Lightweight, practical, reliable, inexpensive cellular concrete has created competition for traditional building materials. But at the same time we have to look for new finishing technologies, and special attention This requires plastering of aerated concrete walls indoors and outdoors. Many factors have to be taken into account: the unpresentable appearance of aerated concrete, the non-moisture resistance of foam blocks, shrinkage, and poor adhesion, so special requirements are put forward for plaster.
Next, we will analyze in detail how the technology of plastering walls made of aerated concrete and other cellular surfaces differs from finishing high-density materials, we will provide step-by-step instructions, we will tell you what types of mixtures for blocks exist, and how to prepare the solution yourself. We have also selected several videos on how to plaster walls made of aerated concrete with your own hands; video tips will help you avoid basic mistakes when performing work.
Types of plasters for concrete, aerated concrete, foam blocks, expanded clay concrete, gas silicate blocks
Plaster is the most rational way to protect, level and finish surfaces made of foam concrete and aerated blocks; only it will help to properly optimize operational properties porous material:
- improve heat and sound insulation;
- protect from harmful chemical, biological and atmospheric influences;
- prevent the saturation of foam and aerated concrete with dust and hydrocarbon compounds, thereby preventing shrinkage and cracking;
- provide good vapor barrier, oxygen exchange is a good preventive measure against the formation of fungi and mold;
- improve hygroscopic characteristics;
- protect from large temperature deltas;
- prevent wear and mechanical damage to concrete blocks.
Watch how internal aerated concrete plaster is done, a video about preparing the base.
Block to block - discord
At the moment, there are two types of cellular concrete blocks, they differ in manufacturing technology:
- Cast foam concrete blocks - the solution is poured into a special molding cassette template, where it hardens until completely cured. This method of production has significant disadvantages: when hardening in the open air, irregularities and bumps are formed, and when their forms are pulled out, chips of edges and corners are common. To facilitate removal, the formwork is impregnated with special oil compositions, which eat into foam concrete and do not contribute to the adhesive characteristics of plastering.
- Sawn foam blocks have good geometry, as they are made in a large solid slab, which, after hardening, is sawed into segments. The edges are smooth, the surface is rough. Walls made from such blocks are much easier to plaster. Aerated concrete blocks are also made by sawing, but during the production process they are subjected to vibration in order to compact the material, speed up reactions inside the solution and hardening. After the unevenness and bubbles are carefully cut off from the surface with a string and concrete block placed in an autoclave for heat treatment. Plastering on aerated concrete for interior work and exterior finishing is much simpler compared to other blocks made of cellular concrete.
To improve the physical and mechanical characteristics of the blocks, polystyrene foam is added to the working solution; the output is an improved polystyrene foam block
Good to know: IN foam concrete blocks air bubbles are closed, isolated (each separately), in aerated concrete products they are open, which worsens resistance to heat transfer, reduces moisture resistance and frost resistance.Properties of plaster for foam and gas blocks
Plaster for external and internal finishing of gas and foam concrete blocks should not interfere natural characteristics porous material. And above all, vapor permeability should be taken into account. If this property is omitted, condensation will accumulate between the wall and the plaster, and as a result, fungus and mold will develop. Therefore, plaster for gas and foam blocks should conduct well air currents and water vapor. And of course, the plaster must have high adhesion, otherwise it will simply peel off even from a well-prepared gas or foam concrete surface.
Important: Interior finishing in houses made of gas and foam concrete should be carried out first, and only the next season can you begin facade work. It is advisable to begin all work only six months after completion of construction; this period is enough for the structure to shrink and the blocks to dry.Plastering walls made of gas silicate blocks and foam concrete must fulfill two mutually exclusive requirements: to be sufficiently vapor-tight to maintain the microclimate in the room comfortable for life, and at the same time, to conduct air and moisture pores well to protect the walls from microorganisms and fungal attack. In addition, if condensation accumulates between the layer of plaster and the wall made of foam or aerated concrete, then after several cycles of freezing and thawing load-bearing structure will begin to collapse.
Types of cellular concrete used in modern construction
Which plaster for foam and aerated concrete blocks is better to choose?
According to experts, for plastering walls made of foam and aerated concrete blocks, it is better to use ready-made dry mixtures, sold in 25-30 kg bags. They contain additives and plasticizers that improve the physicochemical characteristics of the solution, adhesive and vapor-permeable properties.
Table of plaster mixtures for walls made of cellular concrete
Watch the lesson on how to do thin plaster on walls made of foam blocks with your own hands; the video will help you understand all the technological nuances of the process.
Special plaster for gas silicate blocks and foam concrete, developed by manufacturers taking into account all the characteristics of the material:
- Sh-36 is a cement-based dry mixture containing synthetic reinforcing fiber.
- PROFIT CONTACT MN - cement-sand mortar with special additives, plaster for mechanized application.
- Dali - universal plaster for foam and gas concrete walls.
- MIX mask is a dry cement-quartzite plaster, improved with polymer additives.
- ATLAS KB-TYNK is a lightweight wall mixture for cellular concrete.
Technology of plastering walls made of cellular concrete
The difference in the characteristics of gas and foam concrete blocks also suggests differences in the technology of plastering walls. One general rule is that preference should be given to ready-made thin-layer, lightweight plaster mixtures.
Preparation
To façade and interior plaster walls made of aerated concrete and slabs adhered well and did not peel off; the surfaces must be thoroughly cleaned of grease and bitumen stains. Casting blocks should be treated with a coarse abrasive, while sawing blocks are rougher, so here you can get by with sanding only on slopes and corners.
The next step is primer:
- It is better to impregnate aerated silicate walls with compounds with water-repellent additives, a primer for aerated concrete for plaster on an organosilicon base and alcohols as solvents;
- It is recommended to impregnate foam concrete with emulsions from a mixture of polymers, deep penetration, which reduce the absorption characteristics of surfaces.
The soil must contain additives that prevent the formation and development of fungi and mold.
The mesh can be reinforced with a quick-drying solution or with a mushroom duble
After treating the walls, we strengthen the reinforcing frame, it is rational to use polymer meshes that are resistant to an alkaline environment, the cell size depends on the thickness of the solution layer. We set up the beacons and reinforce the corners with a special profile.
Note: If the plaster layer is up to 15 mm, then it can be applied in one step, but if it is thicker, then the process should be divided into 2 or more stages, 1 layer of mortar with a thickness of no more than 10 mm should be applied at the same time, subsequent ones - 20 mm each.
Spraying will increase the adhesive properties of walls
Facade plaster for foam blocks
The optimal external plaster layer for foam concrete is 15-20 mm. We moisten the walls well with water from a spray bottle. We dilute the mixture as indicated in the instructions on the package. For the first layer you will need a solution with the consistency of liquid sour cream. We spray it, a layer of 5-10 mm, let it sit for a while, this will provide better adhesion.
The second layer is applied with a thick solution; it should not flow off the trowel. We add the required thickness and draw out the solution using the rule. After 20-30 minutes, smooth out small irregularities with a spatula.
Plaster for foam blocks inside
For better adhesion, the inside of the foam block walls should be treated with an additional layer of soil. Remember that the inner plaster layer must be 2 times thicker than the outer one; this is the only way to bypass the dew point at the plaster/block interface.
Apply a base layer of mortar from bottom to top and straighten it using the beacon rule. We apply a thinner finishing layer when the main one has dried. It should not be thicker than 10 mm; the surface is leveled with a grater, in a circular motion, with force.
Facade plaster for aerated concrete
Vapor-permeable plaster for aerated concrete, a special ready-made mixture with a high content of gypsum, which also contains fine-grained perlite sand and lime paste, are suitable here. The mixtures are universal, suitable for external and internal use.
Remember, it is not recommended to make the outer plaster layer more than 20 mm. To decorate the walls with your own hands, add a layer of mortar and level it using the beacon rule. When the solution sets, apply thin layer up to 5 mm, and carefully smooth the surface for painting.
Plaster on aerated concrete for exterior use must be protected from getting wet; this is especially important in regions with a humid microclimate. To extend the service life of the finish and the house as a whole, external plaster for aerated concrete walls is treated with a protective layer of water repellent.
Plastering aerated concrete walls indoors
Internal plastering of aerated concrete is performed with non-moisture resistant mixtures. In bathhouses, bathrooms, swimming pools, the surfaces are treated with waterproofing materials, and only then the walls are plastered with moisture-resistant cement-based compounds.
Rough finishing - apply the mixture to the prepared wall, leave for an hour, carefully smooth. Next you can proceed to finishing, on a properly prepared base layer you can safely apply decorative plaster, stick tiles, putty for wallpapering.
Recipe for homemade plaster mixture for aerated concrete
For large volumes of work, buying a ready-made mixture can be expensive; a solution made by yourself will cost much less. We offer a recipe for plaster for aerated concrete walls:
- 1 part of cement, not lower than M400;
- 3 parts of milled sandstone, fraction up to 3 mm (some masters recommend using perlite sand);
- 1/3 lime dough.
Mix the dry ingredients thoroughly, add water and lime, bring the solution to a paste. Liquid soap can be added to the solution as a plasticizer.
We invite you to watch the final stage of plastering concrete walls with your own hands; the video demonstrates the pre-finishing process.
The article popularly talks about widely used building materials, lightweight concrete, main characteristics and finishing methods using traditional technologies, plastering house elements.
Plastering aerated concrete walls
Plastering interior and exterior structures made of lightweight concrete is the most commonly used method of protecting against the effects of external climatic conditions and giving the house an original, respectable appearance, as well as internal comfort.
The prevalence of the technology is due to the ability to inexpensively and independently carry out a set of works on the preparation and finishing of structures and achieve the desired results.
Special characteristics of aerated concrete blocks
Aerated concrete refers to cellular concrete and consists of quicklime, cement, sand and gas-forming aluminum powder. When mixing components and water, a reaction occurs with the release of gas, forming voids, the number of which determines the weight, density, thermal conductivity of concrete and areas of use:
- Concrete with a density of 300-400 (kg/m3) is used for thermal insulation.
- Density 500-900 (kg/m3) allows it to be used for constructing partitions and walls.
- With a density of 1000-1200 kg/m3, concrete is used to make load-bearing walls.
Concrete has gained popularity in housing construction due to its properties:
- Low thermal conductivity allows it to be used as a heat-insulating substance.
- Frost resistance can reach 150 cycles; among lightweight concrete, only expanded clay concrete has greater durability.
- High fire resistance.
One of the negative qualities for construction is hygroscopicity, which means that aerated concrete needs a coating.
The hygroscopicity of aerated concrete requires isolation from moisture.
Preparing gas silicate blocks indoors for plastering
In aerated concrete the amount of cement is up to 60 percent, in gas silicate concrete no more than 14, lime is twice as much, the rest is sand. The percentage matters because the more cement, the higher the strength, and the base must be stronger than the coating, otherwise it will peel off. That is, the finishing of the house must be done with a lime-cement composition.
When finishing, you need to remember that the base must be stronger than the coating.
The main function of plastering surfaces made of gas silicate blocks is to form a vapor-impenetrable barrier and limit moisture absorption. To improve the adhesion of the coating to the base, the structural elements are coated with a deep penetration primer, the first layer is applied generously, preferably with a spray gun, after drying it must be painted over again.
After priming, given that the gas silicate composition of the base is weak, it is necessary to carry out reinforcement to prevent the appearance of cracks.
The rough layer of reinforcement is made from the glue on which the blocks were laid; experienced craftsmen use tile adhesive for this as a cheaper composition.
The use of glue instead of a conventional solution is due to polymer additives in the composition, which ensure strong adhesion with a thin layer of the mixture.
After applying a thin layer of glue, 2-7 millimeters thick, a fiberglass mesh is embedded into it, which fixes the blocks and serves as a reliable base for the coating. The mesh is overlapped over the applied glue and pressed in with a notched spatula.
It is advisable to start applying the solution after 5-7 days, when the reinforced layer gains strength.
Plastering gas silicate blocks inside a building: technologies used
Protection of gas silicate structures occurs in three stages:
1.Plastering lime- cement mortar.
2.Priming.
3. Putty.
A lime-cement or lime-gypsum mortar no more than one centimeter thick is applied to the reinforced surface.
Technology hand plastering ordinary, if the wall is large and uneven, install beacons and level the applied layer using a broad rule.
The solution is mixed in a bucket, small tank or trough, water is poured into the poured mixture and stirred to the required consistency, you need to cook a little, gypsum sets in 20 minutes, cement needs a little more time, so the amount should be sufficient to be processed during this time. You can level it immediately after laying it on; the last step is grouting.
After finishing, use a long strip to check the evenness of the surface; unevenness within 5-7 millimeters will not be noticeable.
Is it necessary to plaster the aerated concrete block from the outside?
The need to protect the façade made of aerated concrete is due to its properties:
- Hygroscopicity will lead to saturation of gas blocks with water, which in frost will cause destruction of the structure.
- Mechanical impact will cause chips, dents, and cracks.
- The material has a porous structure with open pores through which circulating air carries away heat.
- Rough aerated concrete house looks unpresentable.
For aerated concrete structures, the danger is the accumulation of moisture inside the blocks, which freezes and destroys the block from the inside due to temperature changes. Therefore, protection of external surfaces is mandatory; the plastering method of protection is widely used due to various reasons, one of which is the low cost of this technology.
Materials used for exterior work
To apply protective agents externally, substances with the following qualities are required:
- permeable to water vapor;
- not getting wet;
- with good grip;
- resistant to frost.
The main types of mixtures for finishing aerated concrete outside:
- Acrylic for aerated concrete, strengthens loaded structures, base.
- Silicate, include liquid glass;
- Silicone, based on silicon-organic polymers, is well suited for facades, but high in price;
- Gypsum mixture;
- Lime-cement composition.
Do-it-yourself internal plaster of aerated concrete block: features of the work
Due to the high hygroscopicity of the material, plastering inside the house has its own characteristics.
Plastering surfaces must necessarily include a reinforcement process. It is recommended to use fiberglass mesh, which does not break down in an alkaline environment.
The surface should be painted with a deep penetration primer twice.
Apply a thin layer of plaster about 5 millimeters thick and embed the mesh in it. After drying, apply the base coat using beacons.
Which is better plaster
If vapor permeability is required for the kitchen, bathroom or sauna, mixtures of gypsum with perlite sand are used. Silicate is also suitable, but it must be taken into account that such mixtures are incompatible with acrylic, silicone, and latex materials.
For use on aerated concrete, you can use cement-lime mixtures, which do not require priming of the walls.
Tool set
Finishing aerated concrete surfaces requires the following tools:
- Spatulas.
- Scraper to remove dirt and debris.
- Metal brushes.
- Hammer for knocking down irregularities and protruding mortar.
- Sandpaper.
- Brushes, rollers for priming.
- Trowel.
- Tank for mixing the solution.
- Mixer for preparing the solution.
- Falcon, shield where the mixture is applied.
- Grout grater.
- Poluterok.
- The rule is to align the corners.
How to plaster: progress of work
Ready-made mixtures are great for finishing, but have a high cost, so for do-it-yourself wall preparation technology is proposed, after which you can safely use any composition.
For preparation you will need tile adhesive, fiberglass mesh, and deep penetration primer. It is necessary to smooth out all chips and cracks with a compound for laying aerated concrete blocks, then remove dust and debris from the wall with a cheek and paint it with a deep penetration primer twice.
Tile adhesive is diluted and applied to the surface with a thickness of 5 millimeters, the mesh is pressed on top with a notched trowel. When the layer is completely dry, apply plaster in the usual way, any solution can be used.
The costs of this technology will be an order of magnitude less than when using ready-made plasters.
How long before you can move on to the next stages of wall finishing?
After completion, the beacons are removed, the resulting dents are subsequently sealed with putty.
To move on to the next types of finishing, you must wait until the walls are completely dry at a constant temperature. Drying will require about a month during the warm season to ensure that temperature changes do not lead to cracking or peeling. It is not advisable to speed up the process; if necessary, a heater is used.
Interior and exterior finishing of a house is an important stage of construction work, the quality of which determines the durability, comfort of living and aesthetic appearance of the house. There are many modern materials and technologies available for finishing work, but traditional methods, do not lose popularity and are still relevant today. These methods allow you to achieve the necessary results at low cost and labor intensity.
Useful video
When building walls.
Aerated concrete and aerated silicate are modern building materials that are similar in structure to foam concrete, but differ in the structure of air bubbles inside the material.
Due to their hollow structure, aerated concrete and gas silicate absorb moisture well. Therefore, walls made of aerated concrete (gas silicate) cannot be left without exterior finishing.
Aerated concrete and gas silicate differ from each other only in that gas silicate is made from lime and quartz sand, and aerated concrete is based on cement (50-60% by weight). The basic physical characteristics of both materials are very similar.
In this article, let's look at the basic requirements for plaster used for finishing aerated concrete walls.
What is the difference between aerated concrete and foam concrete?
In foam concrete, the air bubbles are closed and isolated from each other, thereby significantly increasing its ability to resist getting wet.
Aerated concrete, on the contrary, has an open structure of air bubbles, due to which moisture quickly penetrates into the material.
It is because of this that aerated concrete has lower resistance to heat transfer and frost resistance and requires high-quality external and internal finishing, which allows minimizing the disadvantages of the open porosity of the material.
Let's see how to properly plaster walls made of aerated concrete and what plasters should be used for this.
When is the best time to plaster aerated concrete walls?
Many craftsmen begin plastering immediately after the walls are erected. In the case of aerated concrete, this can lead to many different problems.
When constructing walls made of aerated concrete, it is best to apply plaster for the next season.
If it is necessary to carry out finishing immediately after construction, then you should carefully consider the choice of plaster, which should have high ductility and easily allow water vapor to pass out.
A feature of the thermal physics of aerated concrete is its rapid wetting, long drying time and the inadmissibility of oversaturation with water vapor.
When constructing buildings made of aerated concrete, it is recommended to carry out the interior finishing first, and only then the exterior. For example, interior decoration perform it in the fall, and external plastering in the spring of next year.
Rare exceptions may be houses built on the sea coast, when it is necessary at all costs to first protect the aerated concrete walls from the wet wind.
Another option for finishing would be to simultaneously finish the outside and inside. But this option is the least preferable.
There's no need to rush. After construction, the aerated concrete must dry well, but this is not a quick process. As a result of finishing wet aerated concrete walls with heavy cement plaster during the cold period, when the inside of the building becomes warm, water vapor begins to move to the outer edge of the wall.
But due to severe vapor-tight plaster they have nowhere to go and water vapor falls out in the form of condensation, the freezing of which can lead to complete separation of the plaster from the wall.
A particularly unfavorable time for plastering walls made of aerated concrete blocks is the period from November to March.
Is it necessary to insulate aerated concrete walls from the outside?
When making walls from aerated concrete blocks, their thickness is calculated based on local climatic conditions. As a rule, a correctly selected wall thickness does not require external insulation. Moreover, in some cases this can lead to the destruction of the building.
To insulate walls, many advise using polystyrene foam, believing that this will improve the thermophysical properties of the building. However, a material impermeable to water vapor can cause condensation at the boundary of the insulation and masonry from water vapor released from the aerated concrete blocks. Freezing of condensate can lead to the appearance of cracks in the walls and subsequently to their destruction.
That is, you should not take the thickness of the walls so that they still need to be insulated. Aerated concrete has high thermal characteristics and does not require the construction of thick walls to save heat inside the building.
So, for country houses in middle lane a wall thickness of 300 mm made of aerated concrete will be quite sufficient. To build a bathhouse, a wall thickness of 200 mm is enough, and more warm regions- 100 mm.
In the case of insulating a building using the external laying of a layer of polystyrene foam, its thickness should be chosen so as to prevent condensation from falling out at the boundary of the masonry and insulation. The thickness of the insulation layer made of polystyrene foam or polyurethane should be at least 80 mm, and the thermal resistance of the insulation layer should be at least 50% of the total thermal resistance of the wall.
How to plaster aerated concrete?
It would seem that the easiest way is to prepare a regular cement-sand mortar and plaster the walls. But this may cause problems, which were already mentioned above.
As a result of the different physical properties of cement plaster and walls made of gas silicate blocks, cracking and peeling of the plaster can occur.
Plaster for aerated concrete must be highly permeable to water vapor, not get wet, have good adhesion to the surface of aerated concrete blocks and high frost resistance.
Lime-cement plaster for aerated concrete
Lightweight thin-layer plasters, specially created for finishing walls made of aerated concrete, have all the necessary properties.
An example is this plaster mixture– Baumit HandPutz sand-lime plaster for manual finishing with a grain size of 1 mm, available in 25 kg bags.
The main physical properties of lime-sand plaster for aerated concrete are given in the table:
|
Indicator |
Meaning |
|
Grit size, mm |
|
|
Compressive strength (28 days), N/mm 2 |
|
|
Tensile strength in bending, N/mm 2 |
|
|
Thermal conductivity coefficient λ, W/mK |
|
|
Vapor permeation resistance coefficient μ, |
|
|
Density of dry mixture, kg/m3 |
|
|
Water consumption, l/bag |
|
|
Material consumption (with a layer thickness of 10 mm), kg/m2 |
|
|
Minimum thickness of plaster layer, mm |
|
|
Maximum thickness of plaster layer, mm |
Before plastering aerated concrete walls with this plaster, it is recommended to spray the cleaned surface of the aerated concrete with Baumit Vorspritzer, which is part of the plaster, which is made as a thin adhesive joint.
Acrylic plaster for aerated concrete
For a more decorative finish, acrylic plasters are used. This is a very durable material that can be used wherever increased strength is required.
However, acrylic plasters are inferior in vapor permeability to lime-sand plasters, and as a result of finishing with such plaster, water vapor can accumulate in the thickness of the wall.
To prevent this, you should use enhanced waterproofing of the wall with inside, as well as an improved ventilation system.
In addition, acrylic plasters are flammable and therefore used with restrictions.
An example of acrylic plaster for aerated concrete is Bolix and Bolix Complex plaster.
Silicate plaster for aerated concrete
There are also silicate plasters for aerated concrete. An example of such plaster is the ready-to-use paste mixture Baumit SilikatTop based on potassium liquid glass.
Silicate plasters have excellent vapor permeability and low water absorption, which is very important when finishing walls made of aerated concrete blocks.
The disadvantages of such plasters include an extremely meager choice color solutions and loss of appearance due to dust settling on the surface of the plaster.
Silicone plaster for aerated concrete
Another type of plaster mixtures used for finishing walls made of aerated concrete blocks is silicone plaster based on silicon-organic polymers.
Silicone plaster is resistant to atmospheric influences, it practically does not get wet (hydrophobic), has high vapor permeability, is easy to apply and does not lose its attractive appearance over time.
The only disadvantage of such plaster is the higher price. Such plaster can no longer be classified as “economy class”.
Plastering walls with lime-sand plaster
When using the Baumit HandPutz mixture, the sequence of actions will be as follows.
A bag of mixture (25 kg) should be poured into a container with 6-7 liters clean water and mix thoroughly with a low-speed mixer. Mixing time is 3-5 minutes.
After this, spray Baumit Vorspritzer on the wall, which promotes better adhesion of the plaster to the surface and reduces moisture absorption of aerated concrete.
A layer of plaster is applied with a trowel and pulled out using a rule. After setting, it is rubbed with a grater.
For 2 days, the applied plaster should be protected from rapid drying.
The hardening time of the layer is 10 days per 10 mm thickness. At this time, the plaster should be protected from mechanical damage.
All work must be carried out at an air temperature not lower than zero degrees.
For better protection to prevent it from getting wet, you can apply a thin layer of water repellent on top of the plaster. If prolonged rains are frequent in your area of residence, then such a protective layer will significantly extend the service life of the plaster.
In the next publication we will look at the plastering process in more detail.
The plastering process is the most common type of exterior finishing. It is used to level walls interior space. However, how different is the technology for applying the material if it is necessary to plaster aerated concrete or brick walls? Or maybe you are the lucky owner frame house or buildings made of foam blocks. Today I will talk about the basic principles of applying plaster to walls with my own hands, and we will also look at how the foundation of a house is plastered.
The need for plaster for a brick house
It doesn’t matter if the old one is being renovated brick building or walls are decorated new construction, plaster is a necessary element for quality work. Using modern plaster, you can carry out high-quality protection of walls from negative atmospheric influences.
Important! Using a traditional mixture made with your own hands, it is better to treat fairly large surfaces. Modern materials contain components that increase beneficial properties plaster.
The material that will be used for external surfaces must meet important requirements:
- The material must be moisture resistant and vapor permeable. If the plaster does not remove accumulated condensation, the walls will begin to collapse very quickly and the house itself will not stand for long
- Must be resistant to atmospheric conditions - that is, if an external mixture is used, it must withstand sudden changes in temperature and frost
- Mechanical resistance is important criterion, since the surface of the walls is often subject to unintentional impacts and weather disasters
Brick walls are plastered during reconstruction work, as over time, cracks, chips, or simply due to uneven masonry during the construction of the house appear on the walls of the house. Brick house You can plaster it yourself and to do this, just follow this sequence:
- Before starting the work process, the surface should be cleaned of dirt and dust. Then sprinkle it with a solution of cement and lime. In some cases, only cement mixture can be used
- The next step is priming
- Apply a covering layer
- To perform the work efficiently, beacons are installed with your own hands, and a plaster solution is applied between them. Try to apply the material as evenly as possible
- Using a trowel, level the surface and check with a level
- The beacons are dismantled, and the remaining voids are sealed with mortar.
- Before completion, the surface of the walls is sprayed. The resulting finish is sprayed with water for three days. If possible, the base is hidden from straight lines sun rays, which can speed up the setting process and thereby reduce the performance of the material
A brick house often requires additional thermal insulation, which can occur using the well-known polystyrene foam. In this case, subsequent plastering is a necessary step.
Foundation protection
The foundation of the house is the most important place of the entire structure, which is most exposed to negative impact. Protection of the foundation using plaster should be carried out at the highest level and, most often, you should contact specialists for this. But if you want to plaster the foundation with your own hands, then follow this plan:
- All contaminants must be removed and scored. It is performed for a foundation that has stood without covering for more than a year.
- Elimination of defects - all weak points are beaten back to a solid basis
- A layer of primer is applied to the surface of the foundation
- Defects and potholes along with seams are filled with cement mortar
- Install the chain-link mesh using dowels
- Install beacons
- Plastering is carried out in 2 layers - the first is the primer, and the second is the finishing
- The first layer should dry well, only after that the second is applied - usually the drying time reaches 5-7 days. In this case, the surface is periodically sprayed with water.
- The decorative layer is applied to the wet foundation with a thickness of about 5 mm. It is important that this time the mixture is thicker and more flexible
Various types can be used as a finishing layer for the foundation. decorative plaster. For the foundation, a mortar with a “travertine” texture, terrazite plaster and fur coat are suitable. It is important that the finishing of the foundation coincides with general design facade.
Plastering foam concrete
Being quite light and durable material, foam concrete is in great demand for house construction. The advantages of foam blocks have long been justified, one for long term service, the surface of the foam blocks must be plastered both outside and inside the house.
The technology for plastering foam block walls does not differ from the processes for other types of surfaces. However, to achieve maximum effect, you should use some tips:
- Like any base, the surface of the foam block must be primed. To do this, it is best to choose a deep penetration primer and apply it in two layers. Thus, the adhesion of the foam block and plaster will be maximum
- Before plastering the walls of a foam block house, you should install a reinforcing mesh. Monitor its condition - there should be no breaks
- When choosing foam blocks in a hardware store, you should pay attention to the color of the material. Foam block products must be gray, the advantage of yellow will indicate a large amount of sand. This will make the material very fragile.
- If the base of the walls is made of cast foam block, then use fiberglass rather than construction mesh
When doing work with your own hands, you should give preference only to quality materials, which will allow you to complete the finishing process as quickly, efficiently and for a long time as possible.
Facing a frame house
For a frame house, plaster is used as often as panel siding. Before performing work on the outside of the house, you should choose a plastering method:
- Using cement bonded particle boards
- Using multilayer reinforced plaster using metal mesh
If the finishing of a frame house will be carried out once every 5-7 years, then you may well choose the first option. It is easier to do with your own hands. However, by spending more time and effort on the second method, you will get a façade of a frame structure that will last at least 13-15 years.
If it is planned to use decorative plaster for a frame house, then one layer of the mixture can be applied over the construction mesh. In the case of a single-layer application, clinker, as well as ceramic tiles or stone, can be used for the frame structure.
Important! A water repellent is used for plasters to enhance the water-repellent properties of a frame house. With their help, gas permeability remains the same, but moisture absorption is significantly reduced.
For a frame house and covering it with plaster, all bases must be treated. However, in some cases it is allowed to coat only those surfaces that are most susceptible to moisture.
Self-clad aerated concrete
Finishing aerated concrete with plaster
Aerated concrete is in demand building material, which is used in low-rise construction. Popularity this material received thanks to its light weight and speed of construction of houses with its help. However, with such positive qualities, aerated concrete has a low thermal conductivity coefficient and therefore requires high-quality finishing.
Important! The microclimate created inside a house made of aerated concrete is comparable to the microclimate wooden buildings. Therefore, plastering aerated concrete walls is necessary in the same way as plastering wooden house outside.
Aerated concrete inside the house must be plastered using certain solutions. The use of a cement-sand mixture is unacceptable, since the material has the property of absorbing moisture. Aerated concrete is best finished with gypsum putty or gypsum-based solutions. Inside the house, you can use solutions with fillers such as chalk, marble or dolomite.
Important! On the modern construction market there is a special plaster with which cellular material can be finished without compromising the vapor barrier properties.
To maintain a vapor barrier, aerated concrete can be finished with plastic film. However, if all the work is carried out incorrectly, condensation may appear on the surface of the walls, and the plaster will swell over time. This is why many people decide to plaster aerated concrete using sand-cement mortar, but even in this case the coating will definitely begin to peel off. Before you start finishing aerated concrete, you should study in detail all the pros and cons of these methods and only then decorate the walls inside and outside the house. Aerated concrete has different brands density and you need to remember that the plaster is selected based on these data. Exterior plaster can be done independently at home; all processes must take place in the warm and dry season.
Color of plaster mixture
Plastering aerated concrete walls inside the house
The use of decorative plaster is in demand due to the ability to choose the desired color of the material. Due to the fact that there is a huge number of plasters that have color, creating a specific design and its shades becomes quite simple action. In addition to using ready-made mixtures, you can add pigment when self-production solution. However, having given a certain color in one batch, there is no guarantee that the color of subsequent batches will completely match. Even when using the same proportions, there may be a slight color change that will be noticeable on the walls inside or outside the house.
In specialized stores you can choose the color of plaster you need thanks to the palettes of certain manufacturers, and also decide on the shade along with catalogs of houses already finished using these materials. Remember, the richer the tone of the plaster, the longer the color will last. At the same time, rich dark color can very quickly lose its appearance.
The construction of houses from gas silicate blocks is one of the most promising areas in the field of private construction. In particular, they have gained great popularity aerated concrete blocks, during the production of which special additives are introduced into the solution, causing abundant gas formation. As a result, aerated concrete has a pronounced open porous structure, which determines its significant advantages over other materials for masonry walls.
However, such a structure of aerated concrete also brings a number of difficulties in finishing the constructed walls. This requires a special approach, both in the sequence of work and in the materials used. In addition, the plastering of aerated concrete walls indoors will also depend on their planned exterior decoration.
What is the “capriciousness” of aerated concrete in matters of finishing, and how can these problems be solved? These are the issues that this publication is devoted to.
Features of aerated concrete
But you should go through the materials for the work in more detail.
- The open porous structure of aerated concrete will not allow you to limit yourself to just filling the walls - a thin layer simply will not stay on such a surface. Therefore, even if the wall is lined with highest precision and does not require special adjustments to its plane - you still can’t do without plaster. And on aerated concrete wall you will have to “throw on” a layer of at least 5 mm.
- Such a layer will be subject to cracking and crumbling (affected by the adhesive properties of the highly porous structure) if it is not reinforced with a reinforcing mesh. If on others wall materials the use of reinforcing mesh is desirable, but in the case of aerated concrete this condition should be considered as mandatory. The best mesh is fiberglass, resistant to an alkaline environment, so that over time it simply does not dissolve in the thickness of the hardened plaster mass.
The use of reinforcing fiberglass stacks is a prerequisite for high-quality plaster - Aerated concrete walls have high moisture absorption. As experienced painters say, this material literally “drinks” water. It would seem that this is not bad for good adhesion, but it turns out just the opposite. Aerated concrete “sucks” moisture from the applied material, which causes it to quickly dry out, crack and crumble - in the case of gypsum compositions, and disrupt the normal hydration of cement if plasters based on it are used. In both cases, the quality of the coating will be low, and the finish itself will be extremely short-lived.
It is important to find the right “humidity balance”, otherwise the work will be of poor quality On the other hand, excessive saturation of aerated concrete with water is also fraught negative consequences. And such a wall is very difficult - the applied solution begins to “creep”, the layer becomes loose or heterogeneous, etc.
What's the solution?
— you can use special plaster mixtures specifically for aerated concrete, intended for interior finishing work. Their component composition, when properly mixed with water, in accordance with the instructions, is completely optimized for the characteristics of such a surface and sometimes does not even require preliminary priming of the surface. All this is necessarily indicated by the manufacturer in the instructions for use of the composition.
- use of special deep penetration primers. Here, however, balance is also important - oversaturation of aerated concrete with impregnating compounds can lead to the opposite effect, since the absorbency of the surface for applying plaster to it is still important.
In both cases, professional craftsmen do not advise immediately giving a thick outline - it is best to limit yourself to a minimum layer in which the reinforcing fiberglass mesh is embedded. Such a layer does not require a large amount of moisture, it is much easier to “grind” it into aerated concrete with force, and the reinforcement will create a strong base, without cracks. But after such a substrate has dried, you can safely move on to the main plastering on the beacons.
Video: the work of a master plastering an aerated concrete wall
As already mentioned, the composition of the plaster mixture directly depends on whether the wall needs to retain its high vapor-permeable properties, or, conversely, to make it as difficult as possible for the penetration of moisture into the material.
- In the first case, preference is often given to special gypsum-based plastering compositions, which often include light perlite sand. Usually, the instructions for use of the composition indicate that it is combined with aerated concrete (gas silicate) walls. A classic example of such mixtures is Plaster or Osnovit-Gipswell plasters.
Manufacturers claim that applying such compounds does not even require a reinforcing mesh. But in the case of aerated concrete, it is better not to ignore this point.
- Silicate plasters, based on , are very well suited for aerated concrete, especially in terms of vapor permeability. However, such wall decoration will significantly limit the owners in choosing a finishing coating, since silicate mixtures are incompatible with many other decorative compositions on an organic basis - acrylic, silicone, latex, etc.
- Cement-lime based plasters have been developed specifically for aerated concrete or similar surfaces. Their composition is optimized specifically for such surfaces that do not even require preliminary priming before plastering works. An example is Baumit HandPutz plaster or a mixture from a set of a whole “ensemble” of solutions specially designed for AeroStone aerated concrete.
The composition of such plasters includes cement, building lime, special lightweight aggregates and plasticizing additives, and fine-grained purified sand. This coating has good vapor permeability and can be used for both external and internal work on aerated concrete.
- If the owners of the house plan to achieve minimal vapor permeability of the walls from the inside, then they usually resort to using cement-sand plasters without the inclusion of lime or dolomite chips (flour). Naturally, the composition usually includes special plasticizing additives that inhibit adhesion created coverage with a porous base.
All specialized mixtures for gas silicate surfaces have one general disadvantage- they are quite expensive, and with large volumes of work, such internal plastering of walls will result in a hefty sum. But this is only preliminary alignment, without taking into account finishing! Is it possible to do something simpler, use more affordable mixtures or even ordinary homemade plaster solutions, for example, based on cement and sand?
It is possible, but such finishing can only be done qualitatively experienced master, whose long-term practice allows him to “by eye” determine the condition of the wall, the need for it to be moistened or primed, and the exact component composition of the plaster. And without experience in such work, make a mistake on aerated concrete surface- as simple as shelling pears, and all the work will be done down the drain.
However, we can highly recommend interesting way preliminary preparation gas silicate wall to further. If you do everything in accordance with the recommendations, you can apply almost any plaster composition without fear of cracks appearing, the solution slipping, its rapid drying out, or, conversely, excessive waterlogging of the wall.
How can you properly prepare an internal aerated concrete wall for plastering?
To work you will need ordinary, the most inexpensive of all those presented in the store, glue for ceramic tiles, fiberglass mesh, deep penetration primer (regular, type Ceresit CT 17). And then it will be possible to plaster with any composition on gypsum, cement, cement-lime and other bases. In particular, the usual cement-sand mixture, even in a ratio of 1:5, is quite suitable.
Determining in advance the amount of plaster mixture to put the wall in order is quite difficult, since it depends on the condition of the surface, its evenness, the presence and depth of level differences both vertically and horizontally. But our calculator will help you determine the amount of materials for the preparatory cycle.
It takes into account the conditions for priming the surface in two layers, with the primer being diluted with water during the initial application, and the creation of a preparatory reinforced adhesive layer 5 mm thick. Calculations will show the result with a 15% reserve “just in case” accepted among builders and finishers.
The calculation is carried out for rectangular surfaces, excluding window and door openings.
