Foam plaster for façade. Is it necessary to prime the foam before plastering? Applying a reinforcing layer to the foam

The walls are insulated with polystyrene foam, and after this is done, a new task arises. It is necessary to give the walls a finished look using a fine finish. Foam plaster is one of the finishing options. The second option is hanging panels. But unlike plaster, this option is too expensive. In order for the plaster to hold up as it should, you need to choose the appropriate option and use the right technology.

Options

Mineral mixtures

The most commonly used mineral plaster is slaked lime and cement. The filler is sand and stone chips. You can use “bark beetle”, “fur coat”, “lamb”. All these types differ in that they contain different fractions of stone.

In mosaic plaster for facade work, a large fraction of crumbs is used. Characteristics of the “mosaic”:

Resistant to dirt and precipitation.
Impact resistance.
The mixture can be applied either by machine or by hand.
Wide range of colors.
Eco-friendly and durable.

What are the proportions of the cement composition for plastering walls can be found out from this

The mosaic mixture is applied with a metal trowel, a method called “wet on wet”. This means that the mixture is applied to the first layer without waiting for it to dry.

What qualities does acrylic plaster have?

The elasticity of the surface is high even after drying, which cannot be said about mineral plaster.
Resistant to various mechanical damages.
Atmospheric manifestations are tolerated very well.
25 years is the maximum service life, and the minimum is 15.
Good adhesion.
Aesthetic properties at the highest level.

You can find out about the consumption of Rotband plaster from this

It is worth considering that dyes are added to acrylic plasters. As a result, in the sun, under the influence of ultraviolet radiation, the color will fade and fade. Absorbs dirt and dust well. And another significant drawback is the price. For one package containing 25 kg, you will have to pay at least 1,500 rubles.

How to apply plaster on polystyrene foam correctly? To do this, you need to carry out a number of preparatory work. The first thing to do is prime the wall. To do this, you need to take a composition that is hydrophobic and biostable. If you decide to make a painted surface, then you need to take a painted mixture. Now you need to dilute the dry mixture with water and mix with a construction mixer. Now, using a trowel, the plaster is applied to the surface. Next, the coating is brought to the desired state.

What is the consumption of gypsum plaster per 1 m-2 can be found out from this

In the video - do-it-yourself polystyrene plaster:

Manufacturers and prices

The construction market offers a lot of options for choosing one or another type of plaster. Each manufacturer offers its own composition, price and packaging.

Knauf is a German company that has been operating on the market since 1932. The plaster from this manufacturer is of high quality and good resistance to various external influences. Even plasters from this manufacturer have different compositions. Knauf Unterputz is the most popular plaster among buyers, made on a cement base. The mixture is presented in dry form, with well-fractionated sand and additives added. The purpose of the additives is to improve the properties of the plaster. This plaster is applied to the surface either manually or using special tools. This type of mixture is ideal for giving the wall an ideal surface; the surface can then be painted. This plaster has good water-absorbing properties, high strength and ductility. Due to this, the surface does not crack when drying. The price starts from 250 rubles per package. Read more about it in our article.
Ceresit– also represented by a company from Germany. It is best to use dry mixtures and do the preparation yourself by studying the instructions. High elastic properties, hydrophobicity, strength, wear resistance. Among the presented assortment, you can choose the desired color scheme. Ceresit plaster can protect from rain, wind, snow, and sun. All mixtures are non-allergenic. This is especially important for people with allergies; no toxic substances are released. Ceresit st35 is represented by “bark beetle” plaster. The main base color of this plaster is white. It is possible to add color. After coating, the wall will appear to be covered with grooves. Mineral st137 Ceresite appears in the form of pebbles. Burnout and any precipitation are not scary for her. There are varieties according to the size of the added particles. Plaster Ceresit st60 – acrylic. It has a fine grain and is applied in a thin layer. The composition includes a dry mixture with filler. And the filler can have different color shades. The price of a Ceresit bark beetle package starts from 600 rubles. Acrylic will cost more - from 1,400 rubles per package. And individual fillers cost from 1,200 rubles.
Bolars– the company provides a lot of plastering options to choose from. The plaster mixture from this company consists of cement, lime, and a small amount of modifying additives. All Bolars dry mixes are produced in 25 kg packages. Each package contains instructions that must be followed. Mix the dry mixture with water and mix thoroughly. As a result, you will get a mass that looks like plasticine. The fluidity of the solution is low, but the adhesion is high. In this regard, the plaster can fill all the smallest cracks, making them airtight. Bolars does not shrink, and therefore does not crack. The plaster from this manufacturer has high waterproofing properties. Wide temperature ranges for use. Temperatures range from -50 to +60. The price of plaster starts from 350 rubles. Further, the cost will depend on the type of plaster.

How to make it yourself

You can prepare the mixture yourself without buying ready-made ones. This is quite easy to do. Typically, the binding components are the following substances: clay, lime, cement. Sand is used as a filler, and water is used as a liquid. Most often, one aggregate and one binder are added to the plaster mixture. But there are cases when two binder components are added. Depending on what proportions you take, the type of mixture will depend:

fatty
normal
skinny.

The fatty mixture contains a lot of astringent component. This mixture cracks after drying. In a normal solution, the ratio of binder and filler is optimal. A lean mixture contains very little aggregate, resulting in a very brittle solution.

The video shows the finishing of the facade with foam plastic and plaster:

What technical characteristics of Rotband plaster can you find out?

Cement-sand suspension is the most common. The ratio of cement and sand in this solution is 1 to 3. The components are mixed dry at first, then water is added little by little. All components are thoroughly mixed. After this, you can add PVA glue at the rate: about 70 g of glue per 10 liters of plaster.

Lime mortar is also widely used. By gradually adding sand, its fat content is controlled. And the strength changes by adding cement. 1 kg of cement is needed for 10 kg of mortar.

Cement-based mineral coatings often do not give the desired result. Namely, the color and shine turn out dull. When using dry mixtures, it is important to dilute correctly with water. If the layer is very thin, the solution will lie unevenly. And too thick plaster will simply fall off the wall, as a result of which the planned consumption will increase. Usually the mixture is thick, like sour cream. But under certain conditions this indicator may change.

Every year, thermal insulation of facades with foam plastic becomes the most popular method of insulating houses and buildings. But for all its advantages, polystyrene foam must be protected from external influences of climatic and biological factors. Facade plaster on polystyrene foam copes well with this task, provided that all work is carried out correctly.

If you have chosen polystyrene foam or penoplex as the façade insulation, there will be a need for high-quality plastering of the thermal insulation surface. Below we consider in detail how to properly plaster a building, protecting its thermal insulation from the harmful effects of natural and atmospheric phenomena.

Plastering on polystyrene foam consists of several stages, which are performed in a certain sequence:

Preparation of plaster mortar.
Preparation and pasting of the facade with plaster mesh.
Rubbing along the façade mesh.
Uniform treatment of the facade with plaster.
Rubbing an even layer of plaster.
Primer work.
Final decorative finishing of the facade with plaster.

Preparation of plaster mortar

To process expanded polystyrene, penoplex and other similar building materials for insulation, different types of plaster solutions are used.

Due to high-quality products that have proven themselves in the market, the most common manufacturers of such solutions are Stolit, Ceresit and Ecomix. The price of the above brands is affordable and has a good correlation with their quality.

It is important to know: when plastering a certain building, you need to use a solution or mixture from only one manufacturer.

Not all manufacturers of plaster mortars produce one mixture for treating thermal insulation of facades. There are manufacturers who make a separate solution for gluing plaster mesh to the wall and a separate mixture for treating facade insulation.

When purchasing a separate mixture for gluing the mesh, make sure that the plaster used for processing the thermal insulation of the facade belongs to the same manufacturer.

To glue a plaster mesh, it takes about 3.5 kg/m2 of solution, and the mixture consumption for uniform treatment of the entire facade is 5.5 kg/m2. When creating a solution, be sure to follow the required proportions, which are displayed by the manufacturer on the packaging itself.

Experts recommend mixing a solution that is slightly thinner than the manufacturer's recommended mixture. This will not affect the quality of the plaster itself and will create more comfortable conditions when applying it during finishing work. In particular, the layer intended for uniform treatment of the façade must be liquefied. The degree of liquefaction can be determined based on the level of drainage of the mixture from the spatula.

After preparing the required consistency of the plaster, proceed to the installation of the facade mesh, to which the polystyrene foam plaster will be attached.

Preparation and pasting of the facade with plaster mesh

When preparing plaster on polystyrene foam, it is imperative to adapt it to self-retention on the covering of the wall that you are going to process.

Without a facade mesh, it is impossible to reliably glue the plaster to the foam. For this reason, it is necessary to choose a suitable material for wall treatment. The best choice would be to purchase a mesh for external facade work, the density of which should be at least 150 g/m2. The most compacted mesh will facilitate uniform processing of the façade covering, but it is worth considering the difficulty that arises when gluing decorative elements and corners. These areas can be treated with a low-density net.

It is important to know: due to the fact that styrofoam plaster is most often made on a cement base, it is necessary to select an alkali-resistant mixture.

Gluing the façade mesh should begin from corners, arches, window and door slopes, as well as other difficult-to-work areas:

To glue the facade mesh in the corner areas, it is necessary to cut a belt from the mesh 30 cm wide and 1 m long (the length for a slope or arch is determined by measuring the required area yourself).
The belt must be bent directly in the center so that when unbent, the fold line is clearly visible.
The plaster solution is applied to the corner areas using a spatula; its density should be at least 2 mm.
Apply the mesh to the covering of the desired area of the facade and, pressing with a spatula, smooth it with gentle movements, starting from the corner to the bottom side.

After successfully gluing all difficult-to-process areas, you can begin gluing the facade mesh to the flat areas of the facade:

The length of the segments for uniform sections of the facade should be no more than 1 m, since you will not be able to glue a longer piece due to the quick-drying properties of the plaster mortar. If you are sure that you can do it on time, you can cut off larger pieces, but it is recommended not to take risks, otherwise there is a chance of damaging the building materials.

The plaster mixture is applied to the treated area of the wall in a layer of at least 3 mm, guided by the size of the prepared mesh section.

When attaching the mesh, press it with a spatula and smooth it, starting from the center in all other directions. Make sure that all sections of the mesh are well pressed into the applied plaster solution.

Having successfully glued one piece, you need to continue installing the mesh in the same row, moving to the right or left. Pasting of the façade mesh is done with an overlap. Edge joints, as well as slopes, arches and corners are glued in the same way.

It is important to know: pay special attention to the joints, corners and decorative elements of the facade, otherwise they will look sloppy even after the final exterior finishing.

Rubbing along the façade mesh

The glued mesh must be rubbed evenly without fail. This is done using a plastic grater with sandpaper.

Grinding is carried out exclusively on the dried solution. This usually takes a little time; for example, in summer it will dry in just 4-5 hours. In cooler seasons, it is recommended to wait about 20-22 hours before grouting.

Rubbing should be carried out using gentle movements in a circle, preferably counterclockwise. Be sure to change the sandpaper if undried solution gets into it.

Uniform treatment of the facade

After the above steps, facade plaster on foam plastic involves applying a leveling layer of the mixture. Uniform processing of the wall is carried out as follows:

A leveling plaster solution is applied to a large spatula, which must be used to evenly cover the facade wall. The thickness of the layer is selected based on the quality of the walls. In the best case, it is at least 2 mm.

Leveling is carried out by applying a layer of mortar in sections. In this case, it must be taken into account that the joints of the mesh should not fall on the joints of the leveled sections.

Rubbing an even layer of plaster

Rubbing a uniform layer is carried out using the same method as troweling over a façade mesh.

It is important to know: rubbing of a uniform layer must be done no earlier than 20-22 hours and no later than 4 days after processing the facade. If grouting is late, you will have to put in much more effort when processing the wall.

A uniform layer is rubbed down until an extremely even coating of the facade wall is obtained, since the decorative plaster will be applied precisely to this surface.

Primer work

In order for the final finish to adhere well to a uniform layer, it needs to be primed. Quartz primer (CT-16) is perfect for decorative plaster. In the case of regular facade painting, it is necessary to use a quartz-free primer to maintain an even finish (CT-17). When choosing a primer, you should pay attention to the Ceresit brand, as its price is about 450 rubles. and it correlates perfectly with the quality of the product.

The primer must be applied using a short-haired roller to avoid drips.
Having completed the priming work, you can begin the final finishing of the facade of the building.

Final decorative finishing of the facade with plaster

The final finishing of the facade should be carried out by applying the main layer of plaster to a spatula. Its thickness is determined based on the size of the mineral grains in the solution: the finer the grains, the thinner the layer. Make sure that the layer is applied evenly over the surface area of the façade wall.

The base layer must be leveled using a large-pored sponge or grater, while simultaneously forming the desired decorative elements of the facade. Before painting the facade or applying a protective solution, it is necessary to allow the plaster to dry.

This guide will help you treat polystyrene foam insulation with stucco yourself. Omission of at least one of the stages does not guarantee successful processing and durability of the building facade.

How to properly finish a facade using foam plastic using facade plaster

The simplest and most affordable option for insulating the facade of a building is the use of polystyrene foam. The material is not only very resistant to external damage, but also perfectly withstands exposure to a humid environment and ultraviolet radiation.

Unfortunately, when installing polystyrene foam, even with high-quality work, gaps form between the sheets of foam plastic, and this leads to a decrease in the effectiveness of the protective layer, and the appearance leaves much to be desired. To cope with the problem, you should not resort to complex design solutions and spend money on purchasing special finishing materials.

Regular facade plaster on the facade will help with this. The material is affordable and allows you to finish the walls of a building in an extremely short time. Let us consider all the issues related to the design of the building in more detail.

Facade plaster - advantages and disadvantages

Plastering walls finished with foam plastic, cannot be done with conventional plaster. This risks the fact that after drying, the mixture may simply fall off and plastering will have to be done again.

In this regard, it is extremely important to choose the right plaster that will fit well on the foam and can last for a long period of time. Let's consider which plasters are suitable for this purpose and will turn out to be the most suitable.

Before making a choice of plaster, let's study the foam itself. The following two important indicators can be distinguished:

this material has a smooth and even surface, so there may be problems with the adhesion of the mixture;
not every composition has a sufficient level of viscosity and can cling to a smooth surface. That is why it is important to choose facade plaster designed to work with polystyrene foam.

Experienced craftsmen recommend using the well-known and popular brands of finishing compounds Ekomix and Ceresit, however, it is worth noting that absolutely any plaster that has high adhesive properties to polystyrene materials can be used. The most important thing is to use a mixture from one manufacturer on the entire working surface to be plastered and not mix compositions of different brands.

The next thing you need to pay attention to is that some manufacturers recommend using foam gluing compounds followed by applying a protective layer. Others make universal mixtures suitable for all types of finishing work. The second option is suitable for those who want to save money, however, you should not count on the high quality of the finished finish.

This issue is especially relevant if we are talking about painting the facade, and not about additional finishing with decorative putty.

The following plasters are best suited for finishing facades:

If we talk about cost, then the most expensive compositions are polymer ones, however, they are the most durable and do not crack during application, as well as after drying. Each type of plaster has virtually no disadvantages, and buyers should choose the composition based on cost, features of the necessary work and ease of use. The easier it is to apply the composition, the faster the work will be completed.

Types of plaster mixture that can be used for application to foam plastic

Let's take a closer look at what types of plasters there are that are suitable for application to foam plastic.

Since we are talking about exterior decoration, then the plaster must withstand low and high temperatures well, as well as various atmospheric phenomena.

In this regard, gypsum compositions should be immediately excluded from the list of suitable mixtures.

So, we have already noted that the best option would be cement or polymer compositions, but not those prepared by mixing cement, sand and water at home, but those sold in hardware stores.

The thing is that additional components are added to special compositions, which provide the plaster with strength and durability. Let's consider which compositions are most preferable for application to polystyrene foam.

The following types of compositions exist:

Mineral. Sand, water and cement are used to create them. They are not durable, but have a low cost.
Acrylic. The mixtures are based on acrylic resins. The material perfectly allows air to pass through and allows the material inside to “breathe”. It has high vapor permeability.
Silicate. This plaster is sold in buckets, and it has an alkaline reaction. You need to work with it very carefully.
Silicone. They have increased elasticity and, when applied, form a uniform, beautiful layer.

In addition to the varieties, there are a few more important points. It is better to use thin-layer materials that are easy to apply and spread. Cement-sand compositions are characterized by low plasticity and cracks may form during application. All of these compositions are characterized by increased resistance to mold, fungi and algae.

Consumption of façade plaster on polystyrene foam

For plastering the facade of a building finished with foam plastic, two types of mixtures are used. The first is necessary for gluing the reinforcing mesh, and the second is used to level the surface. In addition, there are universal mixtures that are suitable for both types of work.

If you decide to buy two types of materials at once, then it is extremely important to correctly determine the amount of the required mixture. In this case:

glue consumption will be 4 kg per square meter, and plaster should be calculated based on 6 kg per square meter;
if we are talking about a universal mixture, then the consumption will be 10 kg per square meter;
to calculate polymer plaster, it is worth using an indicator such as 9-10 kg per square meter, provided that 3.5-4 kg will be spent on gluing the reinforcing mesh, and the rest will be required to create a leveling layer.

Preparing the surface for application

Before you begin plastering walls finished with foam plastic, it is very important to properly prepare the work surface. For this purpose, you will need:

seal the joints between the sheets using polyurethane foam and wait for it to dry;
if excess is formed, it must be cut off with a sharp knife;
most often, foam plastic is attached using “umbrellas”, so it is important to make sure that the caps are sufficiently recessed and do not protrude, since this will create additional difficulties when applying plaster;
After this, you will need to sweep the surface of the wall from dust and prime it. This will increase the adhesive properties of the wall and even simplify the work;
the next steps will be to reinforce and level the walls. If dry plaster is purchased for this purpose, then the mixture should be prepared before reinforcement begins, otherwise it will quickly lose its qualities.

If the foam is not securely fixed, it is necessary to correct this point, since after applying the plaster, unsightly cracks may form on it.

Reinforcement and priming

Reinforcement or application of a special mesh to the walls can be done in two ways:

In the first case, the mesh is applied to the prepared area and coated with plaster solution on top. The composition penetrates into the cells and the material quickly sticks. It is not easy to do such work alone, since you will need to hold the mesh with one hand and apply the mixture with the other, so it is better to first fix the mesh and then apply the solution.
The second method is to first apply plaster to a section of the wall, and then attach a mesh to it. Gradually pressing the cells into the composition with a spatula, the master glues the mesh to the surface.

Regardless of which reinforcement method is chosen, first you need to glue the corners of the building, doorways and slopes, and only then start applying the material to the total area.

To reinforce window and door openings, the mesh is cut into strips of 30-40 cm and, after bending, glued to the destination. After the plaster has dried, which may take from several hours to a day, you should rub it with sandpaper or a special grater to eliminate various irregularities.

After this, the surface of the walls is primed with a special composition that enhances the protective functions and qualities of the plaster itself. It is better to choose a liquid, homogeneous primer, which will give the coating roughness and provide better adhesion of the material.

Technology of façade finishing with polystyrene foam plaster

The last finishing stage is the application of a leveling layer.

Here the performer should be as responsible and attentive as possible, since the leveling layer should hide all defects of the reinforcing coating and prepare the basis for the final finishing of the walls - painting or covering with decorative putty.

In fact, this work is not particularly different from plastering walls made of concrete or brick.

It is worth using a standard spatula and applying the plaster in a thin layer.

The finishing must be especially careful and careful when it comes to subsequent painting, since all the unevenness in the future will only be emphasized by the paint and the walls will not take on a very aesthetic appearance.

To ensure that the surface is perfectly smooth, after the coating has dried, it is recommended to sand it using sandpaper or a special mesh. It is important to grout in the first 3-4 days, otherwise in the future the composition will harden greatly and it will be extremely difficult to sand it.

The exception in this case is textured finishing plaster, however, here everything depends on the grain size.

Useful video

Master class on insulating a wall with foam plastic and applying plaster:

Conclusion

In the prepared article, we tried to show how to correctly select and apply facade plaster to the walls of a building insulated with foam plastic. If you decide to cope with this task yourself, then carefully read the material presented and try to evaluate your capabilities. Only a properly carried out finishing process will create a coating that will protect the building from the negative effects of the environment and will extend the life of the building.

Procedure for plastering polystyrene foam

Expanded polystyrene, both regular and extruded, has become widespread as an insulating material. Its use is due to its affordable price and excellent thermal insulation properties.

Proper use of this material (fixing it to the walls outside the house) allows you to retain heat and prevent the formation of mold and mildew indoors.

To protect the insulation itself from the destructive effects of the external environment, polystyrene foam plaster is used. In this way, you can extend its service life several times.

Why is it necessary to plaster polystyrene foam?

Plaster is an important element of protective treatment. The technology for carrying out the work in this case differs in a number of nuances from conventional plaster. Polystyrene foam is characterized by a porous structure. This material is produced by filling styrene granules with gas under high pressure and heating with water vapor. Exposure to high pressure and temperature leads to swelling and sticking of granules together.

Afterwards, the mass of the resulting substance is pressed, giving it the shape of slabs. The thermal insulation properties of the resulting material are high, but it impairs natural ventilation in the house. Low cost relative to other insulation materials and low weight allow you to put up with its low strength.

As a result of atmospheric influences (ultraviolet radiation, humidity, temperature fluctuations), the bonds between individual granules weaken over time. The slab begins to crumble and may fall apart into pieces.

Due to these phenomena, it is necessary to apply a plaster coating to polystyrene foam. It plays a role protecting against negative influences.

Along with conventional polystyrene foam, the use of fire-resistant and extruded types of polystyrene foam is common in practice. The latter is the most advanced version of the material in the form of a single substance (rather than individual granules) with a strong connection of molecules. The absence of micropores prevents steam and water from penetrating into the structure. The negative effects of the atmosphere can be traced only on the surface, but also in places of cuts, so the use of extruded polystyrene foam is more preferable in the long term.

Tools and materials used

To plaster polystyrene foam surfaces, you need to use a certain set of tools. The necessary tools and their purpose are described in the table.

No. Name of the tool Purpose 1 construction mixer is intended for stirring the solution to the required consistency; 2 set of spatulas is used to apply the mixed composition to the work surface; 3 construction float removing minor irregularities, sanding; 4 set of containers for water, for solution; 5 construction knife, hacksaw for cutting slabs and fiberglass mesh, applying notches;

After preparing the tools, the question arises about choosing plaster. The materials offered differ in price and composition.

To carry out finishing work, you will need special plaster (facade) for polystyrene foam.

Its most common types with brief characteristics are presented in the following table.

No. Type of mixture (by composition) Characteristics 1 mineral compositions are sand-cement mixtures with the addition of various fillers;
very low cost;
the quality is much lower than that of analogues;
now 2 acrylic plaster materials main components - acrylic resins, chemical additives;
excellent quality (they are created specifically for finishing insulated facades);
There is no special need to prepare extruded foam plastic for plastering;
fits well on the surface being treated;
allow you to create decorative elements and textured images on the facade

Choose fire-resistant mixtures

This is by no means a complete list. Modern manufacturers offer a large selection. Some samples may differ in only one or two of their components.

Mixtures from the companies Knauf, Ceresit, Polyrem, Kreisel (for example, brands of universal adhesives CeresitCT-85№, Coral SP-141, PoliminP-19) have gained particular popularity.

When choosing, you should pay attention to the fire-resistant properties of the compositions, because most polystyrene foams have an average degree of flammability; it is recommended to use plastering materials that are more fire-resistant.

Plaster is produced for sale (mostly) in bags of 15 to 25 kg weight.

It is not recommended to carry out plastering work with a solution of cement and sand. Such surfaces will not last long.

You will also need water and fiberglass mesh (prevents the formation of cracks, holds the plaster).

according to the consumption data indicated on the packaging per 1 sq. m of treated surface;
purchase (approximately) mixtures for one wall;
After plastering, calculate the practical consumption and purchase more for the required area.

Features of working with extruded polystyrene foam

Plastering extruded polystyrene foam has a number of differences due to its physical characteristics.

The most characteristic properties that show the nuances of working with this material are:

moisture is not absorbed into the insulation boards, so all the water from the facade remains inside the finishing layer;
the coefficient of expansion (temperature) of polystyrene foam does not correspond to this indicator for plaster mixtures, therefore, due to temperature changes, the coating applied to the slabs may crack and fall off;
The surface of the insulation is smooth, dense, irregularities and micropores are virtually absent, which makes it difficult for the solution to adhere to it.

If the material is too smooth, it is roughened

Before starting work, you need to apply a small amount of plaster mortar to the slab and wait a day. If the coating was difficult to apply, cracked or fell off after drying, then additional treatment of the contact layer should be carried out.

It consists of increasing the roughness of the interacting part of the slab using a needle roller or small plastic brushes. Afterwards, a special primer and reinforcing mesh should be applied. The latter is fastened either with a special adhesive composition or with the residue left over from working with insulation.

Due to the low adhesion ability and weak adhesion, the thickness of the applied layers of the solution should not exceed 3 mm.

Extruded polystyrene foam requires a plastering technology that differs from the standard process.

Process technology

Expanded polystyrene plaster is performed in two layers: the 1st - creates a coating of the reinforcing mesh, the 2nd - levels the surface. The work takes place in several successive stages:

to increase the degree of adhesion between the materials, notches are made on the surface of the insulation boards (using a hacksaw or a needle roller in increments of about 5 cm);
From the beginning, the door and window openings of the building and its corners are reinforced with fiberglass mesh;
complete covering of a reinforced wall with mortar;
rubbing the first layer;
applying a second plaster layer;
final (final) grouting;
primer for finishing. For more information about plastering, watch this video:

The solution layer should be 2 - 3 mm

At the second stage, for corners and openings, the mesh is cut into strips of the required length (on average up to 1.5 m) and about 30 cm wide. They are bent in half and tried on the corner (opening).

For the mesh, following the instructions on the packaging, make one bucket of solution (to have time to process it before it starts to dry). It is applied with a spatula on both sides of the corner (10 cm in each direction from the corner). The remaining 5 cm unprocessed is necessary for overlapping the next strips.

The solution is applied in a layer of 2-3 mm. The prepared mesh is pressed into it with a spatula from top to bottom. A ready-made mesh profile is also used for corners.

Then the entire wall is reinforced: the mesh is pressed into the solution, covered with a layer of plaster. Work quickly to allow the solution to set. Mesh joints should not coincide with the joints of insulation sheets.

When the plastered surface dries (this will take about 2 hours), then it is rubbed using circular movements with a special grater, which must be periodically moistened with water. Minor roughness should be left for better adhesion to the second layer. For more information about finishing polystyrene foam, watch this video:

The finishing layer is applied the next day, followed by more thorough grouting. The surface is primed with a short-pile roller (does not leave smudges) for decorative finishing. Work is carried out in warm (above 5 degrees) calm weather.

You can do the work yourself. The most important condition for obtaining a high-quality result is the use of suitable compositions and adherence to work technology.

Plastering extruded polystyrene foam: how and how to plaster polystyrene foam

Today everyone is insulating their homes. This is a necessary measure to save energy sources in general and money in a particular family. Therefore, almost everyone studied technologies and materials for creating a thermal insulation layer.

Most sources mention that polystyrene foam must be plastered. Let's figure out why and how to do this right now.

Why is finishing necessary?

The material is created by foaming polystyrene and adding binders that hold the granules together. Unfortunately, these bonds are not very strong and are destroyed when exposed to factors such as:

solar radiation;
some service life;
Atmosphere pressure.

Even new material is very fragile. If you hit an unprotected slab, a dent will form, and the corners are already easily broken.

This is why polystyrene foam requires protection. Plastering is often used as a protective layer, since it is an affordable way to decorate the facade.

Required Tools

In order to quickly and efficiently apply the plaster solution to polystyrene foam, you will also have to acquire a set of tools. To do this you will need:

Containers for mixing the solution.
Perforator (used both for preparing the mixture and for fixing polystyrene foam).
Brush or spray bottle for applying primer.
A sharp knife for cutting reinforcing mesh and insulation boards.
Wide spatula for applying the solution to the surface.
Narrow spatula.
A grater for leveling the layer.

It’s unlikely that everyone will have such a set, so when you go shopping for materials, don’t forget to immediately purchase the tools.

Types of plastering materials

This material requires the selection of a special plaster composition. Not all plasters are suitable for polystyrene foam. Some options contain components that destroy the foam immediately. Therefore, in the store, be sure to check with the consultant whether the composition will be suitable for work on this insulation or not.

Mineral

The most affordable option. It consists of cement, sand and mineral fillers that improve the properties of the layer after hardening. It is sold in the form of dry mixtures, which must be diluted with water in a certain ratio before starting work. The manufacturer must indicate the proportions on the packaging.

It is quite possible to make such a solution yourself. In this case, sand and cement are purchased separately and during the preparation process the required volumes of each component are measured separately. So, it’s more difficult to work, especially if you need to prepare half a portion to finish a small area.

Mineral plaster is of lower quality. Difficulties arise during application, since it has poor adhesion with polystyrene foam. To increase adhesion, the insulation is treated with a special primer and small cuts are made across the entire surface.

Acrylic

A more expensive option for plaster mixtures, but at the same time higher quality. This type of plaster on polystyrene foam does not require special preparatory work, since it has high adhesion rates to any materials.

The main components are acrylic resins along with chemical additives. Such mixtures were created exclusively for finishing facades after insulation. Therefore, it can withstand various loads well. The treated surface remains attractive for a long time and is easy to clean.

Using acrylic plaster, you can create textures or immediately use decorative compositions. For example, the “bark beetle” has inclusions that, after rubbing, form grooves. Using different grouting techniques you can create an original design.

Features of this finish

It is difficult to apply plaster on this insulation for the following reasons:

smooth surface - the solution can slide; if you manage to apply it, it can crack or fall off after drying;
lack of hygroscopicity - moisture from the plaster solution is not absorbed into the polystyrene foam, but remains in the finish, which significantly extends the drying time;
the difference in the thermal expansion values of the insulation and finishing material, which causes cracking of the latter.

To avoid such problems, you should carry out preparatory work and do everything as clearly and correctly as possible:

Walk along the surface of the polystyrene foam with a needle roller or make cuts with a sharp knife. This creates depressions where the solution can “catch.”
Be sure to coat it with a primer that increases adhesion.
There is no way to do without a mesh for reinforcement.
The maximum thickness of the applied layer cannot exceed 5 mm.

How to plaster extruded polystyrene foam - technology

If insulation boards are installed on the walls of a building, it is necessary to cover them with finishing as quickly as possible. Professionals recommend doing this immediately after the glue used to fix the material has dried.

Carrying out calculations

It is better to buy material for plastering with a reserve. I wouldn’t want to run for an extra bag in the midst of work. But how do you know how much materials you need? To do this, carry out a simple calculation:

calculate the area of the walls being processed without taking into account window and door openings;
on the packaging of the decree the approximate consumption of the mixture per square meter. For different compositions it fluctuates in the range of 4–6 kg;
multiply the indicated value by the area to be treated and obtain the required amount of mixture;
We add another 10% to the resulting value - this will be the final amount.

Preparation of plaster mixture

Usually the manufacturer provides instructions for preparing the solution, so be sure to study the packaging and recommendations. If you are plastering polystyrene foam for the first time, do a small batch first to get used to the solution and the execution process.

Pour the dry mixture into the container.
Add water in small portions.
You can mix by hand, use a hammer drill with an attachment or a construction mixer.
When the consistency is completely satisfactory, leave the solution for 5 minutes to ripen and stir again.

In some cases, it is necessary to make the solution a little thinner than indicated in the instructions.

Pasting with reinforcing mesh

First of all, corners and slopes are processed. To do this, cut the reinforcing mesh into strips so that there are 10–15 cm of material on both sides of the corner.

a thin layer of mortar is applied to both sides of the corner;
apply a mesh and smooth it from the corner so that the material is completely immersed in the solution;
if the length of the piece is not enough, make an overlap of 10 cm; you cannot glue it to the joint.

The wall is covered with mortar.
The width of the strip is slightly larger than the size of the reinforcing mesh.
Apply the material and smooth it using a wide spatula or smoother.
The next layer of mesh is located on the previous one, by 10–15 cm.

Grouting plaster mesh

The first layer must dry completely. After this, use a grater and sandpaper to process the surface using light circular movements. This will remove small unevenness and help you use less leveling solution.

Leveling the surface

We prepare a new solution and begin leveling the plastered polystyrene foam. Now work with a wide spatula:

a small amount of solution is collected onto a wide spatula;
applied to the wall using arc movements from top to bottom;
layer thickness no more than 3 mm.

Make sure that the surface is as smooth as possible.

Grouting the second layer

Grouting is started only after the layer is completely dry. They work with the same grater and sandpaper. Just be sure to select fine grain to remove small flaws. Otherwise, you can simply ruin the whole job.

Primer

This stage should not be neglected. If you do not coat the base with a primer, the decorative layer will either be poorly applied or quickly lose its attractiveness. The composition of the primer depends on the finishing method:

Further decorative plastering - a composition containing quartz sand is used, it helps to increase adhesion.
Painting - a composition without sand, makes the base even smoother.

Finishing

Having chosen one or another finishing method, they act strictly according to the plan provided by the manufacturer. Both painting and decorative plaster have their own nuances and methods of applying the material. Therefore, you will have to study a few more articles to figure out how to do everything correctly.

Prices for services and materials

If the owner plans to do all the work himself, then his costs will only include materials. Need to buy:

Expanded polystyrene – thickness 50 mm from 110 RUR/pack.
Adhesive for foam plastic – from 350 rubles/can or from 420 rubles/25 kg of dry mixture.
Fiberglass reinforcing mesh - from 780 rub./roll.
Plaster for the facade - from 250 rub./25 kg.

And materials for decoration, either paint or decorative plaster. There is also the option of hiring professional workers who will do everything quickly. The cost of their work depends on:

number of storeys of the building. Finishing a private house will cost a little less than performing work at height;
will the customer purchase the materials or will they take their own;
total finishing area.

Polystyrene foam plaster technology

Expanded polystyrene is one of the most common materials for insulating external walls. It is correct to insulate the outside with polystyrene foam, then fungus and mold will not form in the house. At the same time, the insulation must be protected from external influences, such as sunlight, ultraviolet radiation, temperature changes, and precipitation. Protection methods may be as follows:

covering with siding panels;
painting with rubber paint or varnish;
plaster on polystyrene foam.

In this article we will talk about the last protection option - plaster. This type of protection is highly durable, durable, and has many decorative solutions.

Expanded polystyrene plaster

Necessary materials

Ready dry mix;
Fiberglass mesh;
Water.

For expanded polystyrene, special façade plaster for expanded polystyrene is required. Most manufacturers have such mixtures. As a rule, dry mixtures are sold in bags weighing 15-25 kg. It is not worth plastering polystyrene foam with ordinary cement-sand mortar - even if you can plaster a wall, such plaster is not very durable.

The composition of ready-made dry mixtures includes special additives; they help to better adhere the mixture to the surface of polystyrene foam.

Typically, the consumption of the mixture for plaster in 2 layers is approximately 4-6 kg per 1 square meter. We recommend purchasing the minimum amount of material per wall. When you plaster the first wall and count how many kilograms of mixture were used, then you will be able to determine the exact consumption of bags of plaster.

Fiberglass mesh is a mandatory material for polystyrene foam plaster. It holds the plaster and prevents cracks from forming.

Preparing the tools

To work you need:

large spatula;
small spatula;
construction grater or grater;
construction knife-cutter;
hacksaw;
containers for solution and water, respectively;
construction mixer.

Plaster application technology

Facade plaster on polystyrene foam is applied in two layers:

first layer of plaster with mesh reinforcement;
the second layer is leveling and fixing.

In this case, the work will take place in several stages.

Stages of facade insulation of a building

First stage: making notches on polystyrene foam

It is necessary to make notches for better adhesion of the solution to the surface of polystyrene foam. This is especially important to do on extruded polystyrene foam, because its surface is too smooth.

We make notches with a hacksaw or a needle roller along the diagonals of the sheets. The step should be about 5 cm.

Second stage: reinforcement of corners and openings with fiberglass mesh

Before plastering the entire wall, it is important to reinforce the corners of the building, door and window openings.

We cut the mesh into strips 30 cm wide, the length depends on the length of the opening; for the corners of the building, cut strips of 1-1.5 m. We bend the mesh in half along the width and press the fold with such force that after this the mesh retains its shape along the fold.

We dilute the solution from the prepared mixture according to the instructions. The solution should be diluted in no more than one bucket, so that you always work with fresh solution.

Apply the solution to both sides of the corner with a spatula 10 cm wide, 5 cm long less than the length of the mesh. We leave these 5 cm without mortar, because we will overlap the second strip of mesh over the previous one, and we will rub them together into one layer of mortar. The thickness of the solution should be 2-3 mm.

We apply a strip of mesh onto the solution so that the fold of the mesh lies exactly on the edge (corner) of the wall. On the sides on each side, 5 cm are left without mortar, the principle is the same as along the length - in the future we will attach the next strip of mesh overlapping the corner one.

Now we press the mesh with a spatula into the solution, starting from the top, down and to the side. The plaster should completely cover the mesh.

At the corners you can use a ready-made profile with a mesh

Third stage: plaster the wall completely

When all the corners and openings have been reinforced, we reinforce the entire wall with mesh.

We dilute the mixture according to the instructions, use a wide spatula to apply the solution onto the polystyrene foam in a strip 90 centimeters wide across the entire height of the floor. A solution of 90 cm is needed in order to leave 10 cm of mesh for reinforcement with a second strip overlapping the first.

The first strip overlaps the reinforcing strip of the corner of the building. The thickness of the solution should also be 2-3 cm.

Starting from the top, press the pre-prepared mesh strip into the solution with a spatula, completely hiding it under the plaster. You need to work quickly enough so that the solution does not have time to set.

This way we reinforce the entire wall.

It is advisable that the joints of the mesh do not coincide with the joints of the expanded polystyrene sheets.

Stage four: rubbing the first layer of plaster

After the first layer has dried, about 2 hours, rub it with a grater in a circular motion. We periodically lower the tool into a container of water, i.e. we wet it. The wall should not be troweled too smoothly; rough edges should be left for adhesion of the second layer of plaster.

Fifth stage: second layer of plaster

The next day you can begin the final stage of plastering.

We prepare a fresh solution, apply it to the wall with a large spatula 2-3 mm thick. You can work with a grater or a grater, whichever is more convenient for you. We leave the plaster to dry for several hours until it hardens.

Stage six: finishing grouting

We grout using a float soaked in water in the same way as in the fourth stage. Here the plaster needs to be rubbed down more carefully, preparing the surface for decorative finishing.

We insulate the apartment

That's the whole technology of polystyrene foam plaster. Working with polystyrene foam is not so difficult, the main thing is to take into account 3 main points:

mandatory reinforcement with fiberglass mesh is required;
it is necessary to make notches on the extruded polystyrene foam;
the solution must be made from specially made plaster for polystyrene foam.

Video on the topic

– this is the use of polystyrene foam. The material is not only very resistant to external damage, but also perfectly withstands exposure to a humid environment and ultraviolet radiation.

Before making a choice of plaster, let's study the foam itself. The following two important indicators can be distinguished:

this material has a smooth and even surface, so there may be problems with the adhesion of the mixture;
not every composition has a sufficient level of viscosity and can cling to a smooth surface. That is why it is important to choose facade plaster designed to work with polystyrene foam.

Experienced craftsmen recommend using well-known and popular brands of Ekomix finishing compounds and, however, it is worth noting that absolutely any plaster that has high adhesive properties to polystyrene materials can be used. The most important thing is to use a mixture from one manufacturer on the entire working surface to be plastered and not mix compositions of different brands.

This question is especially relevant if we are talking about, and not about additional finishing.

The following plasters are best suited for finishing facades:

cement-polymer;
polymer.

Types of plaster mixture that can be used for application to foam plastic

Let's take a closer look at what types of plasters there are that are suitable for application to foam plastic.

Since we are talking about exterior decoration, then the plaster must withstand low and high temperatures well, as well as various atmospheric phenomena.

In this regard, gypsum compositions should be immediately excluded from the list of suitable mixtures.

So, we have already noted that the best option would be cement or polymer compositions, but not those prepared by mixing cement, sand and water at home, but those sold in hardware stores.

The following types of compositions exist:

. Sand, water and cement are used to create them. They are not durable, but have a low cost.
. The mixtures are based on acrylic resins. The material perfectly allows air to pass through and allows the material inside to “breathe”. It has high vapor permeability.
. This plaster is sold in buckets, and it has an alkaline reaction. You need to work with it very carefully.
. They have increased elasticity and, when applied, form a uniform, beautiful layer.

Consumption of façade plaster on polystyrene foam

If you decide to buy two types of materials at once, then it is extremely important to correctly determine the amount of the required mixture. In this case:

glue consumption will be 4 kg per square meter, and plaster should be calculated based on 6 kg per square meter;
if we are talking about a universal mixture, then the consumption will be 10 kg per square meter;
to calculate polymer plaster, it is worth using an indicator such as 9-10 kg per square meter, provided that 3.5-4 kg will be spent on gluing the reinforcing mesh, and the rest will be required to create a leveling layer.

Preparing the surface for application

Before you begin plastering walls finished with foam plastic, it is very important to properly prepare the work surface. For this purpose, you will need:

seal the joints between the sheets using polyurethane foam and wait for it to dry;
if excess is formed, it must be cut off with a sharp knife;
most often, foam plastic is attached using “umbrellas”, so it is important to make sure that the caps are sufficiently recessed and do not protrude, since this will create additional difficulties when applying plaster;
After this, you will need to sweep the surface of the wall from dust and prime it. This will increase the adhesive properties of the wall and even simplify the work;
the next steps will be to reinforce and level the walls. If dry plaster is purchased for this purpose, then the mixture should be prepared before reinforcement begins, otherwise it will quickly lose its qualities.

NOTE!

It is very important to remember that plastering can only be carried out on insulation that is firmly fixed.

If the foam is not securely fixed, it is necessary to correct this point, since after applying the plaster, unsightly cracks may form on it.

Reinforcement and priming

It is worth using a standard spatula and applying the plaster in a thin layer.

An important point that must be taken into account when finishing is that the joints of the sections should be mixed relative to the joints of the mesh. In other words, sutures should not overlap each other.

The exception in this case is textured finishing plaster, however, here everything depends on the grain size.

Useful video

Master class on insulating a wall with foam plastic and applying plaster:

Conclusion

In contact with

External insulation of house walls with polystyrene foam is gaining increasing popularity. However, this material requires additional protection from external influences, so styrofoam plastering is practically no alternative method.

This material is dedicated to the features and nuances of the technology for plastering foam plastic insulation of a house.

So, you have decided to insulate your house with polystyrene foam or its close relative - penoplex. How to protect the insulation layer from mechanical influences, moisture, temperature and ultraviolet radiation? There is only one way out - plastering.

Plastering on penoplex or polystyrene foam includes the following steps.

Preparation of mixtures.
Preparing and gluing the mesh to the walls.
Grout.
Alignment of walls.
Grouting the leveling layer.
Primer.
Do-it-yourself finishing with decorative plaster.

Preparing the mixtures

To apply plaster to polystyrene foam and related materials, various mixtures are used to work with polystyrene materials. The leading manufacturers are Ceresit, Ecomix, Stolit.

Some manufacturers' product line for working with polystyrene boards contains one universal mass, while others have two, one for gluing foam to the base, the second for creating a protective layer.

For gluing mesh onto the walls and performing further work, it is the universal mass that is used.

Consumption is about 4 kg/m2 for gluing mesh and up to 6 kg/m2 for.

As practice shows, for gluing the mesh it is most convenient to use a mixture with a consistency slightly thinner than the manufacturer recommends.

For the leveling layer, the mass should be quite liquid and practically flow off the spatula.

Now that we have figured it out, we can start gluing the mesh on which the foam plaster will be fixed.

Sequence of work

Gluing the mesh

Before plastering the foam, care must be taken to ensure that the leveling compound can adhere to the surface being treated.

In order for the mass to hold securely on the foam, the use of a mesh is mandatory. The best option is “mesh for external facade work”, with a density of 140-160 g/m2. As a rule, the denser it is, the smoother the layer is, but at the same time, it is more difficult to paste over the corners with a dense mesh.

Note! Since cement-based masses are often used for plastering polystyrene foam, the mesh must be alkali-resistant.

Pasting walls with mesh begins with gluing the corners (including the slopes of window and door openings):

To glue it to a corner, cut a strip 30 cm wide and a length equal to the size of the slope.
We bend the strip exactly in the middle so that when the force is removed there is still an “edge” on it.
Using a spatula, apply the universal compound and corners. Thickness – 2-3 mm.
We apply the mesh to the surface to be pasted, press it with a spatula and smooth it out with movements from the corner to the side and down.

After the corners are glued (there should be parts that are not glued - they will be used for gluing the joints), we proceed to gluing the planes:

We cut the mesh from the roll into 1 meter pieces.
Using a 350 mm spatula, apply the universal compound to the wall in a strip 1 m long, 90 cm wide (5 cm from each edge will be used to glue the mesh joints) and a layer of about 3 mm.
We apply the mesh and, using the same spatula, smooth it out from the center and from top to bottom. The mesh should be almost completely pressed into the adhesive mixture. When smoothing, you can add a little mixture to the spatula to completely cover the structure.
After one vertical strip is completely glued, we move to the side and glue the next one, laying it overlapping so that the joints of the strips are securely glued.

Gluing plaster mesh onto polystyrene foam

We overlap the joints in the places where the corners are glued.

Note! If you do not leave any areas of the mesh that are not glued, the resulting joint looks quite rough and can stand out even through the fine finish.

Grouting mesh

The glued (more precisely, glued into the universal mixture) mesh must be rubbed down. Grouting is done using a plastic float with an emery cloth.

We grout using the dried mixture. In the warm season, the mixture dries within a few hours; in cooler, cloudy weather, it is better to wait at least a day.

Rub the mixture with a little force, using circular movements counterclockwise. If undried material gets into the sanding cloth, it will have to be replaced.

Applying leveling compound

Next, plastering on foam plastic (or similar insulating materials) involves applying a leveling layer. To apply it, the same “universal mixture for arranging a protective layer” is used.

Application technology:

Using a small spatula, apply the leveling mixture onto a wide spatula (350 mm or more).
Using a spatula, apply the mixture evenly onto the wall. The application thickness depends on the quality of the mesh grout and averages about 3 mm.
We apply it in sections, trying to place the joints of the sections away from the joints of the mesh.

Grouting the leveling layer

Grouting is done using the same technology as grouting over a mesh.

Grouting the leveling layer

Note! It should be grouted no earlier than 24 hours later, but no later than 4 days after application. Otherwise, you will have to make considerable efforts to carry out the procedure.

We rub until we get the most even surface possible. It is on this that we will apply the finishing finish, for example, decorative or.

Applying primer

In order for the finish to adhere reliably, it is necessary to prime the base. For decorative facade plaster, a primer with quartz grains is suitable (we recommend Ceresit CT 16). If we do not plan to plaster, but limit ourselves to painting the facade, we can use a primer without quartz grains, which leaves a smooth surface (we recommend Ceresit CT 17, price from 556 rubles).

Apply the primer using a short-haired roller, being careful not to leave drips.

After the surface is primed, we can begin finishing our insulated building!

Applying decorative plaster

We apply it to a leveled and primed base using the following technology.

Using a spatula, apply a base coat of finish. The thickness of the application must be uniform over the entire area of the wall being plastered and depends on the size of the mineral grains included in the plaster mixture. The larger the grain, the thicker the plaster.
After this, on a small area using a sponge with large pores, a spatula or a grater, we begin to form a decorative texture.
When the entire area is covered and the texture is applied, leave the surface to dry. Completely dried decorative finishing can be painted (best of all - with special paints for facade work) or coated with a colorless protective agent.

This is the technology used to apply plaster on polystyrene foam. We hope the information was useful to you.

Summing up

Now you know how to plaster walls. In order to more accurately understand the technological and practical issue, our website provides detailed photo and video instructions in which you will find the necessary information on this issue.

Finishing the facade with foam plastic is a method that many homeowners use to insulate their homes. But such a thermal insulation layer needs to be protected from the effects of the external environment and accidental mechanical damage.

Facade plaster will help solve this problem, which will not only preserve the integrity of the insulation, but also improve the thermal insulation of the building.

What materials should I use for plastering?

Considering that polystyrene foam has a smooth and even surface, it is better to choose plasters designed specifically for finishing this material, since not every solution will reliably adhere to such a base.

For more information about facade plaster on polystyrene foam, watch the video:

As an option, you can use universal mixtures Ceresit or Ecomix, as well as any other compositions that have high-quality adhesion to polystyrene materials.

Suitable as facade plaster the following mixtures:

mineral mortars made on the basis of slaked lime, white Portland cement and light fillers. Such plasters have high strength, good adhesion, as well as antibacterial properties, which prevents the formation of mold and mildew under the mortar layer;
acrylic mixtures. This coating has a longer service life compared to the previous composition, but at the same time has insufficient vapor permeability, which prevents the formation of a microclimate indoors. The material is produced in the form of a ready-made water-dispersion mixture;
silicone compounds. They are produced on the basis of liquid glass, which makes them resistant to aggressive environmental conditions. Thanks to this, silicone plaster is a good protection for insulation, but such material is not cheap;
cement-sand plaster. The advantages of this option are high vapor permeability and low cost of raw materials. The downside is the lack of elasticity of the finished mixture.

Installation of reinforcing mesh

In order for the applied solution to adhere well to the surface when plastering polystyrene foam, a reinforcing layer should be laid on top of the material, using a special PVC mesh for this.

For exterior work, a facade mesh is suitable, which has sufficient density, due to which the layer of plaster will lie more evenly on the surface. But here you also need to take into account that a mesh that is too dense will create some difficulties when working with corners.

The best option in this case is a canvas with a density of 140-160 g/m2. Also, when plastering with cement-based mortar, it is better to use an alkali-resistant mesh.

Recently, the implementation of concrete floor screed has become much easier, which is associated with the advent of dry concrete mixtures. for floor screed - this is quality, popularity and availability.

Wall finishing, which is carried out outside, plays a huge role and is considered one of the main stages of work. have special properties, as they produce a heat effect and also guarantee high-quality sound insulation.

When planning a renovation, it is important to take into account not only how much material is required for the work, but how long it will take. Find out how long it takes for a floor screed to dry.

If a universal mixture is used as plaster, then the reinforcing sheet is attached using this solution. When using other compositions, the mesh can be secured with glue specially designed for reinforcement.

There are several ways to glue the canvas:

the material is applied to the foam and coated with the solution on top. The mixture, penetrating through the cells, glues the mesh to the base. It is inconvenient to do such work yourself (without a partner), since you will need to hold the mesh with one hand and apply the solution with the other;
in this case, you can use temporary fasteners (screws);
the mixture is applied to the surface to be treated, after which a mesh is applied to the wall and pressed into the solution with a spatula.

The reinforcement process begins with the corners of the building, door and window slopes, after which the plane is finished.

The entire procedure is performed as follows:

the mesh is cut into pieces 30-40 cm wide. The length of the segments is determined based on the size of the slopes, and meter-long sheets are prepared for processing the corners. Before installation, it is advisable to bend the cut strips to form a rib;
then a layer of mortar about 3 mm thick is applied to the corners and slopes, after which the mesh is pressed into it and smoothed out with sideways movements;
after this, the reinforcing fabric is cut into strips 1 m long and 0.9 m wide. The material cut into pieces is easier to install, whereas when laying large sizes, the solution may dry out before the fabric is completely smoothed;
The mixture is applied with a wide spatula, pieces of mesh are mounted vertically overlapping, with an overlap of 15 cm.

After the adhesive has dried (depending on the weather, this can take from several hours to a day), the surface must be rubbed using a trowel or plastic float with sandpaper attached to it.

The tool is moistened in water and the plaster is rubbed in a circular motion, thereby removing irregularities and depressions.

Applying a leveling layer

It is done in the following way: perform plastering using a wide spatula (350-400 mm) or using beacons and a rule. The second option is a reliable way to obtain a flat surface, which can be difficult to achieve with other methods without sufficient experience.

The leveled beacons are attached to the wall with self-tapping screws. The distance between them must be less than the length of the rule. The solution is poured onto the surface and smoothed using the rule, relying on the installed guides.

When finishing with a spatula, the mixture is applied to the wall with smooth movements and leveled over the surface. If it was not immediately possible to achieve a smooth surface, then after drying you should apply another layer. After high-quality grouting, it will be enough to apply a layer 3 mm thick.

The dried surface is rubbed using the same principle as the mesh.

Final works

The last stage of plastering foam plastic is the creation of a decorative layer, before applying which the rough surface is primed using a fine-pile roller.

“” or “wet” plaster technology is often used as a finishing finish. They are applied using a spatula and grater. The thickness of the decorative layer depends on the size of the granules included in the mixture. The larger the granules, the thicker the finish coat will be.

The finished surface is left to dry completely, after which it is painted in the desired color.

High-quality foam plaster is the key to the durability of the coating and the preservation of the aesthetic appearance of the structure. Therefore, it is best to use special ready-made mixtures here. But if the budget does not allow you to resort to the most effective methods, then you can get by with ordinary cement-sand mortar.

The main thing in this case is to adhere to the correct technology for preparing the solution (1:3 plus 70 g of PVA glue per 10 liters of plaster), bringing it to the desired (creamy) consistency.