The procedure for plastering polystyrene foam. How to plaster polystyrene foam: tips for choosing mixtures and step-by-step technology of work How to properly plaster polystyrene foam from the outside

Insulating the walls of a house with polystyrene foam was, is and will be one of the most popular types thermal insulation. The popularity of polystyrene foam is due to its low price - insulating even a large house from the outside is a completely feasible task for the family budget. The task can be considered completed if the foam has been plastered and puttyed, either by craftsmen or with your own hands.

Is it possible to plaster penoplex and polystyrene foam - mistakes and misconceptions

Polystyrene foam, like other polymeric materials, has a very long decomposition period. Scientists talk about successful testing of slabs of this material under conditions simulating 80 cycles of temperature changes. How can this be, you ask? After all, everyone around is talking about the fragility of polystyrene foam. This statement is only partially true - polystyrene foam becomes short-lived when exposed to direct ultraviolet radiation (sun rays) and mechanical influence. That is, if you decide to insulate the facade with foam plastic, you should take care to protect the material from these two factors.

As they say experienced craftsmen, if you plaster the foam and carry out timely renovation work On average, the service life of such a facade can be extended to 20 years. And the foam plastic for insulation and plaster must be special - grades PSB-S-15, PSB-S-25. The second misconception, popular among builders, is that polystyrene foam is flammable. And again, the statement only partially corresponds to the truth - of course, polystyrene foam is flammable, but its ignition temperature is almost 2 times higher than that of the same wood, and during combustion it releases two to three times less thermal energy.

That is, in the event of a possible fire, polystyrene foam, as this material is more correctly called, gives a minimal increase in the temperature of the walls, and therefore, it is more than suitable for inside and outside. If the technology is followed in the production of insulation boards, as well as their installation, they become significantly safer than other popular materials involved in repairs and construction.

Another common myth concerns the lack of benefit from façade insulation and the lack of significant heat gain. Indeed, plastering walls over previously installed polystyrene foam will not make the house warmer by itself, but heating it will be much easier - insulated walls retain heat inside the house 30% better than without insulation. Thanks to saving electricity and fuel resources, wall insulation pays for itself in an average of 5 years, after which you will pay significantly less for heating for at least 15 years.

Protective layer for foam plastic – puttying and plastering

The most popular way to protect polystyrene foam from exposure environment– plastering. The essence of the process is to create a reinforcing and protective layer that can resist mechanical damage and completely neutralize the ingress of ultraviolet radiation.

The entire process of plastering polystyrene foam is as follows:

special plaster mixtures are prepared (ordinary plaster is not suitable here);
a reinforcing mesh is fixed on top of the polystyrene foam;
the first layer of plaster is applied;
the walls are leveled;
final grouting;
priming the surface for decorative plaster;
finishing with decorative plaster (bark beetle, mosaic).

It would seem that it is quite easy to figure out how to plaster and rub foam plastic, and this operation can be done either with your own hands or by hiring a construction team at a reasonable price. In both cases, do not make basic mistakes - buy only specialized mixtures for polystyrene foam, do not skimp on. If you are determined to do all the work yourself, watch the training videos.

Today, the most trusted manufacturers of plaster for foam plastic and similar materials are the companies Ecomix and Ceresit. It is very important that the putty used for foam plastic at different times is from only one manufacturer. On average, about 4 kg of mixture is consumed per square meter in the process of grouting the mesh, and up to 6 kg for the main layer of plaster. You don’t have to count the final grouting layer - just take mixtures with a margin of 8–10%.

Plastering technology - we work on polystyrene foam with our own hands

Working with polystyrene foam is a pleasure - even slabs of expanded polystyrene, maintained in strictly defined parameters, are installed in a matter of hours. But plastering the walls will take longer. We start everything by mixing the mixture - we do this strictly according to the instructions from the manufacturer. True, in practice, the mixture for gluing the reinforcing mesh should be made somewhat thinner - in this case it penetrates better into all the cells.

And for the grout layer, the consistency should be liquid and fluid, which is not written in the instructions.

Plaster mesh is a mandatory attribute when plastering polystyrene foam. You can find out what it looks like from the video. It is thanks to this element that the composition will adhere to polystyrene foam. Since the mixture contains cement, the mesh should be selected from alkali-resistant ones. The denser the mesh you choose, the easier it will be to plaster with your own hands. Glue the plaster mesh using a universal mixture, starting from the corners and slopes.

For ease of work, cut strips of the required length (we focus on the height of the wall, leave a small margin) and a width of 30–60 cm. Gluing begins from top to bottom, from the top edge of the mesh - holding it with one hand, with the other, using a spatula, apply the solution in a solid line along the entire edge . Layer thickness is about 5 mm. As soon as the mixture sets, we begin to secure the strip along the entire width, moving from top to bottom.

Keep in mind that it is correct to install the adjacent strip with an overlap of at least a centimeter, so you should always leave a space free of plaster on the previous strip, as shown in the video. This is exactly how we move gradually along the entire perimeter of the wall and secure the reinforcing mesh. On level places without corners or slopes, you can cut the material into pieces up to 1 meter wide, no more. You simply won’t have time to glue more, since the gluing mixture dries very quickly.

The next stage is grouting the mesh with your own hands. To do this you will need a plastic grater with an emery cloth. The procedure is carried out only on a dried layer of plaster into which the mesh has been glued. In hot summer weather, it is enough to wait a few hours, but in damp, cloudy weather - a day. Rubbing should be done in a circular motion, applying little effort. From time to time, the sanding cloth should be knocked out of dust and replaced with a new one.

Be sure to wear safety glasses and a respirator. After completing this stage, we proceed to applying the main leveling layer. It will require the same plaster mixture and two spatulas with wide and narrow blades. Using a small spatula, apply the mixture onto a wider one and spread it over the surface with wide movements. Layer thickness – 3–5 mm. To get started, watch videos with examples of work and practice small area. According to the technology, the joints of the sections of the leveling layer should be located as far as possible from the joints of the mesh.

Then all that remains is to wait until the leveling plaster dries and rub it in according to the same principles as the plaster mesh. It is important not to delay this - you have up to 4 days. Then, every day the material will become stronger, and a lot of effort will have to be spent on grouting.

It is imperative to apply a finishing decorative finish to the prepared (primed) wall surface, for example, apply it yourself textured plaster under a fur coat or using the “bark beetle” technology. Many people do not consider it necessary to plaster the walls again, but thanks to this layer, the insulation of the facade will last much longer.

Thermal insulation materials such as polystyrene foam are gaining more and more popularity every year. Expanded polystyrene boards are made of small white porous cells glued together. Such materials consist of approximately 98% air. Each cell is isolated from the rest, so the thermal insulation properties of the foam are very high. Specially made slabs are mainly used for external insulation of private houses.

Such useful material often used for finishing kiosks, refrigeration units, and also for protecting electrical wiring laid underground. Finishing the facade with plaster after insulation is carried out using a specially developed wet or ventilated facade technology.

The main advantages of polystyrene foam

There are several reasons why modern homeowners choose foam plastic finishing to insulate the outside walls of their homes:

Insulation from the outside helps to remove the dew point beyond the wall structure. A dry building will not be susceptible to fungus and mold and, as a result, will last longer;
Useful space in the room is not lost;
Structures built from reinforced concrete, brick or, for example, stone, contribute to the accumulation of heat. The cold during frosts begins to penetrate into such houses much later;
The relative density of foam has its advantages. After reinforcement, this material serves as a fairly reliable basis for finishing with plaster and subsequent painting.

Easy to install and accessible

Experienced experts say that you can’t think of a better way to ensure thermal insulation of a house than insulation with foam plastic, especially if after this you plan to finish the outside walls with plaster and subsequent painting. Materials such as polystyrene foam, among many others, stand out for their low cost, low thermal conductivity, high service life, lightness, simplicity and ease of processing. Each owner of a private home has the opportunity to significantly save financial costs by choosing such technology.

Using polystyrene foam, the building will be well protected from moisture penetration and the possible formation of mold, mildew, and unpleasant odors. Such building materials can be used for both exterior and indoor installation. The second option is suitable for those who have a fairly large area of rooms in their home. In the future, the insulating materials are covered with plasterboard and painting or wallpapering, etc. is possible.

For external insulation, polystyrene foam is glued or fixed using special disc-shaped dowels. During the work process, experts recommend paying sufficient attention to isolation from ignition sources. For guard thermal insulation material against external influences, many products available on the market are used:

Applying plaster and subsequent painting of walls;
Brick lining;
Ceramic fireproof tiles.

It must be remembered that polystyrene foam is one of the most flammable substances and requires careful handling.

It should be noted that insulating the walls of a house with polystyrene foam and finishing the facades with plaster is most often done in the southern regions of the country, where summers are very hot and long. Therefore, there is a need to reduce heating costs in winter and air conditioning costs when the outside temperature is high.

Let's understand the main types of slabs

Most often, grade C-25 is used to insulate the walls of a house with polystyrene foam. The density of such material is 25 kg/m3, but such polystyrene foam has too high a thermal conductivity index.

Also, a lot depends on the cost of the slabs. The price for the S-25 brand starts from 1900 rubles, and the S-35 material is twice as expensive.
The climatic conditions of a particular region largely determine required thickness material. For Krasnodar region For example, insulating the walls of a house with polystyrene foam from the outside is carried out using a material whose minimum thickness is 40-50 mm. In Yakutia or the Far East, finishing is done with slabs from 150 mm.

Possibility of using polystyrene foam as insulation for wooden walls

Technically, it is possible to insulate wooden walls at home with polystyrene foam outside, but this is not recommended, since vapor permeability will deteriorate.
The main task of specialists in such cases will always be to ensure correct vapor permeability. This indicator should decrease from external to internal walls. If this is not observed, moisture will accumulate inside the structure, which will inevitably lead to rotting over time.

Experts give the following recommendations:

Polystyrene foam can be installed not on the wall, but on a pre-installed sheathing, which helps additional ventilation. To perform the technology correctly, it is necessary to install special slats, the thickness of which is at least 25 mm. In this case, the recommended distance between them corresponds to a maximum of 25 cm. Subsequent insulation of the facade with foam plastic from the outside is carried out only using umbrella dowels.
The optimal finishing option is considered to be the method of installing insulation between the profiles. From the outside, such a façade is sheathed with siding or metal plates if the technology for installing a ventilated façade is used.

The order of finishing work

First of all, it is necessary to level the wall as much as possible. This reduces the likelihood of thermal insulation damage due to mechanical stress. It is also recommended to pre-clean the wall surface if the facade was previously painted or is slightly crumbling. To do this, you can use an ordinary spatula or brush.

Installation of insulation is carried out in this way:

The starting profile is mounted on the lower edge of the future facade;
The foam is installed from the bottom up and fixed with special glue and umbrella dowels. A sufficient number of disc dowels is determined at a minimum of 5 pieces per sheet.
Every new row polystyrene foam boards are laid out so that vertical seams didn't match.
The reinforcement technology is as follows: Horizontal strips of reinforcing mesh are glued to each seam with an overlap of approximately 5-10 cm, after which they are treated with an adhesive composition. It is recommended to use a wide spatula. Any irregularities are removed with a special grater after drying.
To secure the thermal insulation at the corners, it is necessary to use special perforated devices. The fragile foam will thus be reliably protected from mechanical damage.
At the stage finishing The outside of the façade uses putty or special structural plaster followed by painting.

Preparation of the mixture for plastering

For finishing foam plastic with plaster, the most different compositions. Building materials made by different manufacturers, it is not recommended to use when finishing facades.

Some manufacturers produce products suitable for working with polystyrene boards, containing only one mixture. To apply a plaster wall to thermal insulation and perform subsequent finishing work, it is recommended to use a universal mixture.

For gluing the mesh, approximately 4 kg of mixture per m is used, and for final finishing façade requires up to 6 kg/m. During the mixing process, you must follow all the instructions provided by the manufacturer on the packaging. Many years of experience of specialists in the construction field shows that it is much more convenient to prepare a mixture whose consistency should not be as thick as the manufacturer recommends. For a leveling layer, the plaster composition must spread over the spatula.

Having understood the technology for making the mixture, you can begin to glue the mesh to securely fix the plaster on the foam.

Features of proper plaster

When applying plaster, it is recommended to use a special trowel made of foam plastic or wood. Decoration Materials pressed against the wall and rubbed in a circular motion. The plaster must be well fixed to the smooth surface of the polystyrene foam boards. For this purpose, a special mesh is most often used, designed for finishing facade works, the density of which is 140-160 g/m. The uniformity of the applied plaster layer is largely determined by the density of the mesh. But this material is not suitable for bending. You need to start working from the corners, doorways, slopes. After this, the grouting procedure is performed using a special plastic trowel with a fairly reliable cloth, but only after the adhesive has dried.

A leveling compound is applied to a spatula, the width of which is at least 350 mm;
All this mass is evenly and carefully applied to the wall. The possible thickness of the applied layer directly depends on the quality of the pre-grouted plaster mesh;
The leveling layer is applied in several sections, the places of contact of which should not coincide with the joints of the plaster mesh.

Silicone, silicate, mineral, or acrylic plaster. The quality of some materials allows them to be painted in various colors. It should be noted that the silicone lining can be cleaned with rainwater.

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 in order to protect such cladding from the harmful effects of the environment, you need to choose for it suitable covering. The best option here is façade plaster, since it does not require much expense, 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 be easily 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.

Regular cement-sand mixture meets these requirements only partially, 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 are in particular 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	Compound universal purpose on cement based. 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 mixture polymer based, 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 is easy to accept the required form 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 you use different plasters on the same plane, 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 cleaned sandpaper joints. The surface must be smooth, without protrusions or depressions, and free of dust. If the foam boards are too smooth, experienced builders It is recommended to lightly sand them or roll 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 a ready-made composition is used, it just needs to be mixed in case the particles settle.

Step 2. Corners, slopes and areas with complex configurations are finished first. Designed for this perforated corners with fiberglass mesh attached to them.

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 all corner zones have been processed, 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. Plaster mortar 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 on separate 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 skin is selected depending on the type 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

Finish 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. The presence of moisture, dust, and greasy stains on the 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 bills for utilities every year. Choosing between a range of materials for external insulation, are increasingly focusing on polystyrene foam. This building 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 settled on foam plastic, or its close relative- penoplex, it is necessary to consider 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 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 plaster mixtures

To work with polystyrene materials, which include polystyrene foam and the like, it is necessary to use ready-made mixtures specifically designed for such work. Different companies producing dry building mixtures have several options for such mixtures in their assortment. 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, 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. All instructions must be followed to obtain the maximum 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 are working with external insulation, then the material for facade work is suitable for you. 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:

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.
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.
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.
After applying the mixture to corners or slopes, you need to apply plastering 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 unglued; they will be used at the time of joining.

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.
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.
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.
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 it is the autumn period, when it is damp and humid, then 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 wall insulation with foam plastic is applying a leveling layer. 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.

Process of applying a layer for leveling:

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.
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.
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 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:

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 thicker the layer is applied.
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.
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.

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 save your work and insulation of the house is considered to be applied facade plaster on foam plastic. Such protection will allow you to preserve the foam insulation of the house, even if the 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 reinforcing adhesive layer and apply primer to the dry surface deep penetration with acrylic base.

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- these are always costs, and sometimes considerable ones. Count and purchase exactly according to the estimate several types of different plaster mixtures and adhesive compositions, as experienced craftsmen do, is quite difficult. 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. Well-known 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 façade mesh has a special protective coating that improves the adhesion of fibers to 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:

From a common roll, individual mesh sheets are cut according to the height of the facade 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. Tape façade surface start from top to bottom, immediately apply half the height of the run;
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;
Final stage- 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 of the façade 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 home there are quite a lot problem areas Where facade plaster experiences additional loads is 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 of laying glue on the mesh is similar to the previous case, but there is a nuance - small pieces of canvas, especially for plaster 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 finishing with facade decor, then 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. Apply a leveling layer with a wide spatula facade finishing on 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.

Yellow facing brick
What better siding vinyl or acrylic
Polyurethane cornices
Wood-polymer deck board

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 is widely used in 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;
water saturated 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 at the 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.

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.
A plinth strip is attached to the bottom row of slabs, which is C-profile made of perforated metal. 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.
According to the manufacturer's instructions, prepare tile adhesive and mix it with an electric drill with a mixing attachment.
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.
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.
After gluing, the sheets of the first row are secured with disc-shaped dowels. Holes are drilled into the 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.
After attaching the insulation to the wall, apply a layer of glue with a spatula. Perforated corners are applied and secured to the corners of walls and window openings. They protect the edges of the insulation from mechanical stress.
Apply a layer of glue reinforced mesh(cell size 5 by 5 mm) and roll it 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.

Is it possible to paint wall mdf paper covered panels? Cover the base of a wooden house with asbestos cement under a round stone

High-quality insulation of a house is an integral stage of construction. Thermal insulation allows you to create a comfortable indoor climate and significantly reduces heating costs in winter. Often craftsmen choose foam plastic as thermal insulation - an inexpensive and proven material. But the building closed by it needs additional cladding. In this article we will talk about how and how to plaster polystyrene foam on facade walls.

Advantages and disadvantages of polystyrene foam when insulating a house

In polystyrene foam, the bulk of the material is gas. This determines its main advantages: light weight and good thermal insulation properties. Polystyrene foam is also a good sound insulator, since its structure dampens sound vibrations. In addition, the advantages of the material include:

environmental friendliness - complies with environmental standards and does not harm humans and the environment;
durability - resistant to mold, rot and corrosion;
light weight - easy to transport, no additional load on the foundation;
ease of processing and installation;
affordable price.

In addition to the advantages, there are also disadvantages:

Low strength. This is the main reason why the insulation layer is covered additional material, since under mechanical influence its structure is easily damaged and it loses its thermal insulation qualities.
Incompatibility with nitro-based paints and varnishes. These substances can corrode the foam mass.
Does not allow air to pass through. Poor vapor permeability does not allow its use in interior decoration residential premises. Without good ventilation, the house turns into a thermos.
Rodents and insects are partial to polystyrene foam that is not protected by plaster or a durable finish.
Fire hazard - burns and releases hazardous substances.

Characteristics, scope and price

Its price depends on the density of the material. The following brands of foam plastic are produced in Russia.

PSB-S 15. Density 8-13 kg/m3. Insulation of walls, floors, non-load-bearing roofs. Price from 1300 RUR/m3.
PSB-S 25. Density 15-22 kg/m3. More dense and durable than C 15. The areas of application are the same. Price from 2100 RUR/m3.
PSB-S 35. Density 25-30 kg/m3. Durable and cheap material. Can already be used for thermal insulation of a loaded roof. Price from 3600 RUR/m3.
PSBS 50— Density 35-37 kg/m3. Highly durable. It has high density and strength. It is used to insulate the foundations of industrial and residential buildings and loaded roofs. Prevents soil freezing and swelling. Price from 4700 RUR/m3.

All brands of polystyrene foam contain a fire retardant, which promotes self-extinguishing. But despite this, the material still belongs to the fire resistance class G4 - highly flammable.

Choosing plaster for the facade

The choice of external finishing must be approached seriously, because the service life of the insulation depends on it. Plaster allows you to solve problems:

Protection against mechanical damage. Fragile polystyrene foam easily crumbles and dents, so it must be protected from impacts.
Waterproofing. Expanded polystyrene, although poorly, still absorbs moisture (up to 2% by volume when fully immersed). At the same time, it takes a very long time to dry. Wet foam retains heat much worse. Its strength decreases.
Sun protection. Ultra-violet rays dry the foam. Over time, it begins to crumble.
Improving fire safety. The plaster layer will protect the insulation from fire.

For finishing external walls, insulated with foam plastic, you will need 2 or 3 types of mixtures, depending on the final finish:

1. Glue solution based on cement, sand and polymer additives. It is used when installing insulation sheets to street walls and to create a base layer with reinforcing mesh. Decorative finishing will already be applied on top of it. You can use, for example, Ceresit CT 83, Weber.Therm S100, Unis Warm Adhesive, Knauf Sevener (universal adhesive mixture).

You can prepare this mixture yourself using a mixer. The proportions of materials will be different depending on the brand of cement. For example, for the M400 brand, take 4 parts of sifted dry sand for 1 part. For plasticity, lime and surfactants are added. Mixing it yourself helps you save a lot when plastering.

Ready-made CPU mixtures are available in almost every hardware store. Here are several popular brands: Knauf Unterputz, Forman No. 61, Osnovit Startwell PC2, Volma Aquaslayer, etc. The price of ready-made mixtures is around 200-300 rubles per 25 kg, depending on the manufacturer.

Decorative plaster goes well with other types of finishing: clinker tiles, natural stone and a smooth painted wall.

Polystyrene foam, like any other insulation material, needs a protective coating. Well suited for these purposes façade plastering . The process is not as complicated as it first seems.

We hope that our article was useful to you. Leave your feedback and questions in the comments below.

Facade Finishing a house with facade plaster: choosing the best mixtures for exterior work and covering the walls using technology

Facade Technology of facade plaster on polystyrene foam: cover the reinforced insulation with an adhesive mixture and cement mortar

Decorative plasters indoors are also covered with or. On the street, as a rule, only colorful compositions are used. These should be paints for external use. They are more resistant to UV rays and temperature changes and form a durable film.

It is more practical to choose for finishing using foam plastic decorative effects, which can be easily restored in case of damage. The bark beetle is not included in this number.

Caring for decorative plaster finishing simple Most compositions are suitable for washing even with the use of detergents.

Plastering doorways and slopes

After replacing window or door frames better insulation openings formed between the frames and the facade will be made of polystyrene foam slopes with plastering. You can make slopes as soon as the polyurethane foam has dried.

The simplicity of the work is similar to installing drywall. Blanks are cut out of PPS sheets and glued to the wall along the perimeter of the frame (foam plastic also needs to be mounted under the window sill. When the glue dries, dowels with fungus are installed. Plastering the foam is done in the same way as described above (corners are placed on the mortar, strips of reinforcing mesh are attached, etc. .d.).

In order not to stain the frames, they are covered with masking tape before starting foam plastic work.

Consumption of façade plaster on polystyrene foam

If styrofoam plastering is done with a universal facade mixture, then the consumption per square meter will be 10 kg. Using two types - adhesive and leveling plaster, prepare 4 and 6 kg per square, respectively. The same consumption - 9-10 kg will be if a polymer composition is used. Of these, 3.5-4 kg will be needed for gluing the insulation, the rest will be needed for plastering on foam plastic. .

Insulating a house with polystyrene foam is becoming more popular every year. Having familiarized yourself with how to plaster polystyrene foam, what materials are better to purchase for the facade than facade insulation Rather than insulating a room, you can easily solve many problems that arise during renovation or construction. Plastered thermal insulation will last longer if it is promptly tinted and repaired if the integrity of the “shell” is damaged. Your home will be safer, and you will be warmer and more comfortable in it.