Facade plaster: types and characteristics

One of the simplest and lasting ways to give building facades an attractive appearance is to use outdoor plaster. With the help of this material, it is possible not only to provide the structure with aesthetic appeal, but also to protect it from the adverse effects of the external environment.

Plaster in translation from Italian means "lime, gypsum, alabaster". It was these materials that formed the basis of the first such solutions. Today, the material is a synthetic mixture, which, depending on the type, contains cement, sand, silicone, acrylic, etc.

Facade plaster is intended for outdoor use and must meet the following requirements:

• good indicators of vapor permeability (otherwise, the greenhouse effect between the layer of material and the walls of the building cannot be avoided, which means the destruction of the latter, the appearance of mold spots outside and inside the building);
• resistance to negative natural factors, temperature changes;
• resistance to mechanical and static stress;
• ease of application.

The mixture can have a different composition, which greatly affects its technical characteristics, in particular, the durability of the coating. On average, repairs will be required in 7-10 years for cheaper mix options and in 15-20 years for premium materials.

The material has such advantages as environmental friendliness, fire safety, the ability to obtain a variety of aesthetic effects, light weight, moisture resistance and vapor permeability. However, if we compare its strength with the strength of ceramic or facing tiles and a number of other materials for home decoration, then plaster is significantly inferior to them. That is why plaster is actively used to decorate a private house and, a little less often, public institutions.

Facade plaster is intended for finishing walls.

The composition is used when performing the following types of work:

• serves to level surfaces, eliminate joints, cracks, gaps;
• allows you to create a homogeneous seamless coating;
• the heat-insulating function allows you to reduce the number of heaters used, eliminate "cold bridges" and increase the thermal efficiency of the building;

• protection of combustible materials from fire;
• protection against radiation, atmospheric exposure;
• giving the building aesthetic appeal and uniqueness.

Depending on the composition and the presence of additional properties, the following types of plaster for facades are distinguished:

It is considered the most common (it is more often used gypsum), it contains cement, sand of a suitable fraction, lime. Cement mixtures can be applied to working bases made of concrete, aerated concrete, brick.

The demand for cement plaster is due to good adhesion rates - it does not require additional compounds to improve adhesion to the surface. The applied solution holds well without chips for a long time.

The leader among finishing materials, cement-based plaster is made by its increased strength and the possibility of using it even in humid climatic conditions. For the mortar, cement of increased brand strength (M400) is used, and its proportion with sand is 1: 3 (compare - for interior work it is 1: 4).

If we talk about the "disadvantages" of the coating, then it is worth noting a rather long time of solidification of the composition (in addition, a preliminary long-term preparation of working surfaces will be required) and its considerable weight, which entails a load on the building frame.

Cement plaster is suitable if its priority is the durability and availability of the coating without perfect smoothness. The hardened surface can be painted with acrylic paints.

Its base is "liquid glass", that is, a solution of potassium and sodium alloys, due to which the characteristics of high vapor permeability and fire safety are achieved. The latter, by the way, allows you to apply plaster on surfaces insulated with expanded polystyrene.

In addition, surfaces covered with silicate plaster do not attract dust. (due to the neutral electrostaticity of the material), resistant to environmental influences.

Thanks to the variety of textures and colors, it is possible to implement various design projects, to achieve the uniqueness of the structure.

After drying, the composition does not deform, however, the process of its application is quite laborious, and, as a rule, requires the involvement of professionals. The surfaces are pre-primed. The material can be applied to concrete and plasterboard surfaces. But on polymer insulation, varnished and oil-painted surfaces, the silicate-based composition does not fit.

Acrylic-based decorative plaster is characterized by a large selection of textures and colors. In addition, it has elasticity and resistance to the external environment and moisture. This is the merit of the modifiers and plasticizers present in the composition. Due to the increased elasticity of the material, it is well suited for filling cracks, tightening gaps on the wall. Bactericidal components are also mandatory in the composition, which provide protection of the layer from the appearance of mold and fungi.

Like other types, the acrylic composition is characterized by vapor permeability. In addition, its use allows achieving good sound and heat insulation results. It is quite durable, its service life is 15-20 years. The average cost of acrylic plaster is 1,700-3,000 rubles for a 25 kg bucket of mix. It should be understood that the costs will also be associated with the involvement of professional staff to apply the composition. Preparatory work requires special skills, and the plaster itself quickly hardens - it must be applied as quickly as possible.

Among the disadvantages of the coating is its high electrostaticity, and therefore the surface is quickly contaminated. However, it will not be difficult to clean it by watering it with a hose. Unfortunately, the composition does not have the highest UV resistance characteristics.

The solution is based on silicone (more precisely, silicone resins), so this plaster is more elastic than acrylic. Thanks to this, it is possible to obtain perfectly smooth surfaces. Manufacturers also delight in a variety of color options - there are more than 200 of them.

Among the main advantages of the material is its hydrophobicity (that is, avoiding contact with water, repelling the coating of the molecules of the latter). The plaster is characterized by vapor permeability, good adhesion, vibration resistance.

It does not require special care and is quite unpretentious in operation. However, the application of the silicone solution should be handled by a professional, since specific preparatory work is required, in particular, the application of a silicone-based primer. When applying, both manual and spray techniques can be used.

It should be remembered that the composition is not suitable for application to external insulation. To solve this problem, a decorative plaster layer is laid over the base and reinforcing mesh.

It is worth noting the high cost of the material - you will have to pay from 2,500 to 5,000 rubles for a 25 liter bucket.

Its basis is cement and slaked lime, as well as fine-grained filler (colored clay, stone chips). To create a mineral plaster mortar, cement with a strength of M500 and higher is used. This provides increased strength of the material, resistance to temperature extremes (the permissible frost index is up to -50C), and the duration of operation (on average 15 years). Plaster is characterized by non-combustibility, good heat and sound insulation properties.

The presence of filler in it allows you to achieve certain stylistic effects of the coating. However, the color variety is out of the question. It is possible to give a shade to the mineral mixture only after its application and hardening (after 2 days) by staining with special paints.

It is a kind of decorative facade plaster based on cement, sand, lime component with the addition of marble chips and mica. This provides an interesting visual effect and guarantees surface durability.

Among the main advantages of the coating is its resistance to environmental influences, versatility of use (also suitable for interior decoration), long service life. It is worth noting the laboriousness of the application process and the long time of setting and drying of the material.

Decorative plaster of this type is becoming more and more popular among connoisseurs of eco-style. Due to the presence in the composition of natural oak bark, which is "immersed" in modifiers and binders, the material has the characteristics of natural cork. First of all, it is a unique appearance, as well as softness, anti-static, elasticity, environmental friendliness. Suitable for application on aerated concrete, expanded clay block, wood, plastic plastered and unplastered surfaces.

If we talk about the functional characteristics of solutions, then plaster can be of the following types:

Suitable for those buildings where the existing insulation does not cope with its functions, and the building frame will not withstand its additional layers.

"Warm" plaster contains sawdust, expanded polystyrene, verkulite, perlite or foam glass. Vermiculite and similar perlite plasters are very heat efficient - 3 cm thick of such plaster will replace a 15 cm layer of brickwork.

Such plaster is used as an auxiliary material in combination with mineral wool, foam plates.Together they significantly reduce noise levels and are used for buildings located near highways, industrial facilities, airports and railway stations, tracks.

For the plaster to absorb sound, it must be cement-based., additionally contain pumice, shpak, magnesite. This gives the surface porosity, which is the key to sound absorption.

The structure of the plaster affects the durability of the surface. So, smooth plaster is more prone to cracking than structural. Rough surfaces such as "lamb" or "grooved bark beetle" are more resistant to environmental stress and cracking.

The textured surface is achieved due to the presence of fillers in the composition or the use of special tools. For example, a "lamb" implies the use of special rollers and half-beads, with the help of which lumps are formed at regular intervals. The "bark beetle" contains small pebbles that form grooves when grouting.

Among the popular textures:

• "Kameshkovaya" is a composition with small inclusions. Their diameter is 1-3 mm. The roughening effect is achieved by rubbing with a plastic float or using a trowel, brushes.
• "Bark beetle" is a texture with numerous grooves - horizontal, vertical, wavy. The texture is created using the same materials as the "pebble" one.
• Mosaic, which is based on a silicate or silicone mixture. Stone chips of a large fraction of various shades are added to it. As a result, the solidified surface resembles expensive rocks, and the multi-colored granules create a bizarre pattern.
• "Lamb" is a soft hillock layer, which is achieved due to stone grains of various fractions in the composition. A kind of "pebble" texture.

Venetian plaster, surfaces imitating shagreen, natural finishing materials (granite, marble) are very popular.

Colored plaster can be obtained in 2 ways: due to the presence of pigment in the solution and by coloring the plastered surfaces. In the first case, the surfaces have beautiful, multifaceted and rich shades, characterized by long-term durability.

The application of the composition is different for each type.

However, there are still universal rules:

• First of all, preparatory work is carried out - the surface is cleaned and leveled, if necessary, primers are applied. The task of the latter is to improve the adhesion of working bases and plaster. Beacons are used to level surfaces.
• When using some mixtures, for example, textured plaster with the "bark beetle" effect, preliminary insulation of the walls is carried out.
• Since the plaster slides downwards, it must be applied from the bottom up.
• The last stage is the creation of texture, the formation of protrusions, etc.

When plastering on top of the heat-insulating material, a mesh for reinforcement is preliminarily glued to the latter. It must be overwritten without fail. This can only be done if the mesh glue is completely dry.

The next step is to apply a leveling compound., which will become the base for the next layer. After it dries, wipe the layer. Then you can start plastering, applying a primer if necessary.

When applying plaster to brickwork, the latter is subject to priming and installation of beacons. After that, plaster is sprayed onto the pre-moistened surface, which is then leveled with a spatula from bottom to top.

Having plastered the volumetric area, the resulting layer is leveled with the rule, and then the grooves are scratched. They will help to increase adhesion followed by a layer of plaster. As the first layer dries up, the finishing method is performed.

The silicate mixture is sprayed onto the surface. At the same time, you cannot use it on recently constructed buildings, since during the process of their shrinkage, the surface will crack. Application thickness - no more than 20 mm. Grouting is carried out 48 hours after application with a float.

The peculiarity of acrylic plaster is a high degree of adhesion, so it must be applied quickly. This is usually done with a spatula, sometimes a spray bottle is used. Remember that when dry, the color of the surface is darker than the shade of the liquid mixture.

When filling, it is recommended to work not by square meters, but by areas. If the presence of connecting seams and corners is expected, masking tape is pre-applied to them. This will allow you to achieve evenness and invisibility of the transitions.

The so-called "wet" method of plastering has become widespread. The value of this method is to obtain an optimal microclimate in the building, since the dew collection point is removed outside the structure. This method involves attaching insulation, mesh for reinforcement and plaster to external walls using liquid and semi-liquid adhesives.

Such a facade is a multi-layer "sandwich", the components of which are heat-insulating, base and decorative layers. Insulation (as a rule, it is a mineral wool version, expanded polystyrene or OSB boards), is attached to the base with cement compounds.

When choosing a plaster, one should take into account the climatic conditions of the building and its purpose, the type of working base.

To provide additional heat to the building, pay attention to compositions containing foam glass, perlite, vermiculite. In regions with high humidity, the moisture-resistant performance of the plaster should be maximized. The so-called "winter" or frost-resistant version is optimal for northern regions. For those who wish to repair the facade as rarely as possible, acrylic (service life - up to 25 years) silicone and silicate (serve 15-20 years) compounds are suitable. Cement compositions are distinguished by the least durability, their service life is 10 years.

Long-term preservation of functionality and aesthetic appeal is associated with the texture of the plaster. Smooth and smooth surfaces are more susceptible to cracking, while rough ones are not only more resistant, but also hide minor surface imperfections. When buying plaster, it is important to understand how it matches the type of walls. Otherwise, even an expensive and high-quality composition will not fulfill its functions. So, for brick, it is better to use cement or silicone compounds, and for aerated concrete - silicate or silicone. For framing, choose an elastic acrylic blend. The tree will accept silicate plaster well, and it is recommended to apply acrylic plaster on top of the reinforcing mesh on the insulation plates.

In addition, when plastering a wooden building, you will need to take care of the presence of a special mesh with large cells or a shingle frame. Cement mortars are universal - suitable for all types of walls, including cold and damp basements. If laying is meant on the surface of the insulation, a reinforcing mesh is pre-laid.

All plasters are divided into 2 types:

• thick-layer - silicate and cement mortars;
• thin-layer - these include acrylic and silicone containing mixtures.

The use of the latter type of solutions involves careful preparation of working bases - cleaning, leveling.

The ready-made mixture is more convenient to transport and use (there is no need to calculate the ratio of parts of the composition and water, to knead the solution), but it costs more than dry mixtures. In addition, this shape is not possible for all types of plaster.

Plastering can be an expensive pleasure, so always consider the material consumption per square meter. m. This will help not only get an idea of ​​the total cost of the mixture, but also correctly calculate the required volume.

In general, consumption depends on factors such as the type of filler and binder, and the type and evenness of the working substrate.

On average, for different types of plaster, the consumption is as follows:

• acrylic-based formulations - 1.5-3 kg / m2;
• silicone compounds - 2.5-3.9 kg / m2;
• mineral plasters - 2.5-4 kg / m2.

Having calculated the volume of material required for work, add another 5% to it. These are the so-called work losses. In the absence of such an increase, you run the risk of finding yourself in a situation where the mixture was not enough and you have to buy it in addition, choosing the desired shade. In this case, construction will be suspended.

When choosing a material, not only its functional, but also aesthetic characteristics are important. It is logical that users want the color to last as long as possible.

The durability of a color coating is due to several factors:

• paint is applied over the plaster or color pigments are dissolved in the composition (the second option is preferable);
• antistatic indicators of plaster, on which the degree of surface contamination depends;
• resistance of the color pigment to precipitation and UV rays.

The best result, based on the above parameters, is demonstrated by silicone plaster. It does not attract dust, does not fade and, moreover, is characterized by a rich color palette. Slightly inferior to her is silicate plaster, which cannot boast of such a variety of shades. Acrylic solution is prone to fading, in addition, it quickly becomes dirty. Mineral and cementitious coatings, which require almost annual painting, show the worst color durability indicators.

Among the popular manufacturers of plaster mixes today, one can note the German Ceresit brand... The additives used in the composition provide elasticity (does not deform when the building shrinks, fills and hides cracks on the surface), vapor permeability (makes walls "breathable") and durability (surface service life - up to 20 years).

The range of the company includes 3 types of solutions for outdoor use:

• polymer mixtures based on cement, characterized by affordability;
• mixtures based on polymer properties with more impressive technical characteristics;
• polymer-cement plasters, which, in addition to cement and sand, contain synthetic additives of polymer origin, plasticizers. Such compositions are of high cost.

Compositions based on polymers can be acrylic (recommended in areas with high rainfall and humidity), silicone (also suitable for areas with aggressive environmental influences) and silicate (with increased resistance to deformation and UV exposure).

Knauf plaster is characterized by high quality and an extensive product line:

• Knauf "Unterputz" has a sand-cement composition and is used to eliminate technical joints, fill joints. It is also used on surfaces exposed to high humidity.
• Knauf "Grunband" is a versatile plaster with thermal insulation properties.
• Knauf "Diamant" is mineral-based and is considered one of the best decorative coatings. Combines aesthetic appeal and resistance to environmental influences, mechanical damage.

• Knauf "Sockelputz" is specially designed for application in the area of ​​the building plinth and is characterized by increased strength.
• Knauf universal fully lives up to its name and is suitable for plastering most surfaces, acting as a base layer.
• Knauf "Start 339" is a kind of primer. This type of plaster is applied on non-absorbent types of surfaces and serves as a preparation for subsequent types of mixtures.

• Knauf MP 75 is designed for machine application, optimal for plastering large surfaces.
• Knauf "Adgesiv" is a plaster designed for spraying base layers in order to increase their adhesion characteristics and achieve hygroscopicity.
• Knauf "Sevener" is another multifunctional compound. It is used as an adhesive for fixing insulation to walls, a mixture for repairing previously plastered surfaces and is used for leveling bases.

Plaster "Prospectors" - a product from domestic manufacturers, made according to a European recipe. Experts note hygroscopicity, improved adhesion rates and optimal solution viscosity. The advantage is the availability of both dry and ready-mix mixtures in the assortment.

Outdoor plaster is available in several variations:

• Facade based on cement.
• Finishing, used for outdoor and indoor work. The purpose of its application is to complete the finish, give it the desired texture, or, conversely, smoothness.
• Fcrylic, characterized by a high coefficient of plasticity and containing antiseptic additives. The latter make it suitable for application to damp, mildew and mildew-prone surfaces.

In this video you will learn more about Terracoat façade plaster.