What are the features of facade insulation with plaster mixtures, what are the pros and cons of this method, how to prepare the solution yourself, the technology of its application to the wall. Insulation of the facade with plaster is a budgetary and popular method of thermal insulation of walls using a special cement mortar. It contains not ordinary sand, but perlite or expanded clay crumbs, as well as sawdust, pumice powder, paper and other materials. This method of insulation is also called "wet facade".
Features of work on the insulation of facades with warm plaster
Recently, the so-called "warm plaster" has become widespread among thermal insulation materials. At the heart of this mixture is a cement mortar to which a filler is added. The latter must have the following main qualities:
- Hydrophobicity … Helps prevent moisture from entering the façade.
- Vapor permeability … Water vapor must pass through the material and not condense.
- Low thermal conductivity … This quality helps the material to keep warm.
All these qualities are fully possessed by porous materials, which enable the plaster to breathe and not let cold air and moisture pass through. Therefore, vermiculite (light mineral substance), expanded polystyrene, pumice powder, expanded clay chips, sawdust, paper can act as fillers. For insulation of facades, plaster is mainly used with the addition of pumice, expanded clay and expanded polystyrene. The mixture with the rest of the fillers is used mainly for interior decoration. Warm plaster has earned its popularity due to its unique feature. Using just one material within the framework of one technological process, you can get a good insulation of the facade, noise and waterproofing, an aesthetic exterior finish.
As a heat-insulating material, warm plaster can be used for finishing even those facades that are decorated with decorative details. In addition, it is used to insulate window slopes and door blocks, internal and external walls, water supply risers, sewers, floors, ceilings and others.
Advantages and disadvantages of facade insulation with plaster
The method of insulating facades by means of plaster is quite simple, budgetary and does not require labor-intensive work.
Let's consider the main advantages of this method:
- Simple application process. Excellent adhesion of warm plaster is manifested in the fact that it "sticks" to almost all types of surfaces. The material will not fall off or crack if all installation work is carried out in accordance with the rules.
- No complicated preparatory work needed. You do not have to remove irregularities from the walls in advance, since the material used in the insulation process is quite plastic and can itself act as a leveling agent.
- High speed of plastering. The technology of insulation with plaster is not much different from the usual plastering of walls. You can apply the material manually, or you can use a special technique to automate the process.
- The method is suitable for finishing complex carved facades. It is quite possible to emphasize the main decorative elements on the surface with plaster. At the same time, unnecessary irregularities, defects, cracks, chips can be easily eliminated.
- Lack of cold bridges. Since the heat-insulating material will not have joints, there cannot be cracks through which cold or moisture can penetrate either.
In addition, this material is environmentally friendly under any temperature conditions. It will not burn, smolder, decompose, freeze, since it consists of natural non-toxic components. Rodents or microorganisms will not start in the plaster.
Using plaster for insulation, you also solve the issue of sound insulation and decorative finishing of the facade. This method of facade insulation can be used even in hospitals and public institutions for children. Among the disadvantages of this method of thermal insulation, it is worth highlighting the following:
- The facade insulated with plaster will have to be additionally covered with a primer, paint, since this heat-insulating material cannot act as a finishing material.
- It is necessary to apply "warm plaster" only on a dry surface, since it cannot be a sanitizing material.
- The coefficient of thermal conductivity of plaster is several times higher than that of many other heaters. It averages 0.6-0.8 W / (m ° C). Thus, the plaster is approximately two times colder than the extruded polystyrene foam. Therefore, for high-quality insulation, its layer should be one and a half to two times thicker than when using other materials.
- To carry out the insulation of the house from the outside with plaster, a stable foundation of the building is required. The material has a very high density, which exceeds the same indicator of mineral wool or expanded polystyrene 10 times. Not every foundation is capable of supporting this additional weight.
- In order to better retain heat, it is recommended to apply insulation outside and inside the house, since the layer should not exceed 50 millimeters, and this, as a rule, is not enough in a harsh winter for high-quality thermal insulation. If the plaster is laid in a thick layer, then it will slide or fall off the wall under its own weight.
The technical characteristics of the material for the insulation of facades may differ depending on the filler and the brand. So, some plasters do not need painting or other finishing, however, their price will be much higher than that of ordinary ones.
How to make warm plaster with your own hands
Facade insulation plaster is a material that you can easily prepare yourself using inexpensive components sold in any hardware store.
There are several recipes for making plaster for wall insulation, which differ in composition and proportions:
- Plaster based on natural materials … This solution is suitable for insulating facades in areas with a fairly warm climate. To prepare it, you will need the following components: cement (0, 2 parts), clay (1 part), paper pulp (2 parts), sawdust (3 parts). So much water is required so that the finished mixture is similar in consistency to a paste and it is convenient to apply it to the wall with a spatula.
- Plaster with perlite or vermiculite … Add the following ingredients in sequence to the container: cement M400 (1 part), vermiculite or perlite sand (4 parts), plasticizer. The latter can be PVA glue at the rate of 50 grams per bucket of cement. Add water by eye so that the mixture is pasty.
- Plaster with perlite and expanded polystyrene … Insulation of the facade with heat-insulating plaster prepared according to this recipe is considered the most suitable for cold winters. Prepare and mix the following components: cement (1 part), perlite sand (3 parts), ready-made plasticizer in the amount indicated on the package, expanded polystyrene with a fraction size of 1-3 millimeters (1 part), polypropylene fiber (50 grams). Add water to obtain a thick consistency and mix thoroughly with a construction mixer.
You can check that the mixture is being prepared correctly by applying a small amount to the trowel and turning it over. If the composition has not fallen off, then it is ready to use. The same method of checking the readiness of the plaster can be used for purchased mixes from manufacturers.
Facade insulation technology with plaster
Applying warm plaster to the wall is no more difficult than conventional plaster. There is no fundamental difference between these two processes. The main thing is to maintain the thickness of the layer of mortar applied to the wall in order to ensure the optimal level of thermal insulation.
Calculation of material for facade insulation
To get a decent level of thermal insulation on "cold" walls made of brick, reinforced concrete in northern latitudes, you need a layer of plaster, which will be equivalent to at least 10 centimeters of polystyrene foam. This means that its thickness should be about 20 centimeters or more.
In practice, however, such a layer cannot be applied. Its maximum thickness should be 5 centimeters on each side of the wall. Therefore, a standard layer will only help to slightly additionally insulate the building. We are not talking about creating a so-called full-fledged "warm house" using only warm plaster. Material consumption is significant and amounts to:
- For a layer of 2 centimeters - from 8 to 12 kilograms of solution per square meter;
- For a layer of 3 centimeters - 12-16 kilograms of the mixture per square meter;
- For a layer of 4 centimeters - 16-24 kilograms of plaster per square meter;
- For a layer of 5 centimeters - from 18 to 25 kilograms per square.
Preparation before insulating the facade with plaster
The surface of the facade is prepared for plastering in the same way as an ordinary plastering wall. First of all, it is necessary to remove dust, dirt, remnants of old solutions. If cracks, potholes, and other defects are found on the wall, it is recommended to strengthen it with a plaster mesh.
It will not be superfluous to install a plaster grid on monolithic smooth walls made of concrete or sand-lime bricks. It is attached to a row of dowel-nails. If the facade of the house is affected by mold, fungus, then the surface must be treated with a penetrating antiseptic primer or special impregnation. Before starting the process of insulating the facade with "wet plaster", prepare the necessary tools: a trowel, a building level, as a rule, several spatulas, beacons. The latter can be in the form of thin strips of metal or plastic.
Instructions for applying plaster to the facade
You need to prepare a mixture for insulating the facade in such an amount that you can use it within two hours. The prepared solution must be left to infuse for 5 minutes.
In order for the insulation with warm plasters to be as effective as possible, it is recommended to carry out work on applying the mixtures at a temperature of at least 5 degrees Celsius, and an air humidity of about 70%. We carry out the work in the following order:
- We fix the beacons on the wall on the solution. We verify their position using a stretched cord or a building level. They should be located in the plane of the future surface formed by the plaster layer.
- Apply the first layer with a trowel, spray or brush. Its thickness should be 2 centimeters. We work from the bottom up.
- We level the mixture with the rule, relying on the beacons.
- Leave the first layer to dry well for four hours.
- Apply a second layer of the required thickness. Usually it is no more than three centimeters. We level the plaster with the rule and rub in with a float.
- After the second layer has dried, the surface should be re-cleaned and leveled with a float. It takes 4-5 hours to completely dry the plaster.
Note! If you plan to apply the composition using a spray or spray with a brush, then its consistency should be more fluid than using a trowel and spatula.
Finishing works
The facade, insulated with plaster, needs finishing. It can be carried out both immediately after the heat-insulating mortar has dried, and after some time.
The main thing is to adhere to these recommendations:
- Before covering the surface with decorative materials, check its evenness again using a building level. The maximum deviation in different areas can be no more than 3 millimeters per square meter.
- It is best to start painting no earlier than three days later.
- It is recommended to use paints that do not form a film on the surface to allow the walls to breathe.
The maximum strength of the plaster layer is achieved only 28 days after application. And the thermal insulation properties reach a maximum 60 days after the final drying of the mixture. How to insulate a facade with plaster - watch the video:
Warming a house with plaster is a convenient, fast and inexpensive way of thermal insulation. You can not only carry out your own work on applying the composition to the facade, but also prepare it at home. However, it should be remembered that, despite the many advantages, this method is not suitable in all cases. In particular, "warm plasters" are not effective enough in severe frost conditions.
