How to plaster an old stove so it doesn't crack. How to plaster the stove so that it does not crack? Heat-resistant plaster for stoves and fireplaces: tools, technology

Stone and brick stoves are plastered to prepare them for decorative cladding. It is also needed to increase the tightness of the masonry. The success of the finishing work depends on the competent choice and preparation of the material. What is the best solution for plastering the stove and how to make it, this article will tell you.

Which material is better

The plaster for the oven must meet certain requirements. General construction cement-sand mixture for the preparatory lining of heating equipment is not suitable:

1. When the oven heats up, the material with which it is plastered expands. The cement mixture is not elastic. Therefore, at high temperatures, it will begin to crack. Full information on the composition and characteristics of cement can be found.
2. Some additives used to improve the performance of cement slurry release toxic substances when heated.
3. In order for the stove to quickly and efficiently heat the dwelling, its preparatory lining must have sufficient thermal conductivity. With pure cement, it is too low.

The best solution for plastering oven walls is a clay-based mixture. This composition can be simple or complex. The solution can be made independently or purchased in the construction market ready-made dry mix in bags.

To increase thermal conductivity and resistance to high temperatures, the following ingredients are added to the plaster composition:

• fire-clay;
• asbestos fibers;
• chamotte;
• glass fiber;
• salt.

The optimal composition for facing should have the following properties in the hardened form:

• environmental friendliness, it should not contain synthetic and toxic substances;
• resistance to high temperatures, not chipping or cracking from them;
• high thermal conductivity.

The composition of the mixture

The main quality of the preparatory facing layer for the oven is its resistance to temperature extremes.

It must withstand regular heating and cooling without destroying the structure. Therefore, special requirements are imposed on stove plaster in terms of quality and components.

There are many types of mortars that can be used to coat a home heating device. A simple mixture is often used. It consists of clay of different fat content and river quartz sand. It is easy to knead such a solution with your own hands and apply to the oven.

There are also complex mixtures, they can consist of the following components:

• gypsum and lime;
• clay, sand and cement;
• sand, clay and lime;
• gypsum, lime, sand and fiberglass;
• sand, plaster, lime and asbestos.

Material proportions

You can plaster a brick stove 30 days after it is folded. This pause is necessary so that the masonry mortar is completely hardened and the structure shrinks. Read how to make lime-based plaster yourself. If you start plastering work earlier, then the period of operation of the finish will decrease and there will be a risk that the plaster will begin to crack, flake off.

A correctly mixed clay mixture will guarantee that the heating structure will be reliable and will last for a long time. To make a high-quality mortar for plastering the oven, its proportions must be precisely observed. Here they are:

• ordinary or refractory clay - 1 volume fraction;
• river quartz sand - 2 parts;
• asbestos or glass fiber - 0.1 share.

The proportions of the mixture depend on the fat content of the clay. When soaked, this material must have sufficient viscosity for easy application to the substrate. When the clay is very oily, then not two, but three to four volume fractions of sand should be added to the solution.

Particular attention should be paid to the reinforcing components of the mixture. Asbestos or crushed glass fiber will strengthen the plaster, therefore it must be included in its composition. Some experts add chopped straw or chopped hemp to the mixture. Their ecological purity is beyond doubt. Whereas asbestos is hazardous to health under certain conditions.

In addition to a simple mixture, complex analogs are made on the basis of clay with the following proportions:

1. Portland cement M-400, ordinary or refractory clay - 1 part each, quartz sand - 2 parts, fiberglass or asbestos - 0.1 part.
2. Slaked lime, clay - 1 part each, sand - 2 parts, fiberglass or asbestos - 0.1 part.

In addition to clay and Portland cement, gypsum and lime are used for plastering ovens. The most common recipe for a mixture based on them:

• slaked lime - 2 volume fractions;
• separated building gypsum - 1 part;
• river quartz sand - 1 share;
• glass or asbestos fiber, chopped straw, hemp - 0.2 parts.

When mixing the solution, it is important to remember that the gypsum sets instantly. This happens in 5-7 minutes, after half an hour the material has already hardened completely. Therefore, it is necessary to work quickly with a gypsum solution. The instant hardening of the gypsum makes it an optimal additive for lime-based mixtures, increasing the durability of the plaster.

DIY stove plastering solution: step by step instructions

Self-cooking technology plaster mix depends on its composition and proportions.

Clay solution

First, pick up the clay itself. For cladding ovens optimal choice will become yellow, not very greasy material.

1. There should be no foreign inclusions in the clay - debris and stones. Therefore, grind it and sift it through a fine steel mesh.
2. Next, pour the clay into a suitable container and fill it with water. The material will be saturated with it and become homogeneous. Clay acidification time is about a day.
3. Prepare river quartz sand - dry it, and then sift through a fine sieve.
4. Quench the lime carefully. To do this, put it in a suitable container and fill it with water. By the time the solution is prepared, the chemical reaction should completely stop.
5. Place sand, lime, clay and asbestos fiber in a suitable container in a ratio of 2: 1: 1: 0.2. Stir the dry mixture well.
6. Then fill the solution with water. Stir it until the consistency is similar to sour cream.
7. After that, check the quality of the resulting material. To do this, dip a wooden slat into the solution. If there is a layer of solution less than two millimeters on the stick, add a little sand to the material. If the layer thickness is more than the indicated figure, add clay to the container.

To increase the quality of the mixture, it should not be prepared manually, but using an electric drill with a mixer attachment. So the solution will turn out to be homogeneous, without unmixed areas.

Cement mix

If you want to plaster the oven with cement mortar, then M-400 grade material is suitable for this. It begins to set after 20 minutes.

Slaked lime must be added to the cement slurry. Such a mixture will have sufficient plasticity and strength, it will be convenient to apply it to the base. Solution preparation algorithm:

1. First, dry cement is mixed with sifted river sand and asbestos in a ratio of 1: 2: 0.2.
2. One volume fraction of slaked lime is diluted with water to a creamy state.
3. Further, a cement-sand mixture is poured into it. All this is thoroughly mixed until smooth.

The plaster layer may flake or crack. This happens due to the incorrectly selected thickness of the joints between the bricks, their illiterate bandaging, or from overheating of the cladding.

To prevent this possibility, before plastering the stove, it must be covered with burlap. It must be soaked in liquid clay in advance. It is necessary to tighten the walls of the structure so that there are no air bubbles between them and the burlap.

Non-woven fabric can be replaced with a metal mesh with meshes of no more than 5 × 5 mm. It should be fixed to the bricks with a thick (3 mm) steel wire. It must be laid in brick rows during the construction of the stove.

When the plaster layer is completely dry, you can apply liquid diluted lime with an admixture of 0.1 part of salt. After this treatment, the cladding becomes stronger.

It does not matter what kind of solution you coated the heating structure, the quality indicators of the plaster should be as follows:

1. The deviation of the furnace plane from the vertical along its entire height should not exceed 5 mm.
2. Horizontally, this value should not be more than 2 mm.
3. Deviation from a straight line of thrust between the outer corners - no more than 0.3 cm.
4. Differences in height when the rule is applied to the walls of the structure should not be more than 1 mm for each meter of its surface.

The stove can be plastered with mortars of different materials. However, a clay-based mixture is best. The main thing when preparing such a solution is to accurately observe the proportions of the components and mix the composition thoroughly. It is necessary to apply the cladding so that the coating is as even as possible.

For more information on the topic of this article, watch the video. It describes in detail the preparation of plaster mortar for ovens.

For a high-quality repair, you should know how to properly prepare a solution for plastering the oven with your own hands. If everything is done properly, the stove will last a long time and will not require restoration. Below we will consider the "recipes" for the preparation of clay solution.

Collapse

Compound

There are many recipes for preparing a solution, the composition of a mixture for plastering a furnace can be combined into one formula - a bonding material (clay, sand, cement, gypsum) and water. At the same time, clay is a fundamental component of any mixture, since it costs a penny and is easy to work with.

Plaster preparation options

There are several standard solutions that are used for plastering:

• Standard clay-sand;
• Cement-clay-sand;
• Lime-gypsum-clay;
• Gypsum-lime-sand.

Clay-sand

A solution for plastering a stove made of clay can be distinguished as one of the most popular, due to its simplicity and low cost. The amount of ingredients required is as follows:

• 1 part clay;
• 2 pieces of sand;
• 0.1 part of asbestos;
• pure water.

The proportions of sand and clay for plastering the oven are approximate and can be changed during the preparation process.

Cement-clay-sand

To increase the strength and hardness, a part of the cement is added to the solution to the clay and sand.

• 1 part cement;
• 1 part clay;
• 2 parts river sand;
• 0.1 part of asbestos and fiberglass;
• pure water.

But there is one drawback, the solution must be worked out quickly, otherwise it will dry out and become unusable. Cement should be chosen of good quality, so that it is not damp and crumbles well.

Lime-clay-sand

Slaked lime is added to the standard batch to facilitate the work. The solution becomes more plate-like and has an attractive appearance.

• 1 part slaked lime;
• 2 pieces of sand;
• 0.1 part of asbestos;
• pure water.

Gypsum-lime

The solution must be kneaded a little, as much as you can spend in a small area. Better to cook again.

• 2 parts of slaked lime;
• 1 part of construction gypsum;
• 1 part sand;
• 2 pieces of asbestos fiber;
• pure water.

Gypsum tends to harden quickly, so the ready-made solution must be worked out within 30 minutes.

To avoid cracking, heat the oven slightly before applying the mixture. This applies to all types of solution.

Why is asbestos fiber added to the solution?

To impart plasticity and strength to the mixture, asbestos fiber is used. Some craftsmen use straw or burlap fibers, explaining that the products are environmentally friendly. This component also carries heat-shielding functions.

When added to the mix, it forms a thermal film that prevents cracks in the plaster. The more asbestos is added, the higher the thermal conductivity. The asbestos mixture is resistant to moisture, low temperatures, fireproof and durable.

Solution requirements

A well-prepared solution is the basis for long use ovens. Before choosing a mixture, check out the main characteristics that you need to focus on when buying:

1. Heat resistance. The basic and main requirement, after which the rest are not so important. The applied solution must be able to withstand high temperatures - up to 95⁰С.
2. Thermal conductivity. The stove, as a source of heating, when a certain temperature is reached, must give off heat to the interior of the premises.
3. Elasticity. When heated, the applied coating should give in to some stretching. Thanks to this, the plaster layer will not burst, preserve its appearance and prevent subsequent restorations.
4. Environmental friendliness. The composition of the solution should not contain toxic chemicals, since when heated they will be released into the air, which is not good for premises.

Conclusion

In conclusion, we can say that the observance of the proportions of the components and the fulfillment of all requirements are the basic rules for plaster. When choosing components for the solution, take responsibility and keep in mind that the durability of the coating and the health of people depend on it. If you are not entirely sure which materials are suitable, consult a specialist. They will pick up everything you need and give you a consultation.

← Previous article Next article →

Brick and stone stoves are plastered in order to prepare the walls for further decorative finishing and to increase the tightness of the masonry. Independent plastering of the stove is within the power of every home craftsman, but 80% of success lies in the right choice and kneading the plaster mixture. What solutions are suitable for furnace equipment and how to apply them correctly - this knowledge is the key to success and a guarantee of long-lasting results.

How to plaster the stove: tradition and innovation

Standard cement mortar for finishing stoves and fireplaces will not work. Firstly, high temperatures will lead to cracks, and secondly, not all components of modern plaster mixes are safe after heating - some components emit unpleasant-smelling and harmful substances.

What are the solutions for ovens

Traditionally, for plastering heating equipment, clay mixed with sand, straw, sawdust, and salt was used. Now, for plastering stoves with their own hands, they use not only recipes that have come from time immemorial, but also modifying additives that improve adhesion to the surface and resistance to sudden temperature jumps.

The most popular among stove-makers are lime-clay, lime-gypsum and cement-clay-sand mortars. You can make plaster for stoves and fireplaces yourself or buy ready-made heat-resistant mixtures in stores. For beginners, it is better to stop at the factory formulations and strictly follow the manufacturer's instructions.

Ready mixes guarantee the correct solution

Popular recipes for clay plaster mixes

Clay is characterized by high thermal conductivity and has a nature similar to brick, therefore, on its basis, an ideal plaster for a brick oven is obtained. Before mixing the solution, the clay is soaked for two days in settled water, and then passed through a sieve.

The amount of sand in the solution is on average twice the volume of clay, but it is always specified empirically - the higher the fat content of the clay, the more sand is required. The solution should be thick, but plastic. For a bundle, sawdust, crushed fiberglass or asbestos are added to it.

The solution must be thick and plastic

In addition to the clay-sand mortar, for plastering the furnace with their own hands, they use compositions with additives that increase the strength and durability of the structure. Here are proven recipes from stove-makers:

1. Combine one part of clay with two parts of fine sand mixed with a tenth of fluffed asbestos.
2. Take clay and lime in equal portions, combine them with two portions of sifted sand and a tenth part of asbestos.
3. Mix in equal volumes of sand and gypsum, add two proportions of lime, a fifth of asbestos and one part of clay.
4. In a mixture prepared from one portion of cement, add two parts of sand and a tenth of asbestos. Clay will be required as much as cement.

All components are sifted through a fine sieve before preparing a solution for plastering ovens. Professional stove-makers mix the dry ingredients first and then add them to the wet clay. Gypsum is preliminarily diluted with water and added to the mass as it works, since it hardens very quickly.

How to plaster a stove with your own hands: how to work

Plastering a new stove is allowed no earlier than a month after laying - during this time the stove will completely dry out and the process of shrinkage of the structure will be completed.

The surface of the oven is cleaned from the remnants of the masonry mortar

Preparatory stage

Before plastering the stove with your own hands, the outer surface must be cleaned of the remnants of masonry mortar, dust and other contaminants. The seams should be deepened by 5-10 mm - this will improve the adhesion of the plaster mixture to the masonry. Immediately before starting work, the oven should be well heated and then humidified immediately. You can use a water spray to moisten.

It is recommended to cover brick and masonry with a reinforcing mesh - this will increase the strength of the plaster layer several times, enhance adhesion and prevent cracking. The grid is used without fail if tiling is planned in the future.

Metal mesh increases the durability of the plaster

Sequence of plastering work

Plastering of red brick and stone stoves is carried out in several stages, during each of which one layer of mortar is applied.

1. Spray is the first thin layer, it is applied to the walls by a throw-in method without subsequent smoothing. The solution for this layer should be diluted with water until sour cream is thick. The task of the spray is to fill in the irregularities and prepare the base for the main layers.
2. The second layer is called a primer, it is applied immediately after the spray has set, without allowing it to dry out. The thick mass is spread over the surface with a trowel and leveled with a trowel. The thickness of the soil is 3-4 mm.
3. In conclusion, a thin layer of a thinner plaster mortar is applied with a float, a thin consistency helps to hide barely noticeable defects. The finishing coat is called a cover, its thickness is no more than 2 mm.

Instead of a simple cover, decorative plaster for the oven can be applied, replacing painting and cladding. In this option, stone, lime-sand, terrazite and other compositions with the addition of heat-resistant pigments are used for the finishing coat.

Typical problems and defects

If the plastering of the stove with your own hands was carried out with errors, defects will appear on the surface that require repair. When the mortar is applied to dry bricks, flaking is inevitable, and excessive moisture leads to flakes that require redoing the work after drying.

Dutik - miniature tubercles, appear due to the use of poorly quenched lime. In this case, extinguishing continues even in a dry coating, forming small swellings prone to shedding.

Cracks appear due to improperly mixed mortars. In most cases, oily clay, diluted with an insufficient amount of sand, is to blame. Also, the plaster can crack when applied too thick layers or as a result of insufficient adhesion of the previous layer.

To avoid mistakes when plastering stoves and fireplaces, beginners are advised to entrust the work to a professional master. Observing the process will help consolidate theoretical knowledge and next time do the work on your own.

Video: decorating the fireplace with decorative plaster

Plastering stoves with your own hands

Recently in country houses, at dachas and in baths it has become fashionable to make stoves in the old-fashioned way: to plaster with clay plasters and whitewash with chalk and lime. Natural ingredients, fresh smell, antibacterial effect from whitewashing - our ancestors knew a lot about useful properties building materials and healthy conditions stay!

Stoves without cladding do not look aesthetically pleasing, dust and debris collects in the seams of the masonry, which, not only is poorly cleaned, also spreads unpleasant odors, burning when the stove is heated. Plus, (especially if the stove-maker laid down the masonry very quickly, since his “pipes were on fire” and a legal hundred grams and a cucumber were waiting for him at lunchtime), a certain amount of smoke and carbon dioxide comes out through various microcracks in the seams formed by poor-quality masonry that are unhealthy. To avoid all of the above, furnace plastering, tiling, thin layer printed concrete, or other furnace finishes are performed that require some cost. Therefore, plastering the stove is one of the economical options.

If you are just planning to make a stove, and then plaster it and read this article, then it may be more expedient for you to buy an initially beautiful even brick or facing brick, lay the stove out of it evenly, in accordance with the building level and beautifully embroider the seams between the bricks, then it will initially look great, especially if you open it then with a special varnish for stoves on water based eg with a wet stone effect. This, perhaps (but not a fact), will cost a little more than a lined stove made of old or crooked bricks, which is then closed with plaster mortar, but then you will not need to fiddle with the stove plaster, and the stove itself will initially look very beautiful and constantly delight you with your appearance. In addition, you will avoid possible flaking of the plaster (occurring over time), as this often happens due to mistakes made when plastering the stove. But, if you already have a ready-made stove and, most likely, it is made of gnarled or old brick, then you cannot do without plastering the stove, which you can make with your own hands.

Durability Secrets for .
Why does the plaster fall off the surface of the stove?
Stove plaster flakes off mainly for the following reasons:
1) due to who made the oven - he could make the wrong thickness of the seams or bandaging the rows of bricks.
2) overheating of the furnace.
To prevent this problem, a thin steel reinforcing mesh is used, the mesh size of which is not more than 1 cm. The mesh is attached with a wire to the brickwork of the oven, with a wire 3 mm thick. It is advisable to start the wire in each row of brickwork even during the construction of the furnace.
Instead of a steel reinforced mesh, you can cover the stove with burlap, which must first be soaked in liquid diluted clay and a thin layer of clay mortar can be applied to the walls of the stove. The burlap is laid out and straightened on the surface of the oven so that no air gaps remain between them. This oven must not be overheated later on.

Plastering the stove with your own hands
We prepare a solution for do-it-yourself oven plaster
Furnaces are plastered with simple clay mortar or lime-gypsum, cement-clay-sand, lime-clay-sand mortar. You can purchase these solutions in the store dry, in bags, or you can make them yourself.
Since ancient times for do-it-yourself stove plaster clay mortar is popular. Plastering of the stove is done after the brickwork has completely hardened and its shrinkage is excluded (after about a month). If you properly prepare the solution and carry out the plastering of the oven, then the plaster will last for many years.
A high-quality solution for plastering the oven should be easily applied to its surface and smoothed well, the amount of sand mixed into the clay depends on the degree of fat content of the clay. If the fat content of the clay is high, then the proportion of the components of the plaster mixture should be 1/3, or 1/4. In order to increase the strength of the plaster, 0.1 / 0.2 shares of crushed fiberglass or asbestos fiber can be added to a clay-based mortar.

Now about how it should be right plaster the oven with your own hands.
Before starting work on plastering the stove, its surface must be cleaned of dust, remnants of masonry mortar and other contaminants. in order to improve the adhesion of the mortar to the brickwork, it is necessary to clear the joints between the bricks to a depth of about 0.5 cm. Before applying the plaster mortar, it is necessary to heat the stove and apply the mortar to the warm walls.

The proportions of the most common plastering compounds for plastering ovens

proportions in parts:

clay -1, sand - 2, asbestos - 0.1;

gypsum - 1, lime - 2, sand - 1, asbestos - 0.2

clay - 1, sand - 2, lime - 1, asbestos - 0.1;

clay - 1, sand - 2, cement - 1, asbestos - 0.1;

gypsum - 1, lime - 2, sand - 1, fiberglass - 0.2.

Plastering the oven
After preparing the plaster solution, we proceed to apply it to the surface, that is, to do-it-yourself oven plaster.
We start plastering the stove from the top. We moisten the brickwork with water and apply with a trowel or trowel, first a liquid layer of the solution, and then a thicker one. It is not recommended to apply layers thicker than 0.5 cm. In order for the plaster to dry evenly, it must be applied as evenly as possible. After the plaster has set, but is still soft, it is necessary to wipe it in a circular motion with a wooden float. At the end of this procedure, the surface of the oven should be smooth and even. If the plastered surface of the stove does not smooth out well, this indicates that the plaster has already set. In this case, after sprinkling with a large brush or a brush, moisten the gripped surface of the plaster and continue trowelling with a wooden brush. Ultimately, the thickness of the facing plaster layer should not be more than 1 cm.
The corners of the stove are plastered in the same way as door and plaster openings are plastered, with the help of wooden or metal slats, set in level. After applying the plaster mortar, after about 10-15 minutes, the rail is carefully removed and, if necessary, the angle is corrected and rubbed with a float.
After the plaster mortar has hardened, it is recommended to cover the oven with milk of lime, to which salt must be added (about 100 g per bucket). You can also dilute the lime dough removed by grouting with milk.

The process of plastering the oven with your own hands should subsequently have the following result:

• the deviation of the furnace surface, pushing off the vertical plane to the entire height, should not exceed more than 1 cm.
  
• Similarly horizontally - no more than 2mm.
  
• The deviation of the thrust between the corners from the straight line should not exceed 3mm.
  
• When a 2 m rule is applied, the detected differences in relation to a flat plane should not exceed 2 mm.
  

Do-it-yourself painting of the stove.
You can paint the stove as in the old fashioned way - with chalk on milk of lime, dyes for water-based paints are added for color. There are also many heat resistant enamels, paints and varnishes. Some paints have a peculiar smell when the oven is heated, but this will disappear over time. Emulsion, silicone, silicate paints with semi-matt and matt films are used for painting stoves and fireplaces.
Metal parts of the furnace, such as the furnace doors and the casing, are painted with paints of various colors on a silicon-organic basis (KO-84, KO-818, KO-822, KO-828, KO-5125, KO-174, KO-286, KO-198)
I will focus on one inexpensive, but rather beautiful and modern way of painting a plastered and unplastered stove - this is painting the stoves with water-based paints E-VA-27A E-VA-27APG, E-KCh-26, E-KCh-26A, E-KhV -28. For this, the plastered or unplastered surface of the furnace is cleaned of dust, primed with a universal primer, or a primer for mineral surfaces, after which a couple of layers of water-based paint are applied. The time interval between coats is written on the paint package. The paint can be given shades of the required colors with the help of coloring pigments (colors) for water-based paints.

The stove can be painted with several colors, or applied by hand or using a stencil. The only drawback of this paint is that it is not washable, but quickly renews itself if necessary with one new coat of paint. So that such a stove can later be easily wiped with a damp cloth, it is necessary to use washable water-based paint to paint the stove and apply drawings through a stencil, and after it has completely dried, open the painted surface of the stove with a heat-resistant matte or glossy water-based varnish. When using a glossy varnish, small irregularities will shine, so if there are any, it is better to use a matte varnish, then they will not be conspicuous.
Before applying the varnish, the water emulsion must be completely dry (the drying time is indicated on the package), otherwise it will be washed out when applying a heat-resistant water-based varnish.
The varnish will make the oven surface painted with washable water-based paints, more comfortable for cleaning and damp wiping of its surface.

You may be interested in reading how it is done decorative finishing stoves and fireplaces using the technology of thin-layer decorative printed (stamped) concrete. You can read about this by clicking on
This link

Cheap and angry* © All Rights Reserved. Materials are published solely for information and are protected
"The law on b intellectual property".
Copying is allowed only with reference to the source, otherwise copying is punishable by law.

Plastering a brick oven can significantly improve its appearance and increase its service life. In terms of the technique of execution, it differs little from other plastering works, but a number of specific nuances should be taken into account, especially in terms of the preparation of the solution. In general, such an event is quite accessible to any person, and can be carried out both using ready-made formulations and preparing a solution with your own hands.

Why is it recommended to plaster a brick oven? In terms of increasing the reliability of the entire structure, it should be noted that the plastered brick is protected from the direct impact of aggressive bath factors (temperature drops, moisture, steam). The brickwork itself increases the strength and tightness of the seams. The bonding material is less susceptible to cracking. 2 important reason is to improve the appearance. After plastering, the stove has an even surface of the walls, which gives it neatness and makes it possible to create a certain interior.

//www.youtube.com/watch?v=kXcpeiwD3dw

Brick kiln plaster has its own specific characteristics. First of all, this is due to the high temperature on the walls during its operation. The plastered layer must withstand the following influences: prolonged heating and open flame, temperature extremes, mechanical influences, smoke and steam, oil splashes during cooking. As the oven heats up, the brickwork tends to expand significantly, and therefore the plaster mortar for ovens must have increased elasticity in order to withstand such loads without cracking.

One of the functions of the stove is to heat the room. This condition dictates another requirement for stove plaster - good thermal conductivity. If additional substantial energy is required to heat this layer, then the efficiency of the entire structure will be significantly reduced. In addition, when heated, the material used for plaster should not emit substances harmful to the human body.

The choice of the composition of the plaster

The question of how to plaster the brick oven walls is the most important when planning such an event. It should be said right away that the usual cement-sand mortar used when plastering the walls of a building is not suitable for stoves. It will just crack in a very short time. For plaster, you can use a ready-made mixture designed specifically for this purpose, or prepare it yourself, but according to a special recipe.

To solve the question of how to plaster, simple 2-3-component mixtures and complex compositions with additives of various ingredients (fiberglass, asbestos, salts, plasticizers, etc.) can be used. The composition of the mortar also depends on the type of brick used for the construction of the furnaces (chamotte, red brick, silicate varieties, etc.). Certain components added to the plaster increase its adhesion to the material.

If a decision is made to use ready-made materials, then it is necessary to purchase an oven or fireplace plaster mixture. All have already been entered into it. necessary ingredients, and preparation for application consists in diluting with water in the proportion indicated in the instructions. When using them, one caveat should be taken into account: their long-term storage is undesirable, since atmospheric moisture can lead to premature hardening of the mixture in the form of poorly soluble lumps.

The most common types of homemade oven plaster solutions are:

• clay;
• lime-clay;
• calcareous-sandy-clayey,
• lime-gypsum;
• cement-sandy-clayey.

The practice of furnace construction shows that it is precisely such compositions that are least susceptible to cracking when heated. To improve the properties, other additives are also introduced.

When preparing the solution, it is important to choose the correct proportions of the ingredients. Precisely selected composition allows easy and even application of a thin layer on the oven wall. In particular, a certain consistency of the composition is used as a grout. The viscosity of the solution is regulated by the proportions of water, the plasticity largely depends on the amount of sand, and the more there is, the less elasticity of the mass.

Recipe selection

The specific formulation of the plaster solution depends on a number of these factors, and most often on the preferences of the performer himself, who determines the desired consistency by touch. The following standard mixtures can be distinguished (they are often used in the factory version as well):

1. Clay-sand mortar: clay (1 part) and sand (2 parts) with the addition of asbestos fiber (0.1 part).
2. Lime-clay composition: clay, lime and sand in a ratio of 1: 1: 2 with the introduction of asbestos (0.1 part).
3. Lime-gypsum mixture: lime, gypsum and sand in a ratio of 2: 1: 1 with asbestos (0.2 parts).
4. Cement-clay mortar: cement and clay (1 part each), sand (2 parts), asbestos fiber (0.1 part).

In such solutions, clay provides the plasticity of the composition, and asbestos is responsible for increased heat resistance. It should be noted that the fat content of the clay is considered an important parameter; with its high value, the sand content can be increased. In particular, when preparing a clay-sand mixture, 3-4 parts of sand can be added to 1 part of high-fat clay. If you want to increase the strength characteristics of plaster for stoves, you can add salt at the rate of 20 g per 1 liter of mortar.

The sequence of preparation of the plaster mortar is, in principle, standard. First, dry components are mixed, which are pre-sieved through a sieve to remove impurities and lumps. Clay or lime is separately mixed with water to obtain a homogeneous milk. The dry mixture is gradually introduced into the solution with thorough mixing. The result should be a creamy composition. Use the prepared solution as soon as possible. This condition especially applies to a mixture based on gypsum, which can thicken in 7-8 minutes, and after 30-40 minutes becomes unusable.

Since ancient times, it has been accepted to plaster the stove with clay mixed with sand, straw, sawdust and the addition of salt. Such a mixture effectively coped with the task and provided the required elasticity when heated.

Required tool

When carrying out work on plastering the furnace on your own, you should prepare the appropriate tool and containers for the solution in advance:

• trowel or plastering trowel;
• falcon;
• grater and half grater;
• rule;
• metal brush;
• brush or brush for wetting the surface;
• construction mixer;
• corner rail.

When preparing the solution, you will need a shovel, a scoop, a measuring container, a sieve, scales, a container for mixing ingredients. It is better to control the leveling of the surface with a building level. A chisel and a hammer can be useful to remove old plaster. A vacuum cleaner will help get rid of dust.

Process features

How to plaster a brick oven? The whole process can be divided into 3 stages: preparation of the surface of the oven walls, preparation of the solution and direct plastering. First of all, work should be carried out long before the active operation of the furnace, i.e. summer. If you plan to plaster a recently made, new brick oven, then you need to withstand a certain time until the masonry mortar is completely dry.

Preparatory activities are as follows:

• complete removal of old plaster and mechanical cleaning of the surface using a metal brush;
• dust and dirt removal;
• sanding the wall surface;
• deepening of the joints between the bricks for the plaster mortar to flow into them;
• final removal of dust using a vacuum cleaner, while it is not recommended to use a wet cloth, since dirt with water can seep into the material.

The next stage is the preparation of the solution, since it must be mixed immediately before application. To prepare the plaster mass, a container of the required volume is used, and the mixing itself is best done using a construction mixer.

How to plaster a stove? Usually the following order of work is maintained:

1. A reinforcing layer is laid on the surface of the furnace walls. Burlap has long been used for this purpose, but nowadays, metal or fiberglass mesh is preferred. As a rule, a mesh with a mesh of up to 1x1 cm is used. When using burlap, the fastening is done with clay, and the metal mesh is fixed with a wire with a diameter of 2-3 mm. The reinforcing layer must cover the entire furnace area.


2. Applying 1 layer with a solution of a more liquid consistency. The layer thickness is about 5 mm.
3. Application of 2 layers of a solution with the consistency of thick sour cream. Its thickness is 10-15 mm. It is better to start plastering from the top.
4. Plaster grouting and leveling. This operation is carried out in a circular motion with a cloth coated with a liquid solution.
5. Particular attention should be paid to the formation of the corners. For a perfectly straight edge, it is recommended to use a wooden batten.
6. If cracks form after complete drying of the plaster, then re-grout is carried out using a wet cloth.
7. The plastered stove can be whitewashed or any other heat-resistant, decorative coating can be applied.

A separate stage is the plastering of the chimney. It is especially important here to take into account the high degree of heating, while the plaster, on the contrary, should have certain thermal insulation properties. Even higher requirements are imposed on the plastering of the roof outlet pipe. On this element, the material is exposed to all external factors including moisture and sunlight, as well as exposure to fuel combustion products (smoke). Brickwork in such conditions must be reliably protected from these influences.

Plastering a brick oven will help increase its durability and add attractiveness. appearance... The process itself differs little from any other plastering work, but the composition for the furnace has its own specifics. Under these conditions, ordinary cement-sand mortar should not be used. The choice of the formulation of the plaster mixture is carried out taking into account special requirements in terms of long-term heat resistance.

//www.youtube.com/watch?v=SG3XatSH3eU