvenient to work with a roller.
The primer is applied in 1-2 layers, depending on climatic conditions.
Finishing decorative plaster of the walls
So the primer is dry , you can start decorative plaster. Prepare the solution according to the instructions, stirring the dry components with water, or simply stir if a ready-made composition is used.It is applied with a wide spatula on the wall from bottom to top, observing the uniformity of the layer. The thickness of the application is usually equal to the size of the grains of the filler contained in the plaster, information about this must be found on the package of the mixture.
Plaster is applied in vertical stripes or squares.
Tip. In order for the entire plane to be uniform, without stains and transitions, it is necessary to plaster it at a time, taking breaks solely to prepare the next portion of the solution.
Having distributed the composition over the surface, they begin to form the relief. Most often, special graters are used for this, but you can form a pattern in other ways - with a sponge, a brush with stiff bristles, a spatula.
The most important thing is that the texture is the same throughout the entire area, and there are no transitions between areas. If the plaster is different in color, it can still be hidden under a layer of paint, but the embossed pattern cannot be masked.
Wall decor with a roller
How to make a relief with a spatula
At this, the finishing process can be considered completed. If desired, you can paint the facade if the plaster was not tinted.
Decorative plaster painted in two shades
Plastering on it is advisable to perform foam plastic immediately after the seams are dry.
The longer the insulation is exposed to the weather, the lower its thermal insulation properties. Moreover, you cannot leave such a house without finishing for the whole winter.
Plastering is necessary in dry warm weather and on a dry surface. The presence of moisture, dust, greasy spots on the foam negatively affects the adhesion of the plaster to the base, as a result of which the coating very quickly falls off in pieces.
When mixing the solution, strictly observe the proportions, do not add anything other than water.
The factory mixes already contain all the necessary components, and the presence of impurities will only worsen the quality of the plaster. Also respect the specified application thickness - it is better to apply 2 thin coats than one thick one.
Decorative plaster can give a home a unique exterior
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