The right choice of facade plaster can be a decisive factor affecting not only the appearance of the house, but also the aesthetic appeal of the entire site. At present, several main types of facade thin-layer plasters are presented on the modern building materials market. Depending on the binder used in the production, there are: silicone, acrylic, silicate and mineral plasters.
So, the composition of silicone plasters includes silicone resin; acrylic – acrylic resins; silicate – water-potassium glass with the addition of a plasticizer; mineral – high-quality cement with the addition of various polymers that improve adhesion and increase the elasticity of the plaster mass. The binder used in the composition of the plaster has a significant impact on the physical properties of the material, on the possibility of using it with various wall materials, since the plaster must have similar physical and technical characteristics with the treated base. So, for example, silicone, silicate and mineral plasters with high vapor permeability are excellent for plastering on natural materials or surfaces insulated with mineral wool; and acrylic, on the contrary, having a low degree of vapor permeability, are widely used in insulation systems using polystyrene foam boards.
It should be noted that neither the composition of the plaster, nor the type of binder used in its composition, nor its physical characteristics in any way affect the appearance of the plastered surface. By the appearance of the house, even a highly qualified specialist will not be able to distinguish the type of plaster used.
Therefore, the decisive factor in the choice of plaster should be its compatibility with the surface to be plastered and durability. Strange as it may seem, the durability of plaster is affected not only by its appearance and resistance to various atmospheric influences, but also by the type of texture and even its color. Resilience and durability. Resistance to atmospheric and mechanical influences, resistance to pollution have a great influence on the durability of the plaster layer. Despite the fact that there is a huge variety of plasters on sale, but not one of them has the same resistance to all of the listed harmful factors. Thus, acrylic plaster has high resistance to mechanical stress, silicate plaster is medium-resistant, and mineral plaster has the least resistance. The greatest resistance to moisture and precipitation is provided by silicone and acrylic plasters, and the least by mineral and silicate ones.
High resistance to direct sunlight is provided by mineral and silicone plasters, while acrylic ones are less resistant. The effect of low temperatures is best tolerated by mineral plasters, medium – silicate, and worst of all – silicate and acrylic. The superiority among plasters, in terms of resistance to pollution, remains with silicone, mineral and silicate have average indicators, and acrylic plaster occupies the last place. One of the decisive factors affecting the resistance of plaster to external contamination is the binders included in its composition. So, for example, if we consider acrylic plaster, then the resin included in its composition heats up in the sun, becomes viscous, begins to absorb and attract dirt, while firmly sticking to the material. For our climatic zone, one of the most important conditions for durability is the high resistance of the plaster layer to biological corrosion. This is achieved by including special biologically active preparations in the composition of the plaster, which resist the appearance and development of fungus and algae. If plaster compositions that do not have these properties are used for arranging the facade, then after several months of operation of the facade, a gray-green coating will appear on it, and the microorganisms present in it will cause destruction not only of the plaster, but also of the inner layers of the facade.
Texture and durability.
When choosing a plaster, it must also be remembered that various structural effects on the surface of the plaster also have a significant impact on its durability. A smoother and more even surface tolerates stresses worse, cracks and even chips are easier to form on it. While a rougher surface is less susceptible to this danger. Consequently, many experts do not recommend the use of facade plaster with a smooth surface. Currently, the most popular are two types of facade plaster textures: corrugated “bark beetle” and rough “lamb”.
The “bark beetle” plaster in its structure contains small pebbles, which, when grouting with a grater, when applying the plaster mass, carve vertical, horizontal or circular grooves on the surface, which visually resemble small channels left by insects in wood. The “lamb” plaster is applied using a trowel, roller or other tool (twisted rag or whisk), while providing a different arrangement of lumps on the surface, visually resembling lamb’s wool lumps.
Less popular is “scratched” facade plaster. Its composition contains fine gravel, which, during the grouting process, crumbles from the surface a homogeneous mosaic of densely packed grains of its deeper layers. In addition, the durability of the plaster layer is greatly influenced by its granularity. Modern manufacturers of plaster masses offer all types of plaster coatings with a grain size of 1 to 4 mm, and the larger the grain size of the plaster, the better, since when various stresses appear, it is more resistant to cracking. There is an erroneous opinion that the smoother the surface of the wall, the less dirt is collected and absorbed on it. However, this is not entirely true, since there may be less pollution on it, but they are much better visible. It should be noted that the direction of the grooves in the facade plaster layer does not affect the degree of its contamination.
Color and durability. It is not strange, but the durability of the color of the plaster layer depends on its saturation. Color fastness is directly proportional to the saturation of the plaster. This indicator is usually measured in degrees, so pure white means 100th degree, and saturated black (soot color) – 0th degree. The lighter you choose a shade for the facade (closer to the 100th degree), the more time it will have an attractive appearance, and vice versa – if a darker and more saturated color is chosen, the faster it will lose its aesthetic appearance. In addition, darker facades heat up more and, reaching high temperatures, additionally accelerate the burnout process. In addition, thermal stresses are created in them, the facade heats up and deforms, and as a result, the likelihood of deformation cracks on its surface increases. In addition, if you use a facade insulation system, then the temperature from the outer layer cannot be transferred deep into the wall, therefore, a strong overheating of the thin-layer plaster layer is possible. In this case, it is best to use colors of the facade above the 40th degree, and the use of colors of the 20th degree and below is highly undesirable. This limitation is absent in traditional plastering, but, nevertheless, this phenomenon should not be underestimated. When choosing the color of the plaster, it should be taken into account that the richest choice of shades has silicone and acrylic plasters (about 1.5 million), and the most modest (less than 100) – silicate and mineral plasters, which are mainly presented in neutral, not bright and not saturated colors.
In order for the facade to have an attractive appearance for a long time, it must be taken care of, it must be properly looked after.
There are several basic principles that must be strictly observed in order to extend the life of the plaster facade coating:
– avoid long-term pollution of the facade,
- prevent the formation of mold, fungus and other colonies of microorganisms on the surface,
- avoid major mechanical damage,
- periodically carry out routine repairs, timely eliminating minor defects,
- monitor the serviceability of the drainage system (downpipes and gutters), since water leaks along the facade can favorably influence the formation of fungus and mold.
In addition, there is another great way to increase the durability of plaster, increase its resistance to external negative factors, and also significantly extend its operation – to paint. So, it is recommended that a facade plastered with silicate or mineral plaster be painted once with paint of the same shade, which will allow it to retain its color for a longer time. In this case, it is necessary to choose the right type of paint for the plaster material, since otherwise you can only harm the facade.
Acrylic paint is suitable for mineral and acrylic plaster, silicate paint for mineral and silicate plaster, and any type of facade can be painted with silicone paint. During operation, the facades are not only possible, but also necessary to be washed. To clean the contaminated facade, depending on the degree of contamination, select your optimal cleaning method. So, for cleaning a not very dirty facade, a system of cold water of low pressure (up to 5 kg / cm2) is suitable. If it was not possible to get rid of pollution in this way, then you can try warm (about 40 – 500C) or even hot water (more than 500C), as well as special detergents and the use of brushes.
Please note that it is not recommended to clean the facade, which is plastered with mineral plaster, using brushes, as they can damage its surface. If the façade is heavily soiled, then it must be cleaned with high pressure water (100 – 120 kg/cm2). In this case, we recommend contacting specialized companies that have the appropriate equipment and experience. Particularly difficult pollution is removed with the help of water vapor, the action of which is similar to that of a detergent. After cleaning the facade, it must be rinsed with water. It is strictly forbidden to clean facades with a silicone or acrylic coating using water vapor, as the action of steam can damage the plaster (it may crumble). Currently, another method of cleaning facades has appeared – washing with dry ice. This type of cleaning is particularly effective and is suitable for any type of plaster, but in this case you will also have to contact a specialized company, since special equipment is used to carry out the cleaning. And lastly, do not allow significant damage to the facade, since it will not be possible to “imperceptibly” repair part of the facade, the repaired places will be more or less noticeable (depending on the qualifications of the performer). In this case, not the color (except for white), not the texture does not have any effect on the quality of repair and restoration work.
We hope that our advice on the right choice of facade plaster (its colors, textures) and recommendations for caring for the facade will allow you not only to become the owner of a beautiful and aesthetically attractive home, but also to avoid most common mistakes in its operation.