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Applying a reinforcing layer to foam plastic. Plastering work on polystyrene foam. Why is a plaster mesh needed and how to install it

The easiest way to insulate a house is to cover it with polystyrene foam. The material is inexpensive, installation is easy to do on your own, and the energy-saving effect is obvious. And to protect such cladding from the harmful influence environment, you need to choose for her suitable covering. The best option here is facade plaster, since it does not require large expenses, and anyone can master the application technology.

Plastering on foam plastic, ready-made options

Facade plaster on polystyrene foam

In addition to practicality, plastering has other advantages: such surfaces can easily be painted and finished with decorative plasters, which gives the facade a special attractiveness. By choosing the right colors, you can make your home different from others, highlight architectural features or disguise flaws. Defects in the coating that appear during operation can be restored without much effort. But in order for the plastering of the facade to be of high quality from the very beginning, you should learn more about what compositions are suitable for this, and how to properly apply them to foam plastic.

The plaster is made using foam plastic and painted in two shades

Foam insulated and 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, you need to choose a plaster that is moisture-resistant, plastic, easy to apply and not prone to cracking. But the vapor permeability of the composition is not of great importance, since the vapor permeability of the insulation is very low.

A conventional cement-sand mixture only partially meets these requirements, and it is not advisable to use it on foam plastic. Of course, this is the most budget-friendly composition, but within a year the facade will be covered with small cracks and everything will have to be redone. Therefore, for finishing on foam plastic, it is recommended to use only factory-made plasters containing special additives.

Cement-sand plaster

The range of plasters for foam plastic is quite large, but there are brands that use special demand: Ceresit, Stolit, Osnovit, Knauf, Ecomix. Manufacturers produce several types of formulations:

• for attaching insulation to the base;
• to create a leveling layer;
• universal.

It is best for a novice master 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 compounds for each process, they should all be from the same manufacturer, and preferably from the same line.

Knauf Sevener	A universal-purpose cement-based composition. It has good frost resistance (up to 75 cycles), water resistance and excellent adhesion. Consumption ranges from 3.5 to 7 kg/m2
Ceresit ST 60	Acrylic plaster, ready to use. 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
Stolit AF	Water-soluble polymer-based mixture, structural. It has excellent performance characteristics and is highly decorative. Consumption is 2.5-3.5 kg/m2
Founds CAVEPLIX T-117	Plaster and adhesive composition. Has excellent adhesion to polystyrene foam, waterproof, frost-resistant. Consumption is 1.3-1.5 kg/m2

Plastering technology

Materials for work

Plastering on polystyrene foam has its own characteristics. As a rule, the insulation itself is not primed; plaster compounds adhere to it well. But to strengthen the coating, a reinforcing layer is required, otherwise cracks will appear very quickly. For reinforcement, fiberglass mesh of various densities, resistant to alkalis, is used. The most convenient to work with is a mesh with a density of 140-160 g/m2 - it provides excellent adhesion and easily takes the desired shape when finishing corner areas.

Fiberglass mesh

The leveling layer must be primed in order to increase adhesion between the topcoat and the base, and therefore a primer will also be needed. The choice of composition depends on what kind of coating is planned: for painting, ordinary waterproof primers are used, for decorative plaster, compositions with quartz filler are required.

The plaster mixture must be purchased immediately in full and always 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 used on one plane different plasters, after drying, transitions will be visible, and eliminating them is not at all easy.

Additionally, before starting work, prepare the following tools:

• short pile roller for priming;
• metal spatulas, narrow and wide;
• plastic grater with emery cloth;
• construction mixer;
• plastic corners with reinforcing mesh.

Tool for plastering walls

Preparing the base

After completing the façade cladding, you need to carefully inspect the working area and eliminate minor defects. Empty seams must be filled with polyurethane foam, excess glue must be cut off with a knife, and the joints must be cleaned with sandpaper. The surface must be smooth, without protrusions or depressions, and free of dust. If the foam slabs are too smooth, experienced builders recommend lightly sanding them or rolling them with a special needle roller. This will increase the adhesion of the plaster to the insulation, and the coating will hold tighter.

Foam insulated wall

Fastening the reinforcing mesh

This stage is the most critical, since the quality and durability of the coating depends on it. If the mesh is not secured correctly, during subsequent processing the plaster will peel off from the wall and fall off in pieces.

Step 1. Start by preparing the solution. Take a bucket, pour water at a temperature of 15-20 degrees into it, then add the dry mixture. Here you should strictly adhere to the proportions specified in the manufacturer's instructions. Mix the mixture with a mixer at low speed until smooth, leave for 5 minutes, then mix again. You cannot add water or dry ingredients after this, as this may affect the strength of the plaster. If used ready-made composition, you just need to stir it in case the particles settle.

Step 2. The first to finish are corners, slopes and areas with complex configuration. Perforated corners with a fiberglass mesh attached to them are designed for this purpose.

Reinforcing mesh with corner

Some make do with just the mesh itself, cutting it into strips 30 cm wide and bending it in half lengthwise. The savings here are insignificant, and the strength of the coating on the corners is noticeably lower, so it is better to use the corners.

So, take the solution onto a spatula and apply it on both sides of the corner to its entire height.

Set of mixture on a wide spatula

There is no need to level anything yet, the main thing is that the corner is covered with a continuous strip. Next, apply a corner, lightly press it to the surface, and check the vertical level. When leveling, press the profile into the solution along its 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 immersed in 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 required length is measured and the excess is cut off. Then the solution is applied and the profile is secured in the manner described above. If the width of the slopes is too small, it is more convenient to use the corners and mesh separately. This way the mesh will not bulge at the joints and interfere with work. To do this, cover one slope completely with the solution, attach the inner and outer corners, and remove the excess mixture with a spatula. Cut a strip of fiberglass mesh 10-15 mm wider than the width of the slope and carefully apply it to the surface. The side edges of the mesh should not reach the edge of the corners by approximately 5-7 mm. Smooth along the length of the strip, then to the sides.

Gluing the mesh to all corners (including slope corners)

Step 4. When everything is processed corner areas, you can begin to reinforce the planes. Since the height of the external walls is quite large, it is difficult to attach the mesh with one sheet. Therefore, it is recommended to cut the material into pieces 1-1.5 m long. The plaster solution is applied to the surface in a continuous strip, starting from the edge of the wall. The height of this strip should be equal to the length of the mesh, and the width should be 5 cm less. The layer is made about 2-3 mm thick.

Mesh reinforcement

Take a piece of mesh, apply it to the wall, and even out the edges. Then, using a wide spatula, smooth the mesh from the center to the sides and down until all the material is immersed in the solution. The side edge of the mesh must remain free to a width of at least 5 cm. This is necessary so that the material does not form rough joints after overlapping.

How is fiberglass mesh attached to polystyrene foam?

Trimming the excess

Fixing the mesh

Step 5. Having secured the first piece, proceed to the next. Everything is exactly the same here, only the edge of the mesh protruding from the solution needs to be slightly bent, and the solution must be applied under it too. The new piece is overlapped by 3-5 cm and smoothed with a spatula. After reinforcement, the surface should remain smooth, without sagging, stripes or grooves. During the smoothing process, excess mortar is removed with a spatula and applied where it is missing. It is not allowed to show 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.

Gluing plaster mesh

Gluing reinforcing mesh

Grouting the surface

No matter how hard you try to smooth the surface when reinforcing, there are still small irregularities that can appear under the finishing layer. To eliminate them, grouting is done using a plastic float with an emery cloth attached to it. The grain size of the sandpaper is selected depending on the type of finishing coating: for painting use fine grain, for structural plaster - with coarse grain.

Sanding block

Grouting begins after the plaster layer has dried, that is, in about a day. The grater is applied flat to the wall, pressed a little, and movements begin in a circle counterclockwise. The pressure force should be the same throughout the working process; you cannot rub in one area for a long time. Since the fabric wears out quickly, you will have to change it from time to time. After treating the entire area, the walls are cleaned of dust with a brush.

Final alignment

This time the solution is made more liquid - it should flow freely from the instrument, leaving a translucent continuous trace. Scoop the mixture onto a wide spatula and carefully apply it to the wall in a thin layer - about 1-3 mm. It is most convenient to treat the surface in squares, and mix the solution in small portions to prevent it from hardening. Upon completion of the process, you need to wait until the plaster dries, and then rub the base again.

Final alignment

Leveled wall

At the next stage, the facade is cleaned of dust and primed. For priming, use a short-nap roller and paint brush. The brush is used to process corners, protrusions, 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.

Application of decorative plaster

Finishing decorative plaster of walls

So, the primer has dried, you can start decorative plaster. Prepare the solution according to the instructions, stirring the dry ingredients with water, or simply stir if using a ready-made composition. Apply it with a wide spatula to the wall from bottom to top, ensuring the uniformity of the layer. The thickness of application is usually equal to the size of the filler grains contained in the plaster; information about this must be on the packaging of the mixture. Apply plaster in vertical stripes or squares.

Advice. In order for the entire surface to be uniform, without stains or transitions, it is necessary to plaster it at a time, taking breaks only 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, or a spatula. The most important thing is that the texture is the same over the entire area, and there are no transitions between areas. If the plaster is different in color, this can still be hidden under a layer of paint, but the relief pattern cannot be masked.

Wall decor with roller

How to make a relief with a spatula

Decorative plaster painted in two shades

It is advisable to perform plastering on foam plastic immediately after the seams have dried. The longer the insulation is exposed to atmospheric influences, the lower its thermal insulation properties. Moreover, such a house cannot be left unfinished for the entire winter.

Plastering should be done in dry, warm weather and on a dry surface. Presence of moisture, dust, greasy stains on polystyrene foam negatively affects the adhesion of the plaster to the base, as a result of which the coating very soon falls off in pieces.

When mixing the solution, strictly follow the proportions and do not add anything other than water. Factory mixtures already contain all the necessary components, and the presence of foreign impurities will only worsen the quality of the plaster. Also follow the specified application thickness - it is better to do 2 thin layers than one thick one.

Plastered surface

Decorative plaster can give a house a unique exterior

Video - Facade plaster on polystyrene foam

Video - Plastering slopes using foam plastic

Do-it-yourself facade plaster on polystyrene foam

The issue of external wall insulation, both in the private sector and apartment buildings, is gaining more and more relevance every year. More and more owners prefer to spend money on external insulation once rather than pay huge fees annually public utilities. Choosing between a range of materials for external insulation, are increasingly focusing on polystyrene foam. This construction material has many advantages: high level heat preservation, low cost, ease of installation. However, when working with the material, you should not neglect protection from environmental influences. And plastering will give maximum protection to the foam.

When choosing between a range of materials for external insulation, more and more people are choosing polystyrene foam

You will learn in more detail about this method, as the most optimal one, for protecting your foam block house, or rather its external insulation. You will also be presented with the technology of applying a plaster layer on polystyrene foam, and the features of working with the material.

If the decision has already been made, and out of all the many materials for insulation you have chosen polystyrene foam, or its close relative - penoplex, you need to think about its protection from external destroyers coming from the environment: moisture, sunlight, ultraviolet radiation, high and low temperatures. And we will protect it by plastering.

Stages of plastering a surface made of foam plastic or penoplex

To understand the whole process, as well as the necessary materials, you need to know what stages it includes:

• Preparation of plaster mortar.
• Plaster mesh and its fastening to the surface.
• Grouting work on mesh for plastering.
• Layer to level the surface.
• Grouting work on a layer for leveling.
• Surface primer.
• Final works.

If you understand each stage of the work in detail, you can understand that the process, although long and labor-intensive, can be divided into several days. This is especially true for novice craftsmen who are just trying their hand at plastering. A little training and your hands will know what to do, and all you have to do is enjoy the process. In addition, this is an excellent option to save on hiring a team of professionals who will perform plastering just as well as you, but will ask for a considerable amount of money for it.

Preparation of plaster mixtures

To work with polystyrene materials, which include polystyrene foam and the like, it is necessary to use ready-made mixtures, specially designed for such work. Various companies producing dry building mixtures, have in their assortment several options for such mixtures. Also, depending on the manufacturer, price and quality will fluctuate. Over the years, companies such as Ceresit and Ecomix have successfully established themselves. You can use mixtures of these companies or choose cheaper options. But when saving on mixtures, it is worth remembering that the final quality of the work performed depends on the quality of the material. Please also take into account the fact that you should not use mixtures from different companies in one area of ​​work; they may differ in structure and color.

It is very convenient to choose a mixture that is universal. It can be used both as an adhesive material for attaching foam to the wall, and as a layer of protection. There are companies that have two types of mixtures in their assortment: separately for mounting the slab and separately for protection. When purchasing materials, do not be lazy and read what is indicated on the package; perhaps this mixture will not suit you.

The mixture, which is universal, is used for installing a special mesh to the wall for plastering, as well as for other plastering work. The material is consumed quite a lot, so for large volumes it is necessary to stock up on several bags. To apply one square meter of plaster mesh you will need up to four kilograms of the mixture, and to level the wall you need six kilograms per square.

The method of preparing the mixture itself is quite simple and is often indicated on the packaging. It is necessary to follow all instructions to obtain the highest quality material. To secure the mesh for plastering, it is best to use a mixture not of the thickness recommended by the manufacturer, but a little less often. When the leveling layer is applied, the consistency should be completely liquid, practically flowing off the working tool.

In principle, everything is quite clear with the technology for preparing mortar for plaster. Now you can get down to business and glue the mesh for plastering, because it is the main layer for applying the plaster.

Installation of plaster mesh to the wall

Before you start plastering the main insulating material - polystyrene foam, you should make sure that the leveling mixture and the plaster itself have reliable adhesion to the working surface. Polystyrene foam itself does not have good adhesive properties; if you apply plaster to a cut, it will at least crack, and at most it will disappear altogether, and then all the work and costs will go down the drain. To avoid this, it is necessary to use a plaster mesh.

Installation of plaster mesh to the wall

Which grid should you choose? If you work with external insulation, then you suitable material for facade work. This mesh is distinguished by its density, and the denser the mesh, the better the layer of plaster lays down. However, there is a small nuance: if the mesh is too dense, it will be quite difficult to work with the corners. It is best to take a mesh for plastering with a density of 140-160 grams per square meter. Another piece of advice for novice finishers: it is best to take the mesh that is resistant to alkali, due to the fact that The basis of the plaster mixture is cement.

Where to start installing the mesh for plastering - the correct answer is from the corners. Moreover, not only corners, but also slopes, both windows and doors, are glued first.

The process of gluing the mesh to the corners:

1. The mesh for plastering, which is intended for installation in a corner, is a strip whose width is 30 centimeters. The length of the mesh will depend on the surface being treated. If these are slopes, then we focus on their length, if the corner of the house is about one meter.
2. Next you need to make a bend in the middle of the grid. This is necessary in order to impart a certain rigidity even after the pressure from the mesh is removed.
3. Then you need to arm yourself with a spatula and use it to apply the plastering mixture to the required part: be it a corner or a slope or a door opening. The layer of the applied mixture should be quite thin and not exceed three millimeters.
4. After applying the mixture to the corners or slopes, you need to apply a plaster mesh, press it with a spatula and smooth it away from the corner and towards the bottom.

The process of gluing mesh to the walls:

When the work with the corners is completed, you can begin gluing the plaster mesh to the walls. Please note that it is necessary to leave parts of the corners not glued; they will be used at the time of joining.

1. The mesh for plastering, it is sold in rolls, must be cut into pieces no more than one meter long. Installation takes place in separate pieces due to the fact that the universal mixture dries quite quickly.
2. The prepared wall must be covered with a universal mixture; the dimensions of the coated part are approximately 1 meter by 90 centimeters. We need the 10 centimeters that remain to glue the joints. The mixture is best applied with a small spatula, about 35 centimeters, and the layer thickness is about three millimeters.
3. Next, as in working with a corner, you need to lay the mesh for plastering to the wall and press it down with a spatula. Using smoothing movements, secure it to the wall, movements from the center and to the edges, also from top to bottom. The mesh itself is almost completely immersed in the plaster mixture; you can completely cover the mesh with the mixture; to do this, you need to apply it a little on a spatula while pressing down.
4. This must be done with each vertical strip, gradually moving to the side. Please note that the mesh is laid overlapping, for the purpose of further processing of the joints. The same docking occurs in corner places.

Grouting on plaster mesh

When the process of installing the mesh for plastering is completed, the resulting layer must be wiped down. This can be done using a regular grater; it can be plastic or wooden and is sold in any hardware store. Sandpaper is used as a grouting cloth.

You should not start grouting immediately after attaching the mesh. Let the work surface dry thoroughly. If you are doing repairs in the warm season, then it will only take a few hours, if this autumn period, when it is damp and humid, it is better to wait a day, or even more.

Grouting on plaster mesh

The grouting process is simple and even a teenager can handle it. Using light force, work the work surface in a circular motion. It's best to do it counterclockwise. If wet pieces get on the sandpaper, it should be replaced.

Applying a layer for leveling

The next step on the path to reliable and high-quality insulation walls with polystyrene foam is applied as a layer for leveling. As a mixture, you can use a universal mixture for plastering walls. It should be remembered that the leveling layer must be applied only to a previously rubbed surface.

The process of applying a leveling layer:

1. Arm yourself with a wide spatula, it is better if it is more than 35 centimeters; you need to apply the mixture to its surface for leveling. This can be done with a smaller spatula.
2. Carefully, with smooth and confident movements, apply the mixture with a spatula to the wall. If the surface grouting was of high quality, then a layer will be enough to level the surface up to three millimeters thick.
3. It is better to move the joining of the leveling layer away from the places where the mesh joins, so the seams will be less noticeable and of better quality.

Grouting of the leveling layer

Nothing new has been invented for this work, so we rubbed the leveling layer according to the same principle as we rubbed the mesh. It is also worth remembering that all grouting work occurs only on a dry surface. However, remember that it is best not to let the leveling layer sit, otherwise you will have to rub it with special efforts. The best period for grouting is 1-4 days.

How do you know that rubbing a layer for leveling is enough? It's very simple, rely on your vision. When you notice that the layer is quite even and smooth, you can move on to the next section. After grouting the leveling layer, you already have a finished surface, which involves finishing work, for example, applying decorative plaster or texture.

Finishing the facade with foam plastic and plastering video

Surface primer

Quite often, inexperienced or novice craftsmen neglect such a stage as priming, and in vain. The process itself is not only low-cost financially, but also in time, and the benefits from it are invaluable. Initially, the primer absorbs all residual materials after grouting, thereby reducing the absorption of the surface of the applied materials. You can also use an antifungal primer; it will save you from getting the walls wet and mold, and the finish itself will adhere better to a primed surface.

The primer is applied to the surface using a short-pile roller; you can also use a foam roller. It is necessary to work carefully to avoid the formation of drips. Next, we wait until the soil is absorbed and dried, after which we can begin decorative finishing.

Final plastering work on polystyrene foam

Decorative plaster is especially popular; it is what is most used for finishing. It must be applied to a well-primed work surface after complete drying.

The process of applying decorative plaster:

1. Again, we arm ourselves with a spatula and use it to apply the plaster mixture. It is very important to ensure that the layer applied to the surface is the same in all areas. Also, the thickness of the layer depends on the grain size of the plaster: the larger it is, the denser and thick layer applied.
2. When the layer is applied, it is necessary to form the texture of the plaster. To do this, you can use various special rollers or improvised materials. You can make bark beetle plaster, it looks very interesting and is quite simple to do.
3. After creating the texture of the plaster, you need to leave it until it dries completely, after which you can start painting the surface.

Watch this useful video: How to insulate a house with polystyrene foam. All stages

Now you know all the features of working with foam insulation, as well as its plastering technology. Quite simple and incredible reliable way insulate your home with your own hands.

Copyright © 2018 | When using site materials, a backlink to www.svoimi-rukamy.com is required!

No matter how wonderful and effective foam insulation is, its durability under climate attacks is relatively short; today experts estimate the period of degradation and disintegration of foam at a maximum of 18 months. The best way To save your work and insulate the house, apply façade plaster over polystyrene foam. Such protection will preserve foam insulation at home, even if finishing and plastering work was carried out with minimal experience and skills.

What is the best way to cover foam from the sun?

There are many commercials and advice from would-be experts that polystyrene foam is not afraid of water and frost, does not react to air humidity, and its only drawback is solar ultraviolet radiation. Such “tips” suggest not laying plaster over foam plastic, but covering it with a screen made of paint mesh and a thin layer of reinforcing glue until better times.

This cannot be done, if it is planned to finish the facade of the house with foam plastic and plaster, then the entire complex of work must be completed in a maximum of one season, and best of all, in two to three weeks, no more. Polystyrene foam does not provide an airtight layer without plaster; even when laid on good mineral glue and a primed surface of the walls of the house, it retains heat but allows water vapor to pass through.

The sequence of work when finishing the facade with foam plastic and plaster is as follows:

• The surface of the building walls is primed. If the layer of plaster on the brick is relatively fresh and does not stain your hands, then you don’t have to apply a primer, but the feasibility of such savings is small;
• Glue the foam sheets onto the foam or façade adhesive;
• Place a reinforcing sublayer of protective adhesive with a fiberglass mesh on the foam plastic;
• Align the corners of the walls and slopes on the windows;
• Lay a leveling sublayer of plaster;
• Rub and clean the base, finish the finished wall surface with decorative plaster.

Advice! If force majeure circumstances do not allow you to complete the entire scope of work and lay the protective finish on the foam insulation layer, at least lay a mesh with a reinforcing adhesive layer and apply a deep penetration primer with an acrylic base to the dried surface.

All the same, before plastering the foam on the outside, in the future it will be necessary to apply deep penetration primer; this operation cannot be avoided. It does not affect the properties of foam plastic, since it is water-based, and it can protect the facade surface lined with foam plastic from water and sun very well. But such protection will not replace a full-fledged plaster coating; its durability is at most 6-9 months, just until the next construction season.

The process of applying a protective sublayer to foam plastic is considered one of the most complex and important stages. In this case, you cannot save on materials and work, otherwise cracks will appear when finishing the facade with foam plastic plaster. Therefore, let’s first think about glue and mesh for applying protective plaster.

Materials for performing facade plaster

Construction and finishing work are always costs, and sometimes considerable ones. Count and purchase exactly according to the estimate several types of different plaster mixtures and adhesive compositions how they do experienced craftsmen, It's hard enough. Therefore, there is a certain temptation to simplify your life when laying facade plaster over foam insulation.

You can find a fairly large number of ready-made adhesives on the market. Famous brands Ceresit, Kreisel, which is simpler - Stolit, Master produce both universal and specialized adhesive acrylic-cement compositions. The former are cheaper, but it is better not to use them. Therefore, to arrange a reinforcing layer for façade plaster for polystyrene foam, we select the following materials:

• Special adhesive for arranging a reinforcing layer of plaster on polystyrene boards. No adhesives for ceramics or sticking foam on the walls, this is a completely different material;
• Fiberglass mesh with a density of 150-160 g/m2 for an alkaline environment. This facade mesh has a special protective coating that improves the adhesion of the fibers to the adhesive mass.

The adhesive itself for arranging the reinforcing layer due to additives is characterized by a pronounced alkaline reaction, this allows the adhesive mass to adhere well to façade walls lined with foam plastic. Any other adhesive mass practically does not stick or sticks very poorly to the surface of compressed polystyrene balls.

Technology of laying protective cladding

The procedure for laying out the reinforcing layer can begin almost immediately after blowing in the cracks with foam and drying the putty spots at the installation points of plastic mushrooms on the foam façade. It is clear that before plastering the foam, the surface must be lightly sanded with a grater in order to improve the adhesion of the adhesive mass of the reinforcing layer of plaster to the polystyrene foam.

We glue the mesh onto the foam plastic under the façade plaster accurately and correctly

Immediately about the technique of laying reinforcing mesh. In fact, facade plaster is made from three layers, the weight of the coating on the foam is quite large. The foam can be deformed, and if the mesh is laid incorrectly, cracks will certainly appear on the plaster. Conversely, a well-laid reinforcing sandwich made of glue and mesh is capable of holding even the heaviest types of facade plasters on the surface of the foam plastic.

The most common technique for laying mesh fabric is as follows:

• Cut from a common roll individual canvases mesh height façade walls with a small margin of 5-7 cm;
• An adhesive mass 3-4 mm thick is applied to the surface of the foam, a width slightly larger than the size of the canvas. Sealing of the facade surface begins from top to bottom, immediately applying half the height of the purlin;
• The canvas is laid over the adhesive layer applied to the foam and pressed into the thickness with a wide spatula. It is necessary to press lightly on the façade surface, rather stretch and level the canvas;
• The last stage is laying the adhesive mass over the laid mesh. To glue the second part of the canvas, just roll up the mesh, secure it to the foam with a pin and do all the same operations. The entire mesh must be hidden under the reinforcing adhesive base facade plaster.

The next canvas is laid with an overlap of at least 5 cm, after which it is covered with adhesive material and carefully sanded - leveled with a wide spatula. Upon completion of laying the reinforcing plaster, the facade surface should look absolutely smooth and flat, without protruding defects from the foam.

Finishing corners and slopes with a reinforcing layer

In any house there are quite a lot of problem areas where facade plaster experiences additional stress, these are the corners and slopes of windows. In addition, foam plastic usually “plays” slightly at the corners, so the corner areas have to be strengthened; the easiest way to do this is by laying an additional layer of mesh or installing plastic perforated corners under the façade plaster.

The internal corners of the walls are always reinforced by laying an additional patch. To do this, the reinforcing mesh for plaster is always placed a little further than the corner line, about 7-10 cm. After rubbing the canvas with the adhesive mass, cut out an additional tape from the mesh, apply it to the corner and glue it onto the foam with a double layer of adhesive mass. To ensure that no traces of the reinforcing tape are left on the reinforcing sublayer, which could spoil the decorative finish, the plaster is once again passed over with a wide spatula.

It is extremely important to reinforce the plaster with polystyrene foam on the window slopes. The technique for laying glue on the mesh is similar to the previous case, but there is a nuance - small pieces of fabric, especially for plastering horizontal slopes, must be secured to the insulation with staples.

The outer corners of the façade surface should always be reinforced with perforated corner profiles. The corner edges of the insulation sheets are too weak to maintain the ideal outer corner profile on the façade plaster. The profile for façade plaster is installed in this way. Apply the adhesive mixture to the corner line with a wide spatula in an even strip 15-20 mm wide on both sides. The corner profile is pressed into the plaster, and the side panels are rubbed into the adhesive base with a spatula.

It is best to install the corner profile before plastering the foam; with further adjustment and leveling of the layer of facade plaster, the work will be much easier. Moreover, it is easier to install all the small façade parts before plastering the polystyrene foam than to suffer during the process of applying the plaster.

More detailed instructions on finishing the facade with polystyrene foam and plaster is shown in the video

Laying the leveling layer

The second stage is the alignment of the reinforcing layer with the laid mesh. This must be done, since façade decor on polystyrene foam without leveling will look very uneven. If the surface of the walls is primed for painting or similar facade decoration, the house will lose its entire appearance. A couple of days are allowed to dry the reinforced reinforcing sublayer.

The first operation is to grout the surface of the reinforcing plaster with liquid adhesive mass. Using a wide spatula, apply a leveling sublayer of facade finishing to the walls. The glue is the same, but the consistency is liquid, so as not to load the insulation with additional weight of the finish. After a day, the thin leveling sublayer will dry, and you can proceed to the rough finishing of the facade surface.

No matter how hard the craftsmen try, small marks and even barely visible contours from the foam and mesh remain on the leveling layer, which must be sanded down with sandpaper. Usually they use emery - “weaving”, glued to wooden block. You cannot put off grouting; after a week or two, the rough plaster sublayer will become as hard as concrete. In addition, the risk of abrasive penetration of the finishing material up to the insulation increases.

The detailed process of leveling facade plaster laid over foam insulation is shown in the video

Conclusion

The plaster finish laid over foam plastic is practically no different in appearance from the cement-sand layer on brick or cinder block walls. The last stage, as a rule, involves laying decorative facade finishing. It all depends on the wishes of the owners, for example, in many cases, in order to reduce costs, the leveling plaster sublayer is not covered with decor, but simply covered with a deep penetration primer. You can return to the issue of decorative finishing in a year or two or three. Moreover, it will already be clear how polystyrene foam insulation behaves and whether corrections are needed.

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The constant rise in fuel and energy prices forces home and apartment owners to look for ways to reduce heating costs. The most effective way to insulate buildings, which allows significant savings in fuel consumption for heating, is insulation with polystyrene foam and subsequent plastering of the walls.

Scheme of wall insulation with foam plastic.

Expanded polystyrene is a competitive insulation material that has been widely used in the last decade. This is a gas-filled material consisting of pre-foamed granules dissolved in a polymer mass.

Production of polystyrene foam

The production technology of polystyrene foam involves foaming polystyrene when exposed to steam and sintering pre-foamed granules into large-sized cassettes, followed by cutting them into sheets.

To produce expanded polystyrene, the following components are required:

Scheme of plaster on polystyrene foam.

• foaming polystyrene and other styrene copolymers, granule size 0.4-2.5 mm;
• foaming agents, which are light-boiling hydrocarbons or blowing agents;
• fire retardant;
• dyes and plasticizers;
• saturated water steam with t=110-170°C;
• cold water;
• electricity with voltage 330 V;
• equipment for the production of foam plastic.

Polystyrene foam is formed by steam impact from suspension foaming polystyrene with the addition of a fire retardant to ensure fire safety of the material and has the form of small granules measuring 2-8 mm.

Advantages of the resulting material:

• durability;
• strength;
• moisture resistance;
• light weight of the material;
• low thermal conductivity;
• heat and sound proof;
• low cost;
• availability.

The polystyrene foam production process includes the following steps:

• separation of polystyrene into fractions;
• preliminary foaming of granules;
• drying;
• 12 hour aging of granules in a bunker;
• baking and forming blocks;
• cutting the block into sheets;
• inspection and dispatch of finished sheets to the warehouse.

The quality of polystyrene affects the characteristics of the finished insulation.

The location of the mesh for subsequent overlaps and joints.

The location of the mesh for subsequent overlaps and joints

The longer polystyrene is stored before being used in foam production, the longer it takes to foam and the more difficult it is to achieve the required density of the foam granules.

From the smallest fraction, heavy grades of polystyrene foam are obtained, and the larger fraction of granules is used to produce light grades of insulation. To ensure fire protection characteristics, a fire retardant is used. This is a substance that prevents foam from burning. The quality characteristics of insulation also strongly depend on the temperature and pressure of water vapor. Steam is produced using a steam generator.

Foaming of the granules lasts 5 minutes, while the granules increase in size by 20-50 times.

Extruded polystyrene foam

Scheme of internal and external foam insulation.

An extruder is used to produce extruded foam, the properties and characteristics of which are much better than those of ordinary polystyrene foam. Inside this equipment, polystyrene granules are melted to form a homogeneous viscous mass. A foaming agent is added to the mass and when it is squeezed out of the extruder, it is converted into a liquid substance rather than into individual granules. The material has strong intermolecular bonds, which makes it possible to obtain insulation characterized by great strength.

The integral microstructure of extruded foam consists of a mass of closed cells that are filled with gas. This material has the following characteristics:

• extremely low thermal conductivity, less than 0.03 W/m;
• high strength and durability;
• low moisture absorption;
• good chemical resistance to acids, gasoline, organic solvents;
• When frozen, it retains its thermal insulation properties.

This insulation is widely used for insulating foundations, basements, house walls and facades, floors, and roofs.

Insulation of buildings with polystyrene foam, disadvantages of the material

Polystyrene foam as insulation prevents heat loss, does not allow dampness to enter the house, and creates sound insulation. The walls of buildings can be insulated with polystyrene foam both from the outside and from the inside. When insulating walls from the outside, the foam is secured with glue or mechanically, then it is plastered.

With all the advantages of polystyrene foam, it has some disadvantages that are worth paying attention to:

• fragility of the material if the building insulation technology is not followed;
• can contribute to the formation of mold, if the insulation process is not carried out correctly, the material does not “breathe”.

Scheme for insulating the walls of a corner room.

Often in articles there appears information that when polystyrene foam burns, phosgene gas is formed, which is not true, since this moment Russian enterprises produce foam plastic containing fire-fighting additives - fire retardants. The flammability class of such insulation is G1, which does not support combustion (self-extinguishing). Polystyrene foam, which does not contain fire retardants, has a flammability class of G4; this type of polystyrene foam burns well and can form burning and molten drops. Since polystyrene foam does not contain chlorine, there are no prerequisites for the formation of phosgene during the combustion of polystyrene foam. Like all burning materials, polystyrene foam emits carbon monoxide, an increased concentration of which may pose a danger to human health.

How to properly install insulation?

The use of polystyrene foam for insulating a house requires insulating it under non-combustible plaster. Before plastering the insulation, it must be properly strengthened.

For this you need the following materials and tools:

Floor insulation scheme.

• insulation;
• primer;
• tile adhesive;
• base strip;
• electric drill;
• pobedit drills;
• knife for cutting sheets;
• buckets for preparing primer and glue;
• mixing nozzle;
• disc dowels;
• building level;
• hammer, spatula, roller.

The insulation is attached to the wall with glue or disc dowels, for reliability, both methods can be combined.

Work order:

Scheme of insulating the walls of a house with polystyrene foam.

1. The wall is cleaned of mortar residues, dirt and dust. Prime, if the walls are made of slag concrete, apply the primer 2 times and allow time to dry. The primer prevents the wall material from absorbing moisture from the adhesive.
2. A plinth strip, which is a C-shaped profile made of perforated metal, is attached to the bottom row of slabs. The edge of the plank meets the joint line between the plinth and the wall. The plank is fastened with dowels: there must be at least 3 dowels per 1 m of its length.
3. According to the manufacturer's instructions, prepare tile adhesive and mix it with an electric drill with a mixing attachment.
4. Along the perimeter of the polystyrene foam sheet, glue is applied in the form of a strip with gaps for air release. The glue is applied at a distance of 2-3 cm from the edge of the sheet, and locally in the center, the size of the coated areas is about 10 cm.
5. The long side of the sheet is placed on the base strip and pressed tightly against the wall. The verticality of the glued sheet is checked with a plumb line. The second row is glued with a shift for dressing. The sheets are cut with a long sharp knife.
6. After gluing, the sheets of the first row are secured with disc-shaped dowels. Holes are drilled in concrete wall to a depth of 50 mm, the top of the dowel should be installed flush with the surface of the foam sheet. This is done using a hammer.
7. After attaching the insulation to the wall, apply a layer of glue with a spatula. On the corners of the walls and window openings apply and secure the perforated corners. They protect the edges of the insulation from mechanical stress.
8. A reinforced mesh (mesh size 5 by 5 mm) is applied to the glue layer and rolled with a roller. Another layer of glue is applied to the mesh. Leave the glue to harden and prime the surface with a primer. After the primer has dried, you can begin plastering the walls.

Technology of applying a plaster layer to insulation

Work on plastering polystyrene foam is carried out only in warm weather and without precipitation.

Preparation of plaster solution

Plaster for insulation is purchased in the form of a ready-made dry mixture. The manufacturer's packaging indicates the composition of the plaster and instructions for preparing the working solution. It is added to warm water in small portions, ensuring constant mixing. For mixing, use an electric drill with a special attachment. The plaster is mixed several times with curing periods of several minutes to obtain the required consistency.

How to apply plaster on insulation sheets?

Before plastering the polystyrene foam, a layer of plaster 2-3 mm thick is applied with a spatula to the fixed and primed mesh. Using circular movements along the mesh, it is rubbed and smoothed with a metal spatula. After this, it is left to dry for 24 hours. After drying, the plaster is rubbed with a plastic float with an emery cloth attached to it. At the end, a 3 mm thick facing layer is applied to level the surface. After drying for 24 hours, but no later than 4 days, the layer of plaster is rubbed with a plastic trowel, primed and painted. You can also plaster the surface with a decorative mixture.

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The thermal insulation layer made of polystyrene foam needs reliable protection from the destructive effects of environmental factors. Plaster will adequately cope with this task, the application of which will ensure a long service life of the insulation and improve the thermal insulation of the structure.

The need for plastering foam plastic

Polymer materials are different long term operation. Foam plastic is no exception. Experts conducted tests and subjected the foam to conditions simulating 80 cycles of temperature changes. The results met the technologists' expectations - the foam did not lose its technical characteristics.

How is this possible? After all, many claim that “foamed” insulation is a short-lived material. Indeed, under mechanical influence and direct exposure to ultraviolet rays, the foam dries out and collapses. Using polystyrene foam as thermal insulation, you need to plaster it - this will solve a number of problems:

1. Protection from mechanical damage. Polystyrene foam is a fragile material and can cause a hole if hit. Plaster will protect the insulation from the formation of dents and other damage.
2. The plaster protects the foam from moisture penetration. The insulation does not absorb moisture well and takes a very long time to dry. Prolonged exposure to dampness reduces the thermal insulation properties of the material and makes it more fragile.
3. Foam plaster protects the surface of the material from getting sun rays.
4. Increased fire safety. The plaster will become a kind of shield in the path of fire and prevent the foam from burning.

Foam plastic plastering technology: stages of work execution

To understand the work process, you need to know what stages finishing foam plastic with plaster includes:

1. Preparatory activities: selection of materials, tools and leveling of the base.
2. Preparation of working solution and fastening of reinforcing mesh.
3. Grouting with plaster on the facade mesh.
4. Priming and leveling the plaster layer.
5. Final works: decorative finishing walls

Do-it-yourself foam plaster

We will analyze each stage in detail, dwell on the features of each work process and provide recommendations from specialists on the selection of building materials.

Preparation of tools and materials

To plaster walls using foam plastic you will need the following tools:

• plaster trowel;
• container (bucket or basin) for diluting the working solution;
• drill with mixer;
• painting construction mesh;
• abrasive sandpaper for grouting;
• Master OK;
• putty knife;
• level.

From the materials you need to prepare:

• plaster mixture;
• primer composition;
• decorative plaster.

Special plaster mixtures have been developed for finishing expanded polystyrene. The quality of work and the service life of the thermal insulation will largely depend on the choice of plaster. Foam plastic façade plasters are divided into two main groups:

1. Mineral plasters are affordable. The material is based on cement and sand. This coating is short-lived; 2-3 years after repair work, the plaster layer begins to crack.
2. Acrylic plaster has a number of advantages:
   • high adhesive and protective properties;
   • decorative coating;
   • wide range of colors;
   • possibility of textured finishing (“lamb”, “bark beetle”, “rain”).

Acrylic plaster will cost more than mineral plaster, but such costs are justified by its long service life. The only drawback is that acrylic fades when exposed to UV rays.

Leveling the base

Before applying plaster to polystyrene foam, care must be taken to ensure that the walls are even. The joints between adjacent foam panels should be at the same level. This is easy to determine - just run a rule or a wide spatula along the wall.

Important! Leveling the “rough” surface should not be left for later. It will be almost impossible to correct the defect with a layer of plaster

Particular attention should be paid to the seams between the foam blocks - all areas must be sealed, excess polyurethane foam must be cut off. After leveling, the base must be cleaned of dirt.

Advice. Expanded polystyrene is a fairly smooth material to which glue does not adhere well. It is desirable to increase the adhesion of materials. To do this, just “walk” a needle roller over the surface of the insulation. The working mixture will penetrate very well into the formed small pores

Preparation of the solution

You can purchase ready-made mixtures for foam plastering. The products of Ecomix and Ceresit companies have proven themselves well. On one site construction work It is recommended to use mixtures from the same company. The best option is to choose a universal solution (adhesive plaster for polystyrene foam), which is suitable for attaching insulation to the wall and for arranging a protective layer.

Some companies produce two types of mixtures: separately for fastening insulating boards and separately for protecting them.

To plaster 1 m2 of reinforcing mesh you will need about 4 kg of mixture, and to level 1 m2 of wall - 6 kg

Mixing the working solution must be carried out in accordance with the instructions indicated on the packaging. Experts advise using a slightly thinner solution for gluing the plaster mesh than the manufacturer recommends - this way the mixture will better penetrate all the pores of the insulation.

Installation of plaster mesh

To firmly fix the layer of plaster on the foam, it is necessary to install a mesh. If you apply the plaster directly to the foam, it will crack very quickly or fall off altogether. Strengthening the base with fiberglass mesh will avoid such consequences.

Which mesh should I choose? When working with external insulation, it is better to give preference to denser meshes - it is better to lay plaster on such a reinforcing layer. However, a dense mesh is more difficult to handle corners. The optimal mesh for foam plaster has a density of 130-160 g/m2. It is desirable that the selected material is resistant to alkalis, since it will come into contact with cement.

First of all, start finishing the corners, windows and door slopes. The sequence of installing the mesh at the corners is:

1. Reinforcing mesh for corners - a strip 30 cm wide. The length of the mesh is determined based on the length of the slopes. For laying on the corners of the house, the mesh is cut into strips about 1 meter long.
2. Make a bend in the middle of the mesh.
3. Apply the solution to the wall with a wide spatula. The length of the strip is equal to the mesh cut, and the width is 10 cm larger than the size of the piece (you need to leave 5 cm on both sides for overlap).
4. Place the mesh on the corner and smooth it out with a spatula. The direction of movement of the spatula is from top to bottom and from the center to the edge. The mesh should be completely immersed in the solution.

Installation of the mesh on the walls is carried out in the following sequence:

1. Cut the “plaster” mesh into pieces. The length of each cut is no more than 1 meter.
2. Fastening is carried out sequentially in small parts, since the mixture dries quickly enough. The dimensions of each plot are about 90 cm by 1 meter. The remaining 10 cm will be needed for gluing the joints.
3. Apply the mixture to one area with a spatula.
4. Apply the mesh to the wall, press and level with a spatula. Using smoothing movements, fix the mesh. If the mesh is not completely immersed in the mixture, the solution can be applied to a spatula and re-leveled.
5. This kind of work must be done with each section of the wall, moving to the side. The mesh is installed overlapping.

Grouting on façade mesh

The reinforcing mesh glued into the plaster solution must be rubbed using an emery cloth or a plastic trowel. This process begins after complete drying. universal mixture. In hot weather, the plaster dries within 2-3 hours, and in cloudy weather - at least a day.

Grouting should be done in a circular motion in a counterclockwise direction. If undried plaster gets on the sandpaper, the cloth must be replaced.

Primer and leveling

Next stage external plaster for foam plastic - applying a leveling layer and priming the surface.

Finishing the walls

The final stage is decorative finishing. For external work, special facade plasters have been developed that are resistant to temperature changes and climate changes. The properties of facade plaster largely depend on the type of binder and the presence of additional components. For work, mineral, acrylic and silicate plaster is used.

Sequence of applying decorative plaster:

1. Prepare a working solution ( mineral mixture). Mix the finished plaster (acrylic composition) thoroughly.
2. Applying plaster. At this stage, it is necessary to plan the structure of the future finishing - the set of tools and the technology used will depend on this. The thickness of one layer should not exceed 40 mm, and the next one should be applied after the previous one has dried.
3. Grout. This stage is started when the layer of plaster is half dry, can be adjusted, and at the same time is already fixed on the surface. The special structure of the facade is formed using a roller of a special configuration.

Important! Application of façade plaster should be carried out under favorable weather conditions:

• optimal temperature 5-25°C;
• air humidity - no more than 65-70%;
• no strong wind.

Bark beetle - plaster for polystyrene foam: application technology

Foam plaster: video

Are you tired of “heating the street” every winter and overpaying for heating?

Then it's time to start insulating the house. Most affordable way- this is to line it with foam plastic or penoplex, and then plaster it to protect the insulation and externally improve the house. Read about how to do polystyrene plaster with your own hands in this article.

Let's start with why many people choose foam plastic as insulation. The reason is simple: low price, light weight that does not create a load on the foundation, and ease of installation.

But this material is not at all durable; it is destroyed by exposure to ultraviolet rays, atmospheric moisture and temperature changes. And it doesn't look very good. Therefore, its external finishing is needed, which is often used as plaster.

Note. A relative of polystyrene foam, penoplex, has the best technical and operational characteristics. In addition, mice and other rodents do not like it. But it costs more, and still requires finishing.

Now about what the plaster for polystyrene foam should be like:

• Since we are talking about exterior finishing, it must be durable, water- and frost-resistant. Therefore, you can forget about gypsum-based compositions; only cement mixtures are suitable.
• And not those that are made right on site from cement, sand and water, but special ready-made dry mixtures designed specifically for such work. In addition to the main components, they include additives that improve the adhesion of the solution to the base and improve the quality of the finished surface.

• If you have already watched a video on how to plaster polystyrene foam, you probably noticed that a reinforcing mesh is first glued onto it, and only then the surface is leveled. For these works, different mixtures are produced - adhesive and leveling.
• But some manufacturers also have universal formulations in their assortment that can be used at any stage.

What to choose is up to you, but remember that it is better to use products from the same manufacturer, since different brands may differ not only in color and structure, but also in composition, and interact poorly with each other.

For reference. To determine the amount of material, use the following values: 10 kg of universal mixture or 4 kg of adhesive and 6 kg of plaster for each square meter walls.

Rules for plastering polystyrene foam surfaces

You won't be able to complete all the work in one day. And not because of a lack of experience, but simply because you will have to strictly adhere to the technology.

The instructions require arranging intervals between the main stages of work, which, depending on the temperature and humidity of the surrounding air, can range from several hours to several days.

If you want to know how to plaster on foam plastic correctly, check out detailed description these stages.

Preparation of the solution

This stage cannot be called the first, but rather periodically repeated. The fact is that styrofoam plaster, like any other cement-based mixture, loses moisture quite quickly and thickens. It cannot be diluted, as lumps will inevitably remain, and a thick solution is difficult to work with, and it will also lose its adhesive properties.

Therefore, it is prepared in small portions immediately before use. The preparation itself consists of mixing the dry mixture with water and thoroughly mixing with a drill with a mixer attachment. The proportions are indicated by the manufacturer on the packaging; read these recommendations carefully before you start mixing.

Advice. Before each mixing, thoroughly clean the container and mixer from the frozen solution. It is better to keep the nozzle in a bucket of water while working.

Installation of reinforcing mesh

Polystyrene foam and penoplex have a surface that is not capable of high-quality adhesion. In other words, the solution does not stick well to them: it either falls off over time or becomes covered with cracks.

Therefore, before plastering the foam, the surface must be reinforced with a special mesh, which will improve adhesion and give the finishing layer greater strength.

When choosing a plaster mesh, give preference to a material with the following characteristics:

• Alkali resistance. Cement mortar– this is a rather aggressive substance with an alkaline reaction, capable of destroying materials that are unstable to it;
• Density about 140-160 g/m2. A less dense mesh will not provide high quality adhesion of the plaster to the polystyrene foam base, and a denser mesh will be difficult to work with, especially when reinforcing corners.

This is where do-it-yourself polystyrene plastering begins - with attaching mesh strips to the outer corners of the house, door and window slopes and other protruding structural elements.

This is done in this order:

• The mesh is cut into strips about 30 cm wide and long, equal to length corner.

Advice. Since it is inconvenient to work with very large sections, it is advisable to make strips no longer than two meters and glue them overlapping.

• The strip is folded in half lengthwise and tightly compressed along the fold to create a stiffening rib.
• Having prepared the required number of strips, mix the solution and immediately begin installation.
• Using a spatula, apply the mixture to both sides of the corner to a width of 20 cm in a layer of about 3 mm, attach the prepared strip to it and press it into the solution, working with the spatula from the corner down and to the side on both sides.

In this way, all corners are covered, after which the mesh is mounted on the plane.

Due to the rapid drying of the solution, work is carried out in small areas:

• A piece of approximately the same length is cut from a roll 1 meter wide;
• A section of the wall measuring 0.9 by 0.9 meters is covered with an adhesive or universal mixture (10 cm on both sides is left for gluing the joints when installing the next strip);
• As with the corners, the mesh is applied to the fresh mortar and pressed into it using smoothing movements of a wide spatula from the center to the edges;
• Under the pressure of the spatula, the mesh is immersed in the solution. If it is not enough, an additional small portion of the mixture is taken onto the spatula and applied on top of the canvas;

• Each subsequent strip is laid with an overlap, the joints are processed especially carefully;
• The last lane adjacent to opposite corner, if necessary, cut to width.

After fixing the mesh over the entire surface, let the solution dry. In dry and warm weather this will take 4-8 hours, in damp and cool weather - 1-2 days.

You can assess the degree of drying visually and by touch - the surface should be the same color, without dark spots and not leave a feeling of moisture on the palm.

After this, it must be rubbed down by securing sandpaper to a construction float. The work is done in a circular motion with little force. Your task is to remove sagging, drips, and frozen splashes of plaster.

It is important. If the surface is left to dry for several days, the solution will gain such strength that it will take a lot of effort to grout. Therefore, plan your time so that you complete this step on time.

Applying a leveling layer

If you managed to glue the mesh with high quality, then this stage will not cause you any difficulties.

Before you get started, watch the video on how to plaster polystyrene foam and read our recommendations:

• Prepare a solution from a leveling or universal mixture in such an amount that you can use it in 30 minutes;
• Take two spatulas: a narrow one for scooping up the solution and transferring it to the working tool, and a wide one for applying and smoothing;
• Having placed a small amount of the mixture on a working spatula, apply it to the wall at a slight angle and with a smooth, confident movement, pull it to the side and down or up so that the solution is distributed over the surface in a layer of 3-4 mm;

• Collect the remaining mortar on the working spatula with a narrow auxiliary one, transfer it again to the blade and distribute it along the wall with a movement across the applied layer;
• Start work from the top corner, gradually moving to the side and down until the entire surface is covered with a thin layer of plaster.

If, before plastering the foam, you have thoroughly sanded the previous layer, then the work will be easy. Try to apply the solution so that the joints between two portions do not coincide with the joints of the reinforcing mesh. This will make the seams invisible and avoid cracks.

Then again follow the troweling work, which is carried out at the same time interval and according to the same principle as after installing the mesh. Except that they require more attention and care to achieve an even and smooth surface.

Decorative plaster

One of the most common methods of exterior finishing of private houses is decorative plaster. In our case, after insulation with foam plastic, this method can be used to decorate any buildings, even wooden ones.

But before you start applying bark beetle plaster to polystyrene foam protected by ordinary plaster with reinforcing mesh, the surface must be primed (see Priming walls and everything on this issue). This work is low-cost both in terms of costs and time, but invaluable in benefits.

So:

• Firstly, the primer increases the adhesion of materials, and the decorative finish will stick to the walls better;
• Secondly, by reducing the absorbency of the base, you will be able to save on expensive finishing material;
• Thirdly, when using a primer with antiseptic properties, you will avoid the appearance of mold on the walls.

Therefore, do not neglect this stage. Apply the primer to the walls with a roller or brush, creating a continuous coat and avoiding drips, and allow it to soak in and dry.

Decorative plaster is applied in the usual way, but until the layer on the treated area has dried, it is given the desired texture. This is done using a grater, decorative roller or other devices. You can learn more about this from our other materials on this topic.

Painting of the surface begins after the textured decorative layer has dried.

Conclusion

We tried to tell you as much as possible about plastering walls using polystyrene foam. If something remains unclear, the video in this article will help you figure it out.

Now, even if you do not decide to insulate the house yourself and finish it in this way, you will know how such work should be done and will be able to control its implementation by contractors.

The facades of many houses are insulated using polystyrene foam. However, in order for such insulation to serve as long as possible, it is necessary to plaster the facade. Foam plastic does not tolerate various external influences in the form of wind, sunlight, moisture, etc. And plaster can significantly extend the service life of foam plastic and maintain the original thermal insulation characteristics of the facade for as long as possible.

Scheme of a facade insulated with foam plastic, finished with plaster.

Preparing tools and mixture for plastering

The facade will be plastered using the following tools and materials:

For high-quality plastering you will need special tools.

1. Containers for preparing the working mixture.
2. Construction mixer.
3. Painting construction mesh.
4. Corner.
5. Sandpaper.
6. Gypsum plaster mixture.
7. Scissors.
8. Primers.
9. Spatula.
10. Paint rollers.

A facade with foam insulation can be plastered using various mixtures for finishing polystyrene materials. Some manufacturers offer one for styrofoam plastering universal composition, others are a composition of two mixtures, one of which will be used for gluing the painting mesh to the surface of the foam, and the second part will be used for simultaneously gluing the mesh to the surface to be treated and further creating a protective layer.

The mixture is prepared according to the instructions, which can be found on the back of the package.

It is best to find and buy a universal mixture. With its help, you can glue a painting mesh to the surface to be treated and process the foam with the highest quality possible. This type of plaster is very economical. In order to glue the mesh to the facade, you will have to spend about 4 kg of plaster per 1 m2 of surface. Leveling the walls will take about 6 kg of plaster per 1 m2 of area.

When preparing the plaster, you must strictly follow the instructions given on the packaging, because... They may vary for different mixtures. After the plaster is ready, you can use it to begin gluing the mesh to the facade. It is most convenient to glue the painting mesh to the facade if the plaster has the consistency of sour cream.

Step-by-step instructions for gluing plaster mesh to the facade

In order for the plaster to adhere well to the foam, it is necessary to use a special mesh.

In order for the penoplex plaster to adhere well, it is necessary to use a special painting mesh. A mesh with a density of about 160 g/m2 is best suited. The greater the density of the mesh for facade work, the more even the resulting plaster on foam plastic will be.

First, the corners are glued, including the slopes of door and window openings. Take a plaster painting mesh and cut a piece of it 30 cm wide and a length equal to the length of the slope, or, if you are gluing the corner of a house, about 1 m. Bend the resulting strip in the middle so that even after removing the force, the “edge” does not disappear. Take a spatula and apply the pre-prepared mixture to the corners and slopes to be treated. Apply it in a layer of 2-3 mm. Apply the mesh, press with a spatula and smooth out thoroughly. Move from the corner down and to the side. Glue all the corners, being sure to leave the unglued parts for future gluing of the joints. After this, you can start gluing the mesh on the plane.

To do this, cut the mesh into pieces. Pieces of 1x1 m will be enough. Making them larger does not make sense, because... the mixture dries very quickly, and you may simply not have time to glue it. Apply the universal mixture to the surface using a spatula. Make strips 100 cm long and about 90 cm wide. 5 cm from the edges will later be used for gluing the joints. Apply this mixture in a layer of about 3 mm.

Laying the mesh fastening on the wall.

Place the mesh against the wall and smooth it using the same spatula. Gently smooth from the middle and top to bottom. Do everything so that the mesh is almost pressed into the applied mixture. While smoothing, you can additionally apply a small amount of mixture to the spatula to cover the entire mesh. Finish with this vertical strip, move to the side and glue the next strip. Pieces of mesh are glued overlapping. The joints of the resulting strips must be carefully and neatly taped. The joints at the corners are also overlapped.

If you do not leave un-glued sections of the mesh, but simply glue the seams overlapping, the resulting joints will be very rough and noticeable even after applying a fine finish. The glued mesh must be rubbed down. To do this, use a plastic grater with sandpaper. Grouting is done using the dried mixture. In warm weather, the universal mixture dries quite quickly - usually a few hours are enough. If it’s cloudy and cool outside, it’s better to give it a day. Rub the mixture with some force, making circular movements in a counterclockwise direction. If some of the undried mixture gets into the sanding cloth during work, it will need to be replaced.

Applying and grouting the leveling layer

At the next stage of work it will be necessary to apply a leveling layer. It is applied using the universal mixture you are already familiar with, with which you created the protective layer.

The leveling layer is applied in the following order:

The plaster is applied to the wall using a wide spatula using even movements.

1. You take a wide spatula (at least 35 cm) and, using a smaller spatula, apply the leveling mixture on it.
2. After this, apply the leveling mixture to the surface using even movements. On average, the thickness of this layer is about 3 mm. The final value depends on how well the mesh was grouted.
3. Apply the leveling layer in small sections, trying to make the joints as far as possible from the joints of the painting mesh.

The leveling layer is rubbed in the same way as the plaster mesh. Be sure to take into account the fact that you can start grouting the leveling layer at least a day later and at a maximum 4 days after its application. If you leave the leveling layer for a longer period of time, it will “over-set”, and you will have to make very significant efforts during grouting.

The leveling layer is rubbed until the most even surface is obtained.

The finishing touch will be applied to it, for example, textured or decorative plaster. The order of their application in the case of a facade finished with foam plastic does not differ significantly. Choose the option you like best and get to work.

Procedure for applying primer and plaster

Before applying the final finish, the surface must be primed. A composition with quartz grains is best suited for plaster. Use a short-nap roller to apply the primer. Do everything carefully, leaving no drips if possible. After treating the entire surface, you can begin finishing facade on foam plastic.

When applying plaster to a previously leveled and primed base, you must adhere to a certain sequence. First, take a putty knife and apply a base coat of plaster. Make sure that the layer has a uniform thickness over the entire area of ​​the surface being treated. When choosing the thickness of the layer, it is necessary to focus on the size of the mineral grains present in the mixture. The more grain, the thicker the layer should be.

Apply a base coat to a certain area of ​​the surface, and then take a large-pore sponge, grater or spatula and begin creating a decorative texture. Treat the entire surface in this order and leave it to dry. Wait until the plaster is completely dry. If you wish, you can paint it. It is best to use paints specially designed for facade work. The surface can also be coated with a layer of simple colorless protective varnish.

This is the order in which styrofoam plastering is performed. If you are planning or have already insulated the facade of your house using polystyrene foam boards, now you know how to plaster them yourself and will be able to do this work without involving third-party craftsmen and saving money. Happy work!

May 15, 2018
Specialization: master in the construction of plasterboard structures, finishing works and styling floor coverings. Installation of door and window units, finishing of facades, installation of electrical, plumbing and heating - I can give detailed advice on all types of work.

If you need to plaster walls insulated with foam plastic, then this review will tell you how to properly organize the work process and what you will need for this. The work is not difficult and can be done with your own hands if you are ready to understand the technology and master plastering work.

Work technology

With all its advantages, foam plastic needs additional protection, since the material is quite fragile and does not tolerate ultraviolet radiation from the sun. The simplest solution is to plaster the surface; the work consists of several stages:

• preparation of materials and tools;
• leveling the base and preparing it for finishing;
• laying reinforcing mesh and applying the first layer of plaster;
• grouting the surface and applying primer;
• application of the second layer and decorative finishing of the walls.

Let's look at each stage in more detail.

Tools and materials

First, let's figure out how to plaster polystyrene foam. There are several mixture options:

Illustration	Description
	Cement facade plaster. The packaging must indicate that the composition is suitable for outdoor use. This option is characterized by low cost and good strength characteristics. Composition on mineral based suitable for the first layer; for the second, the options described below are used.
	Compositions on acrylic base . A good solution that combines average cost and good performance. Most often, the compositions are sold ready-made and may have different fillers that determine the structure. Acrylic plaster can be tinted to the desired color, which is also important.
	Silicate-based mixtures- are moisture resistant and have good vapor permeability. At the same time, the cost is not very high, the option is available to a wide range of buyers.
	Silicone plasters- the most modern option, characterized by durability and excellent performance properties. They have one big drawback - high cost. At the same time, decorative plaster is very durable, as it creates an elastic layer that is resistant to cracking.

In addition to plaster, you will need other materials:

Illustration	Description
	Facade mesh. When choosing a plaster mesh, pay attention to the following aspects: Material Density. It should be at least 160 grams per square meter, only this option will provide the required surface hardness; Weaving quality. The cells must be smooth - without asymmetry or curvature.
	Facade primer. The composition is used to strengthen the first plaster layer and creates an additional barrier to moisture penetration.

The following tool is used for work:

• Plaster grater. A special tool allows you to quickly and efficiently smooth the surface.
• Container for mixing the solution. If you have a ready-made composition, then you don’t need to use additional containers.
• Drill with mixer attachment. Necessary for preparing a high-quality solution.
• Needle roller. Used to prepare surfaces for plastering.

• Spatula or steel float for applying the composition. It all depends on your preferences; for some it is convenient to work with a grater, and for others with a wide spatula.

Leveling the base and preparing for finishing

This stage is carried out after attaching the insulation sheets, which are best glued to a special compound and additionally fixed with special dowels for thermal insulation. Surface preparation is as follows:

• Checking the plane of the walls. Run your hand along the joints and you will see raised areas. Excess material is removed either with a special plane, or with a spatula or other available device.
• If the dowel heads protrude, they need to be deepened. Most often, careful tapping with a hammer is enough; ideally, the fasteners are located just below the plane of the wall.

• If there are gaps between the slabs, they must be sealed. Best suited for work polyurethane foam or special glue for thermal insulation. The composition is carefully distributed over the voids to fill them and make the surface monolithic.

Don't worry if excess foam comes out; after drying, you can easily cut it off with a construction knife.

• If foam adhesive protrudes from the joints, it should be removed. For this, any available device is used.
• Lastly, you need to go over the surface with a needle roller. It will make many small depressions on the smooth foam and the plaster will stick much better.

Laying the mesh and applying the first layer of plaster

This part of the work consists of the following actions:

Illustration	Description
	Plaster mortar being prepared. It is best to carry out the work using a drill with a mixer; this will save you time and help you achieve best quality stirring.
	Apply a layer of plaster using a notched trowel. The height of the teeth should be 4-5 mm, the composition is evenly distributed in a vertical strip about a meter wide - according to the size of the façade mesh. Usage of this instrument It greatly simplifies the work, since you will accurately apply an even layer and remove all excess from the surface.
	Mesh is glued. To do this, cut out a piece whose length is slightly greater than the height of the wall; the excess will be cut off later, and you will not have to precisely align the piece. The strip is pressed at the top and pressed into the surface with a grater or spatula so that the mesh is not visible. If necessary, you can put a little more plaster on top. Work is carried out from top to bottom until the entire strip is hidden by the solution. Subsequent rows are placed with an overlap of 50-65 mm at the joints, and the process is repeated.
	The surface is left to dry. In hot weather, 2-3 hours will be enough, in cool weather - 4-6. It’s also not a good idea to over-dry the walls, as they will scuff much worse.

Grouting the surface and applying primer

This stage consists of the following work:

• The surface is rubbed. All externally plastered walls are leveled using a polyurethane float, which must be worked in a circular motion. Try to leave a minimum of unevenness and make the base smooth and uniform. If you find dry areas somewhere, you can lightly moisten them using a household sprayer.

If the facade mesh appears on the surface in some places, it’s okay, a decorative layer will still be applied on top.

• Primer is applied. If you moistened the surface during the grouting process, wait until it dries completely. The soil is distributed over the entire leveling layer and strengthens it, and also improves the adhesion of the next layer. If the cladding is done with clinker or tiles, then a primer is also required.

Applying the finishing layer

There are two options for carrying out the work:

• The final finishing is done with the same plaster as the leveling layer.. In this case, you need to distribute the solution thinly to level the surface and reduce the amount of work during finishing grouting. Subsequently, the walls are rubbed down again. After which you can apply another layer of primer and paint the facade.

• If a decorative composition is applied, the application technology depends on the type of mixture. The bark beetle is spread with a plastic grater; the structure depends on the direction of its movement. Other options are distributed in their own way, the main thing is to understand all the nuances of application in advance. At the end, coloring may be required, but if the composition contained pigment, then this is not required.

Conclusion

Now you know what materials need to be used when plastering foam plastic and what stages the work process consists of. The video will tell and clearly show some important points, and if you have questions on the topic, write them in the comments.