Every year, thermal insulation of the facade with foam plastic becomes the most popular method of insulating houses and buildings. But with all its advantages, expanded polystyrene must be protected from external influences of climatic and biological factors. With this task, it copes well with foam plastic, provided that all work is done competently.
If you have chosen expanded polystyrene or foam plastic as a facade insulation, there will be a need for high-quality plastering of the thermal insulation surface. Below is a detailed discussion of how to properly plaster a building, protecting its thermal insulation from the harmful effects of natural and atmospheric phenomena.
Styrofoam plaster 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 on the facade grid.
- Uniform processing of the facade with plaster.
- Rubbing a uniform layer of plaster.
- Priming work.
- Final decorative.
Plaster preparation
For the processing of expanded polystyrene, foam plastic and other similar building materials for insulation, different types of plaster solutions are used.
Due to the 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 ratio with their quality.
It is important to know: when plastering a certain building, you need to use a mortar or mixture from only one manufacturer.
Not all manufacturers of plaster mortars produce one mixture for the treatment of thermal insulation of facades. There are manufacturers who make a separate solution for gluing the plaster mesh to the wall and a separate mixture for facade processing of insulation.
When purchasing a separate mixture for gluing the mesh, make sure that the plaster for processing the thermal insulation of the facade belongs to the same manufacturer.
Approximately 3.5 kg/m2 of mortar is required for gluing the plaster mesh, and the mixture consumption for uniform processing of the entire facade is 5.5 kg/m2. When creating a solution, be sure to observe the desired proportions, which are displayed by the manufacturer on the package itself.
Experts recommend mixing a mortar that is slightly thinner than the manufacturer's recommended mix. This will not affect the quality of the plaster itself and will create more comfortable conditions for its application during finishing work. In particular, the layer intended for even treatment of the façade must be thinned. The degree of liquefaction can be determined by focusing on the level of runoff 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 plaster on the expanded polystyrene will be attached.
Preparation and pasting of the facade with a plaster mesh
When preparing plaster over Styrofoam, it is imperative to adapt it to self-retain on the covering of the wall you are about to process.
Without it is impossible to securely stick 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 outdoor facade work, the density of which should be at least 150 g / m2. The most dense mesh will contribute to uniform processing of the facade covering, but it is worth considering the difficulty that arises when pasting decorative elements and corners. These areas can be processed with a network with reduced density.
It is important to know: due to the fact that foam plaster is most often done on a cement basis, it is necessary to select an alkali-resistant mixture.
Gluing the facade mesh should begin with corners, arches, window and door slopes, as well as other difficult-to-work areas:
- To glue the facade mesh in the corner sections, it is necessary to cut a corbel from the mesh 30 cm wide and 1 m long (the length for the slope or arch is determined by measuring the required area yourself).
- The belt must be bent right in the center so that when unbending, the fold line is clearly visible.
- The plaster mortar is applied to the corner areas with a spatula, its density must be at least 2 mm.
Attach the mesh to the covering of the desired section of the facade and, pressing down with a spatula, smooth it out with gentle movements, starting from the corner to the underside.
After successfully gluing all difficult-to-process areas, you can start gluing the facade mesh to the flat sections 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 piece of a longer length due to the quick-drying properties of the plaster mortar. If you are sure that you will manage on time, you can cut off pieces of a larger size, but it is recommended not to risk it, otherwise there is a chance of spoiling the building materials.
The plaster mixture is applied to the treated area of the wall with a layer of at least 3 mm, oriented to the size of the prepared mesh section.
When attaching the mesh, press it with a spatula and smooth it out, 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 mounting the grid in the same row, moving to the right or left side. Pasting of a front grid is carried out with an overlap. In the same way, edge joints are glued, as well as slopes, arches and corners.
Important to know: pay special attention to the joints, corners and decorating elements of the facade, otherwise they will look sloppy even after the final exterior finish.
Facade mesh rubbing
The glued mesh must be rubbed evenly without fail. This is done using a plastic grater with sandpaper.
Mashing is carried out exclusively on a dried solution. Usually it takes a little time, for example, in the summer it will dry in just 4-5 hours. In cooler seasons, it is recommended to wait about 20-22 hours before grouting.
It is necessary to carry out mashing with gentle movements in a circle, preferably counterclockwise. Be sure to change the sandpaper if it gets wet solution.
Uniform processing 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 mortar of plaster is applied to a large spatula, which must be evenly covered with a facade wall. The thickness of the layer is selected based on the quality of the wall processing. 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 should be taken into account that the mesh joints should not fall on the joints of the aligned sections.
Applying an even layer of plaster
Rubbing a uniform layer is carried out according to the same method as rubbing along the facade grid.
It is important to know: mashing a uniform layer must be done no earlier than 20-22 hours and no later than 4 days after processing the facade. In the case of late grouting, you will have to make 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 decorative plaster will be applied precisely to this surface.
Priming work
In order for the fine finish to be well kept on a uniform layer, it is necessary to prime it. Quartz primer (CT-16) is excellent for decorative plaster. In the case of normal façade painting, a quartz-free primer must be used to maintain an even finish (CT-17). When choosing a primer, you should pay attention to the Ceresit brand, since its price is about 450 rubles. and it correlates well with the quality of the product.
The primer must be applied with a short-haired roller to avoid streaks.
Having finished the priming work, you can proceed to the final finishing of the facade of the building.
Final decorative finishing of the facade with plaster
The final finishing of the facade must be carried out by applying the main layer of plaster on a spatula. Its thickness is determined based on the size of the mineral grains in the content of the solution: the finer the grains, the thinner the layer. Make sure that the layer is evenly applied over the surface area of the facade wall.
The base layer must be leveled with a large-pored sponge or float, while at the same time forming the desired decorative elements of the facade. Allow the plaster to dry before painting the façade or applying a protective solution.
This guide will help you to process the Styrofoam insulation with plaster yourself. The omission of at least one of the stages does not guarantee successful processing and durability of the facade of the building.
Expanded polystyrene, both ordinary and extruded, has become widely used as an insulating material. Its use is caused by an affordable price and excellent heat-insulating properties.
The correct use of this material (fixing it on the walls outside the house) allows you to keep warm, prevent the formation of mold and fungus inside the premises.
To protect the insulation itself from the destructive effects of the external environment, plaster on expanded polystyrene is used. In this way, you can extend its life several times.
Why is it necessary to plaster polystyrene foam?
Plaster will protect the material from destruction Plaster is an important element of protective treatment. in this case, it differs in a number of nuances from ordinary plaster. Styrofoam is characterized by the presence of a porous structure. This material is produced by filling styrene granules with gas under the influence of high pressure and heating with water vapor. Exposure to high pressure and temperature leads to swelling and sticking of the granules to each other.
After that, the mass of the obtained substance is pressed, giving it the shape of plates. The thermal insulation performance of the resulting material is high, but it worsens the natural ventilation in the house. Low cost compared to other heaters and low weight make it possible 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 plate begins to crumble and may crumble into pieces.
In connection with these phenomena, it is required to apply a plaster coating on expanded polystyrene. It plays a protective role against negative influences.
Along with conventional foam plastic, the use of fire-resistant and extruded polystyrene foam types 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 does not allow steam and water to penetrate into the structure. The negative effects of the atmosphere can be traced only on the surface, but also in the places of cuts, so the use of extruded polystyrene foam in the long term is more preferable.
Applied tools and materials
To , you need to use a specific set of tools. The necessary tools and their purpose are described in the table.
| № | Instrument name | Purpose |
|---|---|---|
| 1 | construction mixer | designed to stir the solution to the desired consistency; |
| 2 | set of spatulas | used to apply the mixed composition to the work surface; |
| 3 | construction grater | removal of minor irregularities, grinding; |
| 4 | set of containers | under water, for solution; |
| 5 | construction knife, hacksaw | cutting boards and fiberglass mesh, notching; |
After preparing the tools, the question arises of choosing a plaster. The offered materials differ in price and composition. For finishing work, special plaster (facade) on expanded polystyrene is required.
Its most common types with a brief description are presented in the following table.
| № | 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 designed specifically for finishing insulated facades); extruded foam is not particularly required to be prepared for plastering; fits well on the treated surface; allow you to create decorative elements, textured images on the facade |
Choose fire resistant mixtures This is not a complete list. Modern manufacturers offer a large selection. Some samples may differ in only one or two of their constituent components.
The mixtures of the companies Knauf, Ceresit, Polirem, Kreisel (for example, the brands of universal adhesives CeresitCT-85№, Coral SP-141, PoliminP-19) have gained particular popularity.
When choosing, you should pay attention to the refractory properties of the compositions, because for the most part polystyrene foams have an average degree of flammability, it is recommended to use plaster materials that are more resistant to fire.
The plaster is produced for sale (mainly) in bags from 15 to 25 kg in weight.
It is not recommended to perform plaster work with a solution of cement and sand. Such surfaces will not last long.
The mesh will strengthen the mixture on the wall You will also need water and fiberglass mesh (prevents cracking, holds plaster).
- according to the consumption data indicated on the packaging per 1 sq. m. of the treated surface;
- purchase (approximately) mixtures for one wall;
- after plastering, calculate the practical consumption and buy in addition to the desired area.
Features of working with extruded polystyrene foam
Plastering of extruded polystyrene foam in connection with its physical indicators has a number of differences.
The most characteristic and showing the nuances of working with this material are the following properties:
- moisture is not absorbed into the insulation boards, so all the water from the facade remains inside the finishing layer;
- the expansion coefficient of (temperature) foam plastic does not correspond to this indicator for plaster mixtures, therefore, due to temperature differences, the coating applied to the plates may crack and fall off;
- the surface of the insulation is smooth, dense, irregularities and micropores are almost absent, which makes it difficult for the solution to adhere to it.
If the material is too smooth, it is roughened Before starting work, it is required to apply a small amount of plaster mortar on the stove and wait a day. If the coating was applied with difficulty, cracked or fell off after drying, then additional processing of the contact layer should be carried out.
It consists in increasing the roughness of the interacting part of the plate using a spiked roller or small plastic brushes. After that, a special primer, reinforcing mesh should be applied. The latter is fastened either with a special adhesive composition, or left over from work with insulation.
Due to the low adhesion and weak adhesion, the thickness of the applied mortar layers should not exceed 3 mm.
Extruded polystyrene foam requires a different plastering technology from the standard process.
Process Technology
Apply two coats of plaster Styrofoam plaster is performed in two layers: 1st - creates a reinforcing mesh coating, 2nd - levels the surface. The work is carried out in several successive stages:
- to increase the degree of adhesion between materials, notches are made on the surface of the plates (using a hacksaw or a needle roller in increments of about 5 cm);
- from the beginning, the door and window openings of the building, its corners are reinforced with a fiberglass mesh;
- full mortar coverage of the reinforced wall;
- mashing the first layer;
- applying the second plaster layer;
- final (final) grout;
- primer for finishing. For more information about plastering, see 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 a width of about 30 cm. They are bent in half and tried on at the corner (opening).
For the grid, following the instructions on the package, one bucket of solution is made (in order to have time to work out before drying begins). It is applied with a spatula on both sides of the corner (10 cm on each side of the corner). The remaining 5 cm untreated is needed to overlap 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. For corners, a ready-made mesh profile is also used.
Then the entire wall is reinforced: the mesh is pressed into the solution, covered with a layer of plaster. Work quickly so that the mortar sets. Grid joints should not coincide with the joints of insulation sheets.
When the plastered surface dries (it will take about 2 hours), then it is rubbed with a special grater using circular movements, which must be periodically moistened with water. Slight roughness should be left for better adhesion to the second layer. For more information about the finishing of expanded polystyrene, see this video:
The final 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. Works are carried out in warm (above 5 degrees) calm weather.
You can do the work yourself. The main condition for obtaining a quality result is the use of suitable compositions and compliance with the technology of work.
Every year, thermal insulation of the facade with foam plastic becomes the most popular method of insulating houses and buildings. But with all its advantages, expanded polystyrene must be protected from external influences of climatic and biological factors. Facade plastering on foam plastic copes well with this task, provided that all work is done correctly.
If you have chosen expanded polystyrene or foam plastic as a facade insulation, there will be a need for high-quality plastering of the thermal insulation surface. Below is a detailed discussion of how to properly plaster a building, protecting its thermal insulation from the harmful effects of natural and atmospheric phenomena.
Styrofoam plaster 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 on the facade grid.
- Uniform processing of the facade with plaster.
- Rubbing a uniform layer of plaster.
- Priming work.
- Final decorative finishing of the facade with plaster.
Plaster preparation
For the processing of expanded polystyrene, foam plastic and other similar building materials for insulation, different types of plaster solutions are used.
Due to the 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 ratio with their quality.
It is important to know: when plastering a certain building, you need to use a mortar or mixture from only one manufacturer.
Not all manufacturers of plaster mortars produce one mixture for the treatment of thermal insulation of facades. There are manufacturers who make a separate solution for gluing the plaster mesh to the wall and a separate mixture for facade processing of insulation.
When purchasing a separate mixture for gluing the mesh, make sure that the plaster for processing the thermal insulation of the facade belongs to the same manufacturer.
Approximately 3.5 kg/m2 of mortar is required for gluing the plaster mesh, and the mixture consumption for uniform processing of the entire facade is 5.5 kg/m2. When creating a solution, be sure to observe the desired proportions, which are displayed by the manufacturer on the package itself.
Experts recommend mixing a mortar that is slightly thinner than the manufacturer's recommended mix. This will not affect the quality of the plaster itself and will create more comfortable conditions for its application during finishing work. In particular, the layer intended for even treatment of the façade must be thinned. The degree of liquefaction can be determined by focusing on the level of runoff 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 plaster on the expanded polystyrene will be attached.
Preparation and pasting of the facade with a plaster mesh
When preparing plaster over Styrofoam, it is imperative to adapt it to self-retain on the covering of the wall you are about to process.
Without a facade mesh, plaster cannot be reliably glued 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 outdoor facade work, the density of which should be at least 150 g / m2. The most dense mesh will contribute to uniform processing of the facade covering, but it is worth considering the difficulty that arises when pasting decorative elements and corners. These areas can be processed with a network with reduced density.
It is important to know: due to the fact that foam plaster is most often done on a cement basis, it is necessary to select an alkali-resistant mixture.
Gluing the facade mesh should begin with corners, arches, window and door slopes, as well as other difficult-to-work areas:
- To glue the facade mesh in the corner sections, it is necessary to cut a corbel from the mesh 30 cm wide and 1 m long (the length for the slope or arch is determined by measuring the required area yourself).
- The belt must be bent right in the center so that when unbending, the fold line is clearly visible.
- The plaster mortar is applied to the corner areas with a spatula, its density must be at least 2 mm.
Attach the mesh to the covering of the desired section of the facade and, pressing down with a spatula, smooth it out with gentle movements, starting from the corner to the underside.
After successfully gluing all difficult-to-process areas, you can start gluing the facade mesh to the flat sections 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 piece of a longer length due to the quick-drying properties of the plaster mortar. If you are sure that you will manage on time, you can cut off pieces of a larger size, but it is recommended not to risk it, otherwise there is a chance of spoiling the building materials.
The plaster mixture is applied to the treated area of the wall with a layer of at least 3 mm, oriented to the size of the prepared mesh section.
When attaching the mesh, press it with a spatula and smooth it out, 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 mounting the grid in the same row, moving to the right or left side. Pasting of a front grid is carried out with an overlap. In the same way, edge joints are glued, as well as slopes, arches and corners.
Important to know: pay special attention to the joints, corners and decorating elements of the facade, otherwise they will look sloppy even after the final exterior finish.
Facade mesh rubbing
The glued mesh must be rubbed evenly without fail. This is done using a plastic grater with sandpaper.
Mashing is carried out exclusively on a dried solution. Usually it takes a little time, for example, in the summer it will dry in just 4-5 hours. In cooler seasons, it is recommended to wait about 20-22 hours before grouting.
It is necessary to carry out mashing with gentle movements in a circle, preferably counterclockwise. Be sure to change the sandpaper if it gets wet solution.
Uniform processing 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 mortar of plaster is applied to a large spatula, which must be evenly covered with a facade wall. The thickness of the layer is selected based on the quality of the wall processing. 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 should be taken into account that the mesh joints should not fall on the joints of the aligned sections.
Applying an even layer of plaster
Rubbing a uniform layer is carried out according to the same method as rubbing along the facade grid.
It is important to know: mashing a uniform layer must be done no earlier than 20-22 hours and no later than 4 days after processing the facade. In the case of late grouting, you will have to make 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 decorative plaster will be applied precisely to this surface.
Priming work
In order for the fine finish to be well kept on a uniform layer, it is necessary to prime it. Quartz primer (CT-16) is excellent for decorative plaster. In the case of normal façade painting, a quartz-free primer must be used to maintain an even finish (CT-17). When choosing a primer, you should pay attention to the Ceresit brand, since its price is about 450 rubles. and it correlates well with the quality of the product.
The primer must be applied with a short-haired roller to avoid streaks.
Having finished the priming work, you can proceed to the final finishing of the facade of the building.
Final decorative finishing of the facade with plaster
The final finishing of the facade must be carried out by applying the main layer of plaster on a spatula. Its thickness is determined based on the size of the mineral grains in the content of the solution: the finer the grains, the thinner the layer. Make sure that the layer is evenly applied over the surface area of the facade wall.
The base layer must be leveled with a large-pored sponge or float, while at the same time forming the desired decorative elements of the facade. Allow the plaster to dry before painting the façade or applying a protective solution.
This guide will help you to process the Styrofoam insulation with plaster yourself. The omission of at least one of the stages does not guarantee successful processing and durability of the facade of the building.
How to properly finish the facade on foam using facade plaster
The simplest and most affordable option for insulating the facade of a building is the use of foam. The material is not only very resistant to external damage, but also perfectly tolerates exposure to a humid environment and ultraviolet radiation.
Unfortunately, during the installation of foam, even with high-quality work, gaps form between the foam sheets, 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 the purchase of special finishing materials.
This will help the usual facade plaster on the facade. The material has an affordable cost and allows you to finish the walls of the building in the shortest possible time. Consider all issues related to the design of the building, thus, in more detail.
Facade plaster - advantages and disadvantages
Plastering walls finished with foam, cannot be carried out with ordinary plaster. This is fraught with the fact that after drying, the mixture may simply fall off and the plastering will have to be carried out again.
In this regard, it is extremely important to choose the right plaster that fits well on the foam and can last a long period of time. Consider which plasters are suitable for this purpose and will be the most suitable.
Before making a choice of plaster, we will 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 a facade plaster designed to work with foam.
Experienced craftsmen recommend using well-known and popular brands of finishing compositions Ekomiks and Ceresit, however, it is worth noting that absolutely any plaster can be used that has high adhesive performance in relation to polystyrene materials. The most important thing is to use a mixture from one manufacturer on the entire work surface to be plastered and do not mix compositions of different brands.
The next thing you need to pay attention to is that some manufacturers recommend the use of compositions for gluing foam, followed by the application of 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.
For finishing facades, plasters are best suited:
If we talk about the cost, then the most expensive compositions are polymeric, however, they are the most durable and do not crack during application, as well as after drying. There are practically no drawbacks to each type of plaster, and buyers should choose the composition, focusing 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
Let us consider in more detail what types of plasters are suitable 
for application to foam.
Since we are talking about exterior decoration, then plaster must tolerate low and high temperatures well, as well as various atmospheric phenomena.
In this regard, gypsum compositions should immediately be excluded from the list of suitable mixtures.
So, we have already noted that the best option would be cement or polymer compounds, but not those that are prepared by mixing cement, sand and water at home, but which are sold in hardware stores.
The thing is that additional components are added to the special compositions, which provide the plaster with strength and durability. Consider which compositions are most preferred for application to the foam.
There are the following types of compositions:
- Mineral. Sand, water and cement are used to create them. They do not differ in durability, but have a small cost.
- Acrylic. The mixtures are based on acrylic resins. The material perfectly passes air and allows the material inside to “breathe”. Differs in high vapor permeability.
- silicate. They sell such plaster in buckets, and it is characterized by an alkaline reaction. You need to work with it very carefully.
- Silicone. They have increased elasticity and form a uniform beautiful layer when applied.
In addition to varieties, there are several 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 compounds are characterized by increased resistance to the appearance of mold, fungi and algae.
Consumption of facade plaster on foam plastic
For plastering the facade of a building finished with foam, 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 a decision is made 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 such an indicator 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.
Surface preparation for application
Before you start plastering walls finished with foam, it is very important to properly prepare the work surface. For this purpose, you will need:
- close the seams between sheets with the help of mounting foam and wait for it to dry;
- if surpluses are formed, then they must be cut off with a sharp knife;
- most often, the foam is attached with the help of "umbrellas", therefore 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 that, you will need to sweep the surface of the wall from dust and primed. 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 moment, because, after applying the plaster, ugly cracks may form on it.
Reinforcement and priming
Reinforcing or applying 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 a plaster solution from above.. The composition penetrates into the cells and the material is quickly glued. It is not easy to do this 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 fix the mesh first and then apply the solution.
- The second way is to first apply plaster to a section of the wall, and then attach a grid 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, is glued to its destination. After the plaster dries, and this may take from several hours to a day, it should be rubbed with sandpaper or a special grater to eliminate various irregularities.
After that, the surface of the walls is primed with a special compound that enhances the protective functions and qualities of the plaster itself. It is better to choose a liquid homogeneous primer, which will roughen the coating and provide better adhesion of the material.
The technology of finishing the facade with plaster on foam plastic
The last stage of finishing 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 decoration of the walls - painting or coating 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.
Finishing should be especially careful and accurate when it comes to subsequent painting, since all the irregularities in the future will only be emphasized by the paint and the walls will not take on a very aesthetic appearance.
In order for the surface to be perfectly smooth, after the coating has dried, it is recommended to grind it with sandpaper or a special mesh. It is important to grout in the first 3-4 days, otherwise in the future, the composition will harden strongly and it will be extremely difficult to grind it.
An exception in this case is textured finishing plaster, however, everything here depends on the grain size.
Useful video
Master class on wall insulation with foam plastic and applying plaster:
Conclusion
In the prepared article, we tried to show how to choose and apply facade plaster on the walls of a building insulated with foam plastic. If you decide to cope with this task on your own, 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 extend the life of the building.
The procedure for plastering polystyrene foam
Expanded polystyrene, both ordinary and extruded, has become widely used as an insulating material. Its use is caused by an affordable price and excellent heat-insulating properties.
The correct use of this material (fixing it on the walls outside the house) allows you to keep warm, prevent the formation of mold and fungus inside the premises.
To protect the insulation itself from the destructive effects of the external environment, plaster on expanded polystyrene is used. In this way, you can extend its life several times.
Why is it necessary to plaster polystyrene foam?
Plaster is an important element of protective treatment. The technology of work in this case differs in a number of nuances from ordinary plaster. Styrofoam is characterized by the presence of a porous structure. This material is produced by filling styrene granules with gas under the influence of high pressure and heating with water vapor. Exposure to high pressure and temperature leads to swelling and sticking of the granules to each other.
After that, the mass of the obtained substance is pressed, giving it the shape of plates. The thermal insulation performance of the resulting material is high, but it worsens the natural ventilation in the house. Low cost compared to other heaters and low weight make it possible 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 plate begins to crumble and may crumble into pieces.
In connection with these phenomena, it is required to apply a plaster coating on expanded polystyrene. It plays a protective role against negative influences.
Along with conventional foam plastic, the use of fire-resistant and extruded polystyrene foam types 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 does not allow steam and water to penetrate into the structure. The negative effects of the atmosphere can be traced only on the surface, but also in the places of cuts, so the use of extruded polystyrene foam in the long term is more preferable.
Applied tools and materials
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. Tool name Purpose 1 construction mixer is designed to stir the mortar to the required consistency; 2 set of spatulas is used to apply the mixed composition to the work surface; 3 construction float removal of minor irregularities, grinding; 4 set of containers for water, for solution; 5 construction knife, hacksaw cutting plates and fiberglass mesh, notching;
After preparing the tools, the question arises of choosing a plaster. The offered materials differ in price and composition.
For finishing work, special plaster (facade) on expanded polystyrene is required.
Its most common types with a brief description 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 the main components are acrylic resins, chemical additives;
excellent quality (they are designed specifically for finishing insulated facades);
extruded foam is not particularly required to be prepared for plastering;
fits well on the treated surface;
allow you to create decorative elements, textured images on the facade
Choose fire resistant mixtures
This is not a complete list. Modern manufacturers offer a large selection. Some samples may differ in only one or two of their constituent components.
The mixtures of the companies Knauf, Ceresit, Polirem, Kreisel (for example, the brands of universal adhesives CeresitCT-85№, Coral SP-141, PoliminP-19) have gained particular popularity.
When choosing, you should pay attention to the refractory properties of the compositions, because for the most part polystyrene foams have an average degree of flammability, it is recommended to use plaster materials that are more resistant to fire.
The plaster is produced for sale (mainly) in bags from 15 to 25 kg in weight.
It is not recommended to perform plaster work with a solution of cement and sand. Such surfaces will not last long.
You will also need water and fiberglass mesh (prevents cracking, holds plaster).
- according to the consumption data indicated on the packaging per 1 sq. m. of the treated surface;
- purchase (approximately) mixtures for one wall;
- after plastering, calculate the practical consumption and buy in addition to the desired area.
Features of working with extruded polystyrene foam
Plastering of extruded polystyrene foam in connection with its physical indicators has a number of differences.
The most characteristic and showing the nuances of working with this material are the following properties:
- moisture is not absorbed into the insulation boards, so all the water from the facade remains inside the finishing layer;
- the expansion coefficient of (temperature) foam plastic does not correspond to this indicator for plaster mixtures, therefore, due to temperature differences, the coating applied to the plates may crack and fall off;
- the surface of the insulation is smooth, dense, irregularities and micropores are almost absent, which makes it difficult for the solution to adhere to it.
If the material is too smooth, it is roughened
Before starting work, it is required to apply a small amount of plaster mortar on the stove and wait a day. If the coating was applied with difficulty, cracked or fell off after drying, then additional processing of the contact layer should be carried out.
It consists in increasing the roughness of the interacting part of the plate using a spiked roller or small plastic brushes. After that, a special primer, reinforcing mesh should be applied. The latter is fastened either with a special adhesive composition, or left over from work with insulation.
Due to the low adhesion and weak adhesion, the thickness of the applied mortar layers should not exceed 3 mm.
Extruded polystyrene foam requires a different plastering technology from the standard process.
Process Technology
Styrofoam plaster is carried out in two layers: 1st - creates a reinforcing mesh coating, 2nd - levels the surface. The work is carried out in several successive stages:
- to increase the degree of adhesion between 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, its corners are reinforced with a fiberglass mesh;
- full mortar coverage of the reinforced wall;
- mashing the first layer;
- applying the second plaster layer;
- final (final) grout;
- primer for finishing. For more information about plastering, see this video:
The mortar 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 a width of about 30 cm. They are bent in half and tried on at the corner (opening).
For the grid, following the instructions on the package, one bucket of solution is made (in order to have time to work out before drying begins). It is applied with a spatula on both sides of the corner (10 cm on each side of the corner). The remaining 5 cm untreated is needed to overlap 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. For corners, a ready-made mesh profile is also used.
Then the entire wall is reinforced: the mesh is pressed into the solution, covered with a layer of plaster. Work quickly so that the mortar sets. Grid joints should not coincide with the joints of insulation sheets.
When the plastered surface dries (it will take about 2 hours), then it is rubbed with a special grater using circular movements, which must be periodically moistened with water. Slight roughness should be left for better adhesion to the second layer. For more information about the finishing of expanded polystyrene, see this video:
The final 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. Works are carried out in warm (above 5 degrees) calm weather.
You can do the work yourself. The main condition for obtaining a quality result is the use of suitable compositions and compliance with the technology of work.
Extruded polystyrene foam plaster: how and how to plaster polystyrene foam
Today, everyone is engaged in the insulation of their homes. This is a necessary measure to save energy sources in general and money in a particular family. Therefore, almost everyone was engaged in the study of technologies and materials for creating a heat-insulating layer.
Most sources mention that polystyrene foam must be plastered. Why and how to do this, we will figure it out 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 at all and are destroyed when exposed to factors such as:
- solar radiation;
- some period of operation;
- Atmosphere pressure.
Even the new material is very fragile. If you hit an unprotected plate, a dent is formed, and the corners are already easily broken.
That 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 qualitatively and quickly apply a plaster solution to polystyrene foam, you will have to acquire a set of tools. For this you need:
- Containers for mixing solution.
- Perforator (used both for preparing the mixture and for fixing polystyrene foam).
- Brush or spray gun for applying primer.
- Sharp knife for cutting reinforcing mesh and insulation boards.
- Wide spatula for applying mortar to the surface.
- Narrow spatula.
- Grater for leveling the layer.
It is unlikely that everyone will have such a set, therefore, when going for materials, do not forget to purchase tools right away.
Types of plaster materials
This material requires the selection of a special plaster composition. Not all plasters are suitable for Styrofoam. Some options contain components that destroy the foam immediately. Therefore, in the store, be sure to check with the consultant whether the composition for work on this heater will go 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 mixes, 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 on your own. At the same time, sand, cement are bought 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 serving for finishing 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 notches are made over the entire surface.
Acrylic
A more expensive option for plaster mixtures, but at the same time of better quality. Such plaster on expanded polystyrene does not require special preparatory work, since it has high adhesion rates with 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 form grooves after mashing. Using different grouting techniques, you can create an original pattern.
Features of this finish
It is difficult to apply plaster on this insulation for the following reasons:
- smooth surface - the solution can slip, if you still manage to apply it, then 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 prolongs the drying time;
- the difference in the values of thermal expansion of the insulation and the 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 expanded polystyrene with a needle roller or make notches with a sharp knife. Thus, recesses are obtained where the solution can “catch”.
- Be sure to coat 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 the insulation boards are installed on the walls of the building, it is necessary to close them with a finish as soon as possible. Professionals recommend doing this immediately after the glue on which the material was fixed dries.
Carrying out calculations
It is better to buy material for plastering with a margin. I would not want to run for an additional bag in the midst of work. But how do you know how much material you need? To do this, carry out a simple calculation:
- calculate the area of the treated walls without taking into account window and door openings;
- on the packaging, the approximate consumption of the mixture per square meter is indicated. For different compositions, it ranges from 4–6 kg;
- multiply the specified value by the cultivated area and get the required amount of the mixture;
- 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 read the packaging and recommendations. If you are plastering Styrofoam for the first time, do a little kneading first to get used to the mortar and the execution process.
- Pour the dry mixture into the container.
- Water is added in small portions.
- You can mix by hand, use a hammer drill with a nozzle or a construction mixer.
- When the consistency is completely satisfied, leave the solution for 5 minutes to ripen and mix 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 both sides of the corner have 10-15 cm of material.
- a thin layer of mortar is applied on both sides of the corner;
- apply a mesh and smooth from the corner so that the material is completely deep into the solution;
- if the length of the piece was not enough, make an overlap of 10 cm, it is impossible to glue it into the joint.
- The wall is covered with mortar.
- The width of the strip slightly exceeds the size of the reinforcing mesh.
- Apply the material and smooth with a wide spatula or trowel.
- The next layer of the mesh overlaps the previous one by 10–15 cm.
Grouting plaster mesh
The first layer must dry completely. After that, with a grater with sandpaper, with light circular movements, the surface is treated. This will remove small bumps and help you use less leveling mortar.
Surface leveling
We are preparing a new solution and proceed to leveling the plastered polystyrene foam. Now work with a wide spatula:
- a small amount of solution is collected on a wide spatula;
- arc movements from top to bottom are applied to the wall;
- layer thickness no more than 3 mm.
Make sure the surface is as flat as possible.
Grouting the second layer
Start grouting only after the layer is completely dry. They work with the same grater with sandpaper. Only be sure to pick up fine grain to remove small flaws. Otherwise, you can just spoil the whole work.
Primer
This step should not be neglected. If you do not cover the base with a primer, then the decorative layer will either be poorly applied or quickly lose its attractiveness. The composition of the primer depends on the method of finishing:
- Further decorative plastering - a composition is used in which there is quartz sand, it helps to increase adhesion.
- Staining - composition without sand, makes the base even smoother.
Finishing
Having chosen one or another method of finishing, 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 right.
Prices for services and materials
If the owner plans to do all the work on his own, then only materials will be included in his costs. Need to buy:
- Expanded polystyrene - thickness 50 mm from 110 rubles / pack.
- Glue for foam plastic - from 350 rubles / bottle or from 420 rubles / 25 kg of dry mix.
- Fiberglass reinforcing mesh - from 780 rubles / roll.
- Facade plaster - from 250 rubles / 25 kg.
And materials for decoration, either paint or decorative plaster. There is an option and hiring professional workers who will quickly do everything. Their cost depends on:
- storeys of the building. Finishing a private house will cost a little less than doing work at height;
- the materials will be purchased by the customer or they will take their own;
- total finishing area.
Styrofoam plastering technology
Expanded polystyrene is one of the most common materials for insulating external walls. It is correct to make insulation with polystyrene foam from the outside, 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, precipitation. Protection methods can be as follows:
- sheathing with siding panels;
- painting with rubber paint or varnish;
- Styrofoam plaster.
In this article we will talk about the last protection option - plaster. This type of protection has high strength, it is durable, and it has many decorative solutions.
Styrofoam plaster
Necessary materials
- Ready dry mix;
- Fiberglass mesh;
- Water.
For expanded polystyrene, a special facade plaster for expanded polystyrene is required. Most manufacturers have such mixtures. As a rule, dry mixes are put on sale in bags weighing 15-25 kg. It is not worth plastering polystyrene foam with an ordinary cement-sand mortar - even if you can plaster a wall, such plaster is not very durable.
The composition of ready-made dry mixes includes special additives, they help better adhesion of the mixture to the surface of expanded polystyrene.
Typically, the consumption of a mixture for plaster in 2 layers is approximately 4-6 kg per 1 square meter. We recommend purchasing material at a minimum based on one wall. When you plaster the first wall and count how many kilograms of the mixture it took, then you can determine the exact consumption of bags of plaster.
Fiberglass mesh is an indispensable material for polystyrene foam plastering. It holds the plaster and prevents cracking.
Cooking Tools
For work you need:
- spatula large;
- small spatula;
- building grater or semi-ter;
- knife cutter construction;
- hacksaw;
- containers for solution and water, respectively;
- construction mixer.
Plastering technology
Facade plaster on expanded polystyrene is applied in two layers:
- the first layer of plaster with mesh reinforcement;
- the second layer is leveling, fixing.
In this case, the work will take place in several stages.
Stages of facade insulation of the building
The first stage: we make notches on polystyrene foam
It is necessary to make notches for better adhesion of the solution to the surface of the polystyrene foam. This is especially important for extruded polystyrene foam, as 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 in width and press the fold with such force that after that the mesh retains its shape along the fold.
Dilute the solution from the finished mixture according to the instructions. The solution should be diluted no more than one bucket in order to always work with a fresh solution.
On both sides of the corner we apply the solution 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 the grid on the previous one, and we will rub them together in one layer of mortar. The thickness of the solution should be 2-3 mm.
We apply a strip of mesh to 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 remain without mortar, the principle is the same as along the length - in the future, we will overlap the next strip of the grid on the corner.
Now we press the grid with a spatula into the solution, starting from the top down and sideways. The plaster must completely cover the grid.
At the corners, you can use a finished profile with a grid
The third stage: plastering the wall completely
When all the corners and openings are reinforced, we reinforce the entire wall with a mesh.
We dilute the mixture according to the instructions, with a wide spatula we apply the solution to the polystyrene foam with a strip of 90 centimeters wide for the entire height of the floor. A solution of 90 cm is needed in order to leave 10 cm of the 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.
A strip of mesh prepared in advance, starting from the top, is pressed into the solution with a spatula, completely hiding it under the plaster. It is necessary to work quickly enough so that the solution does not have time to seize.
Thus, we reinforce the entire wall.
It is desirable that the mesh joints do not coincide with the joints of the expanded polystyrene sheets.
Fourth stage: overwrite 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 with water, that is, we wet it. The wall should not be rubbed too smoothly, it is necessary to leave roughness for adhesion of the second layer of plaster.
Fifth stage: the second layer of plaster
The next day, you can proceed to the final stage of plastering.
We prepare the solution fresh, apply it to the wall with a large spatula 2-3 mm thick. You can work with a grater or a trowel, whichever is more convenient for you. We leave the plaster to dry for several hours until it grabs a crust.
Sixth stage: finishing grout
We grout with a grater dipped in water, in the same way as in the fourth stage. Here you need to overwrite the plaster more carefully, preparing the surface for decorative finishing.
We warm the apartment
That's the whole technology of plastering polystyrene foam. 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;
- notches must be made on extruded polystyrene foam;
- the solution must be from a specially made plaster for expanded polystyrene.
Related videos
Having insulated the facade of the house, the owner is always faced with the unpresentable appearance of the insulation itself.
Since most often used as thermal insulation Styrofoam or penoplex, that is, a good way to help get rid of this problem is facade plaster on foam plastic. The application of any decorative layer will protect the insulation layer from the negative effects of the external environment.
INSULATION and PLASTERING WITH FOAM PLASTIC walls with your own hands
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Protective functions of plaster
If foam or foam plastic is chosen as a heater, then with constant exposure to moisture and the sun, the material will eventually become very fragile and become unusable. Also, everyone knows that this material can be easily damaged mechanically, that is, broken, scratched or pierced.
It is almost impossible to somehow fix these damages, you need to replace the whole area. If foam plaster is used, then it performs a number of protective functions, so that the insulation will last a very long time. A properly finished facade with plaster acts as a barrier against:
- The appearance of holes and dents due to mechanical damage.
- Exposure to high humidity.
- Sudden changes in temperature, as well as from prolonged exposure to heat or freezing.
- Fires. Styrofoam is highly flammable, but plaster will increase the level of fire safety.
How to choose plaster
In order to protect the insulation material, manufacturers suggest using special formulations designed for application to foam.
There are only two types of them - these are acrylic and cement-sand. Which is better the first or second facade plaster on expanded polystyrene, we will now figure it out.
Cement-sand
If we talk about the price, then cement-sand mixtures are much cheaper. And, of course, the most popular. But an attractive price does not give a long result.
Such a coating will last only 2-3 years and then the integrity of the layer will begin to collapse, as a result of which the insulation will suffer from the external environment.
In order not to have to re-install the heat-insulating layer, it is necessary to re-plaster it beforehand, removing the unsuitable coating. It must also be said that cement-sand mixtures are gray. To give a more presentable appearance to the coating, you need to use staining.
Acrylic
Acrylic mixes are much more expensive, but they will last much longer. In addition, they fit well on the base, you can choose already painted mixtures and at the same time you can make not only a smooth coating, but give it an interesting texture, for example, bark beetle, lamb or rain.
Given all the advantages and disadvantages of plaster mixtures, it should be said that it is better to choose acrylic as a decorative finish. They will last much longer and look much more attractive.
Training
After insulating the facade with foam, you need to carefully examine all the joints. If there are gaps somewhere, they must be closed with mounting foam or sealant. This will protect against the penetration of cold. In addition, you should pay attention to how even the coating turned out.
How to plaster the facade on foam plastic? To check this, you should apply the building level or rule. If there are irregularities, they must be eliminated.
The foam itself is a very smooth material and any mixtures or adhesives do not fit well on it. In order to increase the adhesive properties, special primers or a regular spiked roller can be used. The tool will make small holes in the base, and the applied solution will penetrate into them and be securely fixed.
If a primer is used, then before applying it, it is necessary to clean the base from dust and dirt that may settle during installation.
Do you need reinforcing mesh?
Even if the foam is prepared for applying the mortar with a primer, the plaster mixture is still not applied directly to it. In order to get a more reliable coating, a reinforcing fiberglass mesh is used.
It is optimal to choose a mesh with a density of 130/160 g/m2. Styrofoam plaster will fit well on such a reinforcing canvas, but it is difficult to work with it when finishing corners.
How to plaster
All work begins with cutting the grid for the corners. If slopes are processed, then the length of the mesh should correspond to the length of the slope, while the width is 30 cm. For the corners of the house, 1 meter will be measured.
This length is much easier to work with. The width is the same as for slopes.
Having prepared the solution according to the recipe indicated on the package, you can start plastering.
Do-it-yourself foam plastic plastering starts from the corner, and so let's get started:
- With a small spatula, apply the solution to a large spatula. Then apply the solution to the wall. The length of the strip must correspond to the length of the reinforcing mesh. How to plaster a wall on foam plastic video? The width at the same time on one wall will be equal to half the width of the grid plus 5-10 cm.
- The reinforcing mesh is bent in half in width and applied to the solution.
- We take a wide spatula and, smoothing the mesh, immerse it in the solution. The reinforcing element must completely penetrate the plaster solution. If the previously applied layer is not enough, then it is applied additionally on top of the mesh. The spatula must be moved from top to bottom and from the corner. This will create a more even surface.
- Further on the wall, applying another solution, which will be slightly larger in size than the next piece of mesh.
- Each subsequent segment of the reinforcing mesh is superimposed on the previous one by 5 cm.
- Everything is leveled and smoothed with a wide spatula. This is done throughout the area.
Stages of grouting and puttying
After finishing of the facade on the foam plastic is applied over the entire area, it must be left until completely dry. After waiting a certain time, how long the mixture will dry, usually manufacturers indicate on the packaging, you can start grouting.
This stage is necessary in order to obtain a sufficiently flat surface. For grouting, you can use sandpaper or special plastic floats. The device is moved counterclockwise.
Without missing a single section, minor flaws are removed.
Next, move on to putty. This procedure will make surface perfectly even and will hide the slight roughness that may remain after grouting. If the previous stage was done with high quality, then a finishing putty with a thickness of 2 mm will be enough.
After the putty has dried, it also needs to be rubbed. As a result of these actions, you will get a good, even surface that can already be painted. Painting of plaster is carried out with paint for concrete for outdoor use.
If you do not like this method of finishing the facade, you can choose decorative plaster.
Additional Information:
- moisture is not absorbed into the insulation boards, so all the water from the facade remains inside the finishing layer;
- the expansion coefficient of (temperature) foam plastic does not correspond to this indicator for plaster mixtures, therefore, due to temperature differences, the coating applied to the plates may crack and fall off;
- the surface of the insulation is smooth, dense, irregularities and micropores are almost absent, which makes it difficult for the solution to adhere to it.
If the material is too smooth, it is roughened
You need to start work with the design of corners, door and window openings. It is necessary to take a reinforcing mesh and cut off a fragment from it 30 cm wide and equal to the length of the slope, if we are talking about openings. For corners, the length should be 1 m. Then you need to bend the mesh so that its edges touch, and iron the bend. This is done so that the product retains its shape.
Using a spatula, glue or a universal mixture is applied to the foam, after which the reinforcing mesh is pressed against it. Is it possible to plaster on foam plastic with sand-cement mortar? For tighter contact between the product and the wall, iron the mesh with a spatula. It is important to ensure that the mesh does not deviate anywhere from the surface to be plastered and sinks into the solution to the same depth.
Then you can start pasting the main surfaces.
You can purchase ready-made mixes for foam plaster. The products of Ecomix and Ceresit companies have proven themselves well. At one site of construction work, it is recommended to use mixtures of one company.
The best option is to choose a universal solution (glue-plaster for foam), which is suitable for attaching the insulation to the wall and for arranging the protective layer.
Tile adhesive, preferably CERESIT CM-11, is mixed in a bucket and for this it is filled with water by 1/3, and then the powder is poured in (try not to fill the bucket to the very top - let at least 5-7 cm remain). For mixing, use a slow-speed drill with a putty mixer (not for paint) and beat for 5-7 minutes, and then let it stand for 5 minutes.
There are several steps to follow. But first you need to prepare the tools: a grater for plaster, a drill with a mixer, a paint grid, a building level, sandpaper for grouting, a spatula and a trowel. Of the consumables, you will need a plaster mixture, a primer, decorative plaster (mineral or acrylic).
Now you can transgress to the works themselves.
It would seem that it is quite easy to figure out how to plaster and wipe the foam plastic, and this operation can be done either with your own hands, or you can hire a construction team at a reasonable price. In both cases, do not make basic mistakes - buy only specialized mixtures for polystyrene foam, do not save on foam fasteners. If you are determined to do all the work yourself, watch the training videos.
In the process of facade insulation, expanded polystyrene is mounted on the outside of the building. Insulation boards are glued to the walls using an adhesive solution for PPS, and then fixed with dish-shaped (mushroom) dowels. To protect and preserve the properties, the surface of the heat-insulating layer must be closed from ultraviolet radiation, temperature changes and other atmospheric influences (wind, precipitation, etc.). One of the best ways to protect Styrofoam finishes is plastering .
This type of coating is stronger and more durable than others, moreover, it has a large selection of options. Plaster is perfect for both protection and decoration of the facade.
After the finish has hardened, the coating is polished. If there is no need for decorative processing, then the walls are lined with colorless varnish and the work with the foam can be considered finished. As a substitute for varnish, you can use paint for outdoor procedures.
Styrofoam is one of the most popular materials for thermal insulation of building facades. Foam insulation sheets have a large number of advantages, but they can be damaged due to exposure to the sun, temperature changes and high levels of humidity. Also, the appearance of such a material is not attractive, so often the foam is processed with a plaster mixture. This article will discuss how to plaster the foam outside and what tools will be needed for this.
Since external cladding is required, facade plaster on foam plastic must be frost-resistant and have protection from various atmospheric precipitation, so gypsum compositions will definitely not work. The best solution would be a cement-based plaster mortar, but not made independently from improvised materials. A special purchased composition is made with the addition of special elements that guarantee the strength and long service life of the resulting coating.
To plaster a foam facade, two types of compositions are needed. One will be used as an adhesive to perform the reinforcement procedure, the second - to level the facade walls. Universal solutions are also produced that combine both purposes.
If you plan to purchase adhesive and leveling mortar separately, it is best to purchase products from the same manufacturer. This will ensure their high-quality interaction. The consumption of adhesive is within 4 kg per 1 m², and plaster - 6 kg. The universal composition will require about 10 kg to process 1 m².
Styrofoam finishing process
The work on processing the facade surface consists of the following steps:
- Preparation of tools and mixing of plaster mortar.
- Reinforcing the surface with a mesh.
- Wall alignment.
- Facing with a decorative mixture.
The procedures must be performed in that order. They are not very complex, so even a novice in the construction craft can handle it and the involvement of specialists is not required.
Preparation of instruments and mixture
How can you plaster the foam outside? To process such a coating, you will need the following accessories:
- a container for the composition and a mixer for mixing;
- glue, knife and reinforcing mesh for processing the base;
- primer mixture and roller for processing;
- directly plaster composition and spatulas of different sizes;
- sandpaper or grinder for grouting.