How to knead plaster on the oven. Mix for plastering the oven: the composition and proportions of the mortar for plastering with your own hands. What tools will be needed

It is advisable to process the furnaces after the brickwork has completely hardened and the possibility of its shrinkage has been excluded. As a rule, the masonry dries out in about 5-8 weeks.

Remember that plaster will last you a long time only if you prepare the mortar correctly. As a rule, they are plastered with an ordinary clay mixture. However, nowadays lime-gypsum mortars have gained wide popularity.

You can also use a cement-clay-sand or lime-clay-sand composition. You can easily purchase all these materials at any hardware store in the form of a dry mix or cook it yourself.

A quality stucco mixture should be easy to apply and easy to smooth on the surface. The amount of sand that needs to be mixed into the clay solution depends on the degree of fat content of your mixture.

If you are using oily clay, then the ratio of the main components in the resulting mixture should be approximately 1:3-1:4. To increase the density of clay-based plaster, you can add about 0.1-0.2 shares of crushed fiberglass or asbestos.

How is the process

We figured out what solution to treat the surface so that the finish does not crack. Now let's look at how to apply plaster correctly.

Before you begin plastering your fireplace, you should thoroughly clean the surface of dust, mortar residue, and other debris.

It is advisable to heat the stove before plastering and apply the solution to warm walls.

To improve adhesion to the masonry, you should clear all the seams between the laid bricks to a depth of approximately 0.5-1 cm.
Plastering the oven must begin from the top.
It is advisable to thoroughly moisten the brickwork with water.
Then, using a special float or trowel, apply a liquid layer of the solution.
After it dries a little, you can start applying a thick layer.
In order for the plaster to dry evenly, try to apply it in an even layer.
After it has set sufficiently, but is slightly soft, rub it with a wooden grater.

Advice: It is not rational to apply a layer with a thickness of more than 0.5-0.7 cm.

After you complete these operations, the surface of your fireplace or stove should be smooth and perfectly even. If you notice that the surface layer is not smoothed out well, then the plaster has not had time to set.

If this is the case, you need to moisten the set part of the plaster with a brush. Then you can continue finishing work with a wooden brush.

The thickness of the facing layer of plaster should not exceed 1 cm.

Use wooden or metal slats to finish the corners. Be sure to level them. After plastering the corners, remove the slats after 10-20 minutes. If necessary, correct the corner with a grater.

After you finish plastering the stove, you need to cover the surface with lime milk. Be sure to add salt to the composition of the milk.

The applied layer falls off the stove or fireplace for the following reasons:

Incorrect ligation of a row of bricks.
Too narrow or wide seam.
Severe overheating.

Advice: to prevent these problems, experts advise using a reinforcing mesh during the plastering process, in which the cells will not exceed 1-1.5 cm.

The mesh must be installed with wire on the brickwork. The thickness of the wire should be about 3 mm. It is advisable to start it in each row of masonry before you start building a fireplace.

If you do not have the opportunity to use reinforced mesh, you can take burlap. First, it must be soaked in liquid clay, and the fireplace wall should be coated with clay mortar.

Remember that the burlap on the stove must be installed in such a way as to completely exclude air gaps between it and the stove itself.

It is worth noting! The stove, covered with burlap, should not be overheated.

If after plastering you find a crack, then you need to prepare a special solution. To seal cracks, craftsmen recommend using a refractory mixture.

Such plaster for the oven is a conventional ready-made mixture using refractory clay, lime, cement:

Be sure to sift all components through a sieve.
Soak the clay overnight.
Later, extinguish the lime with water.

Remember that your clay mortar should be uniform and thick.

The mixture with the use of cement is usable for only an hour.

Before using this solution, it must be diluted with water. Then add PVA glue and you can start plastering the pipe and the rest of the surface.

After receiving the solution, clean the cracks well. It is advisable to moisten them with warm water. Then cover the surface of the stove with a metal mesh and nail it. It is advisable to nail the mesh in a checkerboard pattern at a distance of 10-12 cm.

As noted above, the putty of cracks must be done only on a heated stove. This is done so that the seams expand and provide good adhesion to the plaster. During heating, the pores of the brick will open up and will be in effective contact with the mixture.

If, after drying the plaster, you find new cracks, then trim their edges and moisten with warm water. Then rub with a thick solution.

After all layers are completely dry, it is desirable to whitewash the surface of the stove. It is better to use paints based on chalk or lime. It is highly not recommended to use oil formulations, as they begin to disintegrate during the heating process and smell unpleasant.

Gas or central heating has come to almost every home today, but despite this, wood stoves do not lose their popularity. This is due to many factors, here is the environmental friendliness of the fuel, and in some way savings, especially when it comes to bringing gas distribution to a site remote from the main line.

But, despite all the popularity, many are still wondering how to plaster a brick stove so that the coating does not start to crumble after a few years. In fact, there is nothing complicated here, and in this article we will try to prove this statement.

Talk about the fact that plastering a brick oven is a complex process that only professionals can do is nothing more than a bike. In fact, it is quite possible to do it yourself, even if there was no such experience before.

So:

Like any repair or finishing work, plastering should begin with the preparation of the furnace and its surface. This is especially important if the stove has been built recently and this is its first finish. In this case, thorough drying is necessary. Under natural conditions, it can last several months, so you can speed up the process and lightly melt the oven.
You only need to do this for a few hours a day, and in a week the surface will be completely ready for work.

Important! In addition to drying the masonry, the oven must go through a natural shrinkage stage, otherwise the plaster may begin to crack, regardless of the quality of the work done.

In order for the coating to turn out even and without drops, before plastering the brick oven, beacons must be fixed on it, as shown in the photo at the beginning of this article. They serve to ensure that the tool with which the mixture will be applied does not push through the surface more than it should.
The beacons themselves are made of metal, so they are not afraid of even very high temperatures. But more on that later.

We prepare the solution

So:

Progress, which does not stand still, has reached the stoves, today you can buy a ready-made mixture, which comes with detailed instructions for applying it. But supporters of classical plaster try to prepare the mortar on their own. Whether this makes sense is unknown, since the price will differ slightly, but we will still describe several options.

Advice! before buying a ready-made mixture, you should definitely find out its composition and the maximum temperature that it can withstand.

Just a few, because there is a difference between how to plaster a brick pipe and how to plaster the stove itself. It consists in the temperature difference between the "body" and the chimney, and in addition, there are special mixtures for plastering pipes located outside the room. But first things first.

Plaster mixes

So:

It is customary to use asbestos in the form of small fibers as additional additives, it does not burn and retains the temperature well, but in recent years more and more controversy has flared up around this material. Some say that it is extremely unhealthy, others deny it.
In any case, we will not advise adding it to the brick oven plaster mix, and leave this question to the discretion of everyone.
To prepare the solution, it is enough to mix all the ingredients in one container and dilute them with water to the desired consistency. Most importantly, do not forget that lime must be slaked, and how to do it correctly is shown in the video in this article.

Plastering the oven

Having chosen how to plaster a brick oven, you can go directly to work.

It happens in several stages:

We heat the stove and let it cool to room temperature, but do not allow it to cool until the masonry begins to absorb new moisture.
Thoroughly clean the dried surface with a brush or broom. The main thing is to remove all the dust and not let it lie back down again.
We dilute the clay in a separate bucket to a liquid state and apply the mixture to the surface with a thick brush. This will wet the oven under the primary layer and create additional adhesion for the plaster.

Now we fix the beacons. This can be done on the same plaster solution, which will securely fix them on the surface.
The next stage is the fastening of the reinforcing mesh. It can be made of metal or heat-resistant fiberglass, the main thing is that the mesh size does not exceed 2 cm. Previously, burlap was used as reinforcement, which was glued to the stove and covered with plaster, but such protection has more minuses than pluses, which means there is no point in sacrificing quality for the sake of tradition.

Next, we apply the first layer of plaster, which should cover the reinforcing mesh, but not reach the level of the lighthouses. Now he needs to be allowed to dry well, but without melting the oven.

When the first layer is dry, apply the topcoat, focusing on the beacons. The two layers will adhere securely to each other, and after one more drying, the surface can be sanded with fine sandpaper.

When the plaster coating is leveled, the stove can be painted.

Conclusion

We hope that we have succeeded in debunking the myth about the complexity of oven plastering. As you can see, this process, although time-consuming, is completely simple.

By the way, often stoves are not plastered at all, and the brick itself acts as a decorative finish, with even and neat masonry. A lot also depends on the location. But wherever there is a brick oven, the plastered version not only looks better, but also keeps heat much better.

How to plaster the oven so that it does not crack during everyday use? This question arises for those homeowners who have just acquired this heating device, and in those cases when it is time to repair a long-built stove.

It should be noted that cracking most often occurs when violations are made in the technology of the plastering process or in preparing the surface for applying the finish, as well as due to improper preparation of the solution.

For plastering the brick walls of the furnace, traditional sand-clay mortars and professionally prepared plaster mixes are used, which can be bought today at any hardware or specialized store.

But whatever type of plaster is chosen, it must meet certain requirements, such as heat resistance, high adhesion and an adequate response to the expansion of the wall material when heated.

Why plaster the oven at all?

In what cases and why are ovens plastered? The answer to this question is no less important than the first, because, having learned it, you can understand whether it is worth carrying out this process at all, or you can leave the stove unfinished, or decorate its walls with ceramic or fireclay tiles.

The reasons that require finishing the walls with plaster include:

If the stove is old and had already been plastered before, but for some reason the finish cracked and began to fall off, and sloppy masonry was found under it.
If the stove is old and there is a risk of cracking the masonry mortar in the joints and the penetration of carbon monoxide into the room.
If there is a need to transform this structure, give it neatness and aesthetics, for example, when updating the entire interior and changing the style of its design.
Over time, various insects can settle in the seams between rows of bricks, especially in cases where the laying was carried out on natural materials. Timely processing and plastering will help prevent their occurrence.
If the stove has just been erected, but the masonry is done carelessly, without jointing, and the structure does not look aesthetically pleasing, it is plaster that will help correct this situation.

The advantage of plaster over other finishing materials:

It should be noted that plastering the stove is the most affordable and easiest way to tidy up the stove surfaces.
By choosing plaster for wall decoration, you can save a lot, since the price of ceramic tiles or stove tiles is several orders of magnitude higher than that of a plaster mixture.
Plastering can be applied to any of the existing types of stoves, both for the restoration of an old stove and for finishing a newly built one.
The plaster increases the thickness of the wall, which increases the heat capacity of the building and leads to fuel savings, since the furnace cools down longer.
Plaster increases the level of fire safety and reduces the possibility of carbon monoxide penetration into the room.
The plastered surface can be covered with water-based paint, whitewash or decorative plasters.

Tools to get the job done

The quality of plaster application and its ideal distribution on the surface of the oven walls directly affects the adhesion of materials and longevity operation. In order for the plastering process to be easy and bring the expected result, it is necessary to carry it out with high-quality tools, which include:

Spatulas - from medium for taking the solution from the tank, to wide, used for applying it to the wall.
A plastering hammer used for hammering plaster nails.
Trowel (trowel) for applying and distributing the mortar on the oven walls.
Cam hammer used to work with a chisel, trojan and gear.
Scissors for cutting fiberglass mesh. If the walls are covered with a chain-link mesh, then metal scissors will also be required.
Grater and half grater. These tools are used to level and smooth plastered surfaces.
The trowel is used to bring the surface to perfect smoothness.
Chisel. With this tool, notches are made on the surface of the furnace walls for better adhesion of materials.
Brushes of different sizes for applying soil compositions, and when using some techniques, both the plaster itself and to give it a textured surface, if it is provided.
Brush with metal bristles - for cleaning surfaces and seams, when removing old plaster.
Building level to check the verticality and horizontal planes.
A plumb line is used to control the evenness of walls and applied plaster.
The rule helps to align the plaster applied to the walls with the beacons installed on them.

Types of plaster solutions

As you know, the oven is subjected to constant temperature changes, so the plaster layer must be resistant to this phenomenon. When composing a solution on your own and choosing the proportions of materials, you must take this into account.

The most important point is the composition of the plaster mortar

Plaster mixtures are simple and complex:

Simple are called compositions consisting of two ingredients - clay and sand.
Complex solutions are those that have more than two components in their composition.

Some of the materials before making the mixture must be prepared by cleaning them from various impurities:

Sand should be sifted through a fine sieve.
Clay is also rubbed through a fine metal mesh, turning it into powder and freeing it from plant roots and small stones.

Clay for the preparation of the plaster mix is chosen to be quite oily, since this quality will directly affect the adhesion of the plaster and the wall. In the event that excessive fat content of clay is noticeable, a little more sand can be added to the solution.

Clay before kneading the solution is soaked, mixing with water. Further, it is left for several hours. If during this time it has absorbed all the water, then the liquid is added more, and so on until the water covers the clay from above by 100 ÷ 150 mm. After that, the mixture is mixed - it should have the consistency of thick sour cream and have good plasticity.

Prices for heat-resistant plaster

plaster for stoves and fireplaces

Video: Tips for Properly Soaking Clay for Mortar

Asbestos, which is added to the solution, plays the role of a reinforcing component. Instead of asbestos, hemp, finely chopped straw or crushed glass fiber (microfiber) can be used.

It should be noted that for plaster compositions it is better to choose natural, environmentally friendly materials that, when heated, will not emit harmful fumes that are unsafe for the health of residents of the house.

Some masters add salt to the solution and this is explained by the fact that it makes the solution stronger. However, this is not quite true. Salt does not strengthen the clay, but increases its hygroscopicity, which makes it more ductile, preventing it from drying out, so the plaster will crack less. In addition, various insects do not start up in salt plaster, which is also very important for a private house.

The table below shows several formulations of plaster mortars for furnaces.

Composition Number	Clay	Sand	fluffed asbestos	Lime	Cement	Gypsum
1	1	2	0.1	-	-	-
2	1	2	0.1	1	-	-
3	1	2	0.1	-	1	-
4	1	1	0.2	2	-	1
5	1	1	0.2	2	-	-
6	-	1	0.1	2	-	1

Separately, it must be said about such material as gypsum, which is one of the components of some plaster solutions. For example, in mix #4, it is used instead of cement as a bonding agent. Gypsum hardens very quickly, its setting occurs almost immediately after application to the wall, and after 10 ÷ 15 minutes the plaster layer with its use will already harden.

This building material is often used together with lime, as it gives the mortar strength and promotes rapid drying. But, choosing a solution with the addition of gypsum, you need to take into account its properties and prepare small portions of the mixture, otherwise it will harden and be unsuitable for work. It will definitely not be possible to extend its “life” even for a short time by diluting it with water.

We plaster the oven with our own hands

Preparatory work

Plastering will not turn out to be of high quality if the surface of the furnace walls is not well prepared for the application of the finishing material. Therefore, the first step is preparatory work, which will create good conditions for the adhesion of the plaster.

If an old stove or fireplace is to be put in order, then its surface must be freed from the plaster on it, knocking it down manually with a chisel and a hammer. After the walls are freed from the old layer, they are well cleaned of dust - this process is carried out with an iron and ordinary brush.
The fresh masonry of the furnace must also be cleaned, as the remains of the masonry material may linger on the bricks, which will reduce adhesion, which will lead to the plaster lagging behind the wall.
Next, there is a deepening of the seams, and this is carried out both for the new stove and for the restored one. Dry mortar from the joints is selected by 5 ÷ 10 mm. Then the seams are well cleaned of dust.
After cleaning, the walls are well primed, and it is necessary to cover deep seams with a primer with a thin brush.

Sometimes it is necessary to apply several layers of plaster - such a need arises if the walls of the furnace are very uneven. This method of plastering requires additional strengthening of the surface with a metal or fiberglass mesh with cells of 15 ÷ 20 mm. Reinforcement will fix the plaster well on the walls, making it less vulnerable to temperature changes. In addition, a thicker layer will increase the heat capacity of the furnace. The metal mesh is attached to the surface with wide-headed nails driven into the seams between the bricks.

Fiberglass mesh embedded in on theworn on the wall of the mixture, or the solution is applied to the grid from above, leveling it. Fiberglass is mainly used if the surface is fairly even.

To maintain or restore the evenness of the corners of the furnace, steel or perforated aluminum corners are mounted on the adhesive mass.

In order to achieve evenness of the wall with large differences, beacons made of metal profiles are placed on top of the reinforcing mesh, fixed on the surface with a gypsum mixture that dries quickly, which practically does not slow down the work. If time suffers, then the beacons can also be set on a clay solution. But such a method is possible if the mesh is close to the wall.

The walls of the furnace can be leveled to perfect smoothness for whitewashing or painting, or you can leave the surface even, but rough, to cover it with decorative embossed plaster. It should be noted that under the laying of ceramic tiles or decorative plaster it is recommended to apply a not too thick preparatory finishing layer.

There are various ready-made compounds or additives that help to imitate natural stone of different breeds. The surface of the furnace in this case, with the correct preparation of the solution, will be impossible to distinguish from natural material.

The table shows the recipe for the preparation of decorative plaster solutions.

Component composition of decorative plasters imitating the texture of natural stone, in parts by volume
Material	white marble	yellow marble	Red marble	Gray granite	labradorite
Portland cement M400	1	1	1	1	1
lime dough	0.2	0.15	0.1	0.1	-
marble flour	0.1	0.05	0.1	0.1	-
Marble chips up to 6 mm in size	3	3	3	3	3
Mica (from cement volume)	0.1	0.1	0.1	0.1	0.1
Paint (from cement volume), %	-	Ocher 3 ÷ 5	Minium iron 5÷10	Manganese peroxide 1÷5	Manganese peroxide 6÷8

Preparing the plaster mixture

The solution, composed in the correct proportion and well mixed, is one of the factors on which the quality plastering of the furnace depends. To mix the mixture, you will need a drill and a mixer nozzle.

Before starting cooking, you need to consider some points:

Soaked clay, if it is used in a solution, should swell for at least two to three days. If, after standing this time, it continues to absorb water, then it is not ready for kneading and should be added to it with more water and left to swell for a while.
The sand added to the solution must not only be sifted, but also dried - this will help in maintaining the correct proportions when composing the mixture.
Lime will be a good plasticizer for the solution - its viscosity will make the mixture more adhesive. In addition, it will help the solution to set quickly enough, which will shorten the period of work. In principle, a small amount of it is recommended to be added to mixtures consisting of any ingredients.
The most suitable of the brands of cement is M400. It begins to solidify in 17 ÷ 20 minutes after kneading, sets after 3.5 ÷ 4 hours, and its final solidification and strength development occurs after two to three days.

If you purchase a ready-made dry mix, then it is not difficult to prepare it:

Water is poured into a clean container of a suitable size.
Then powder is poured into the container, the proportions of which in relation to water are indicated on the package.
The solution is mixed with a mixer until a homogeneous mass is formed without lumps and dry patches.
The solution is kept for 7 ÷ 10 minutes, then mixed again, and after that it is ready for use.

If for plastering the solution will be prepared independently, using traditional materials, then the process is carried out as follows:

The required amount of clay mass is laid out in the container. Dry sand, slaked lime and cement are added to it in accordance with the indicated proportions.
The mixture is also stirred with a mixer until smooth. If necessary, a small amount of water is added to the solution during the mixing process.

This solution is applied immediately, as cement with lime sets quickly enough.

Plastering process

As mentioned above, the plastering process can take place in different ways, some of which will be discussed below.

First way

This method is used if there are large distortions on the surface, and it requires cardinal alignment by applying a layer with a thickness of 50 to 80 mm.

In this variant, leveling beacons are fixed first. They are set according to the building level, achieving perfect evenness.

After that, the oven is heated to a warm state.
Further, the entire surface of the furnace is wetted with water using a wide brush or roller. Water will nail dust particles and dry mortar into the joints.
After that, the walls are primed. The primer coat must dry, creating a layer that will promote adhesion of the surface and applied materials.

A sketch of the solution, or "spray"

Further, by "spraying" (sketching), the first plaster layer is applied, which should not be thicker than 4 ÷ 5 mm. The solution for this layer should have the consistency of medium liquid sour cream. The mixture is applied with accentuated movements, since the mortar must fall into the seams between the masonry rows. After completing the outline, the mortar is allowed to dry well.
After it dries, the next layer is applied, which should protrude above the installed beacons by 8 ÷ 10 mm. The solution is applied from the bottom of the wall, approximately 400 ÷ 500 mm, and immediately leveled by the rule that is led along the lighthouses. Next, the mortar is poured onto the next section and leveled again, and so on until the entire surface is covered with a leveling plaster layer.

While the mixture is still wet, the grout is gently passed over it, grinding the surface.

The stove-makers have one secret that contributes to the uniform drying of the plaster layer, which reduces the risk of cracks appearing on its surface. The whole oven, after applying a solution to it and grinding, is covered with a damp burlap. If it dries quickly, it is moistened one more ÷ two times.

When the surface dries, the matting is removed, and if cracks are found, they are immediately overwritten and smoothed with a rubber-surfaced trowel.

The third layer - “covering”, is smoothing, so the solution for it is made quite liquid and applied with a thickness of only 1.5 ÷ 2 mm. This layer is applied if the surface of the furnace will be covered with paint or whitewash.
Difficulty always arises when deriving corners, even if they are reinforced with metal corners. The easiest way to apply mortar evenly and level them well is to use an angled spatula.

Prices for corner spatulas

angle spatula

Some craftsmen use the fastening of a wooden rail on one side to remove the corner, and after the applied solution dries, the rail is transferred to the other side of the corner, and the mixture is applied to the one where the guide was installed earlier.

It is recommended to round the very edge of the corner, which can be achieved using an angled spatula. This must be done, first of all, for the safety of small children living in the house. Also, the rounded corner is less prone to chipping, for example, during the period of repair and movement of furniture.

Second way

When using this method of bringing the furnace in order, a metal chain-link mesh is used, which reinforces the surface of the furnace and sets the thickness of the plaster coating.

With a metal mesh and level the surface, moving it away from the wall in the right places at a distance of up to 25 mm. For rigidity, a wire is placed under it, which can be hooked onto the mesh itself or metal slats.

In this method, the plaster mixture is also applied in several layers until the mesh is completely covered under it.

Finishing with the use of such reinforcement is more durable and securely fixed to the surface.

The first layer is also applied by the "spray" method - the solution must pass through the mesh and be well fixed on the wall. Having sprayed this surface, the walls are left to dry. After they dry, the grid will become motionless, and it will be easy to apply the next, already leveling layers of the solution on it.
After leveling and drying of the upper, last layer, the resulting cracks are smeared and overwritten.
The next step is the installation of a decorative coating.

Third way

The third method of plastering is used if the walls of the furnace are fairly even, and they only need to be “refreshed” a little.

The solution for this method is applied in one or two layers with a thickness of not more than 2 ÷ 3 mm.

The wall is also prepared and primed.
Then, if necessary, thin metal guide rails, which will help you navigate the thickness of the layer. Reiki may not be used if the surface is flat and not needed.
With this method of finishing, it is best to use a solution with the addition of fireclay clay and crushed asbestos, which will play the role of a reinforcing component.
The mixture is applied, starting from the bottom of the oven, with a wide spatula, and immediately leveled with a rule over metal slats. If beacons are not used, then the solution is smoothed, focusing only on the evenness of the surface.
The corners are removed in this case also with the help of an angled spatula.
When the walls of the furnace are completely covered with mortar, they are carefully, without pressure, leveled cleanly with grout.

It is good to lay ceramic or fireclay tiles on such a finish, as well as apply decorative embossed plaster.

Furnace decoration

Decorative finishing of the furnace can be made for every taste. If the plaster turned out to be even, then bake can be covered with whitewash - this method can be called traditional, as it has been used for a long time. The whitewash was often painted with water-based paints, which gave the room an originality and emphasized national traditions. Most often, ornaments were chosen that are characteristic of the area where the building is located.

Today, with the advent of new technologies and materials, the stove is often decorated with plasters that can create patterns on the surface that imitate one of the types of stone or a uniform relief structure.

There are other elements of three-dimensional drawings - in this case, everything will depend on the imagination of the master. To create them, improvised objects are often used, for example, plastic wrap, brush, brush, dish cleaning net and other materials or accessories.

If there is a predisposition to creativity, you can create relief compositions from decorative plaster that protrude beyond the walls of the furnace even by 7 ÷ 10 mm, and then cover them with coloring compositions. The application of paints takes place on wet decorative plaster - then they are well absorbed into its surface and become more durable. After the entire surface has dried, painting can be done one more time.

In addition to decorative plaster, the stove is often decorated with terracotta or ceramic tiles. The presence of corner trim elements on sale greatly simplifies its installation and makes it possible to make corners and all surfaces neat and aesthetic. The tile is mounted on a special cement-based adhesive, which has the ability to withstand the effects of temperature extremes.

Video: plastering the oven followed by terracotta tiles

What should be considered when starting plastering and finishing?

When carrying out plastering of the furnace, you need to take into account some points that may affect the quality of the work performed.

It is impossible to apply plaster on a newly erected furnace structure. A "fresh" stove should not only be well dried, but also go through the stages of shrinkage. To do this, it is operated for two to three months, and only after this period, you can start finishing work.

Only water-based paints can be used to paint the plastered surface. Other coloring compositions containing drying oil or organic solvents will emit harmful substances and unpleasant odors into the living quarters when the furnace is fired.

For all work on plastering and decorating the stove, it is recommended to use materials on a natural basis, without any synthetic additives that are unfavorable to human health.

It should be noted that all the methods discussed in the article are not as easy to perform as it seems at first glance. Therefore, with a complete lack of experience in this work, you should not take risks and translate enough, sometimes expensive materials. It is better to entrust these important events to real professionals who know firsthand the secrets of laying and subsequent finishing of the furnace.

Evgeny AfanasievChief Editor

Publication author 28.08.2015

Despite the huge number of modern heating systems, in many country houses a brick oven has been the only household heating appliance for many years, which serves both for heating the home and for cooking.

To ensure uniform heating of the room, it is usually installed in the central part of a residential building. And to maintain the proper appearance and increase the heat capacity of the kiln brick surface using a variety of materials.

Self-finishing a brick oven

This article will talk about covering a brick oven with a layer of plaster, followed by whitewashing or painting the treated surface. Here, instructions will be given, which will describe how to plaster the oven: so that it does not crack - what materials are better to use for this. In addition, the reader will be able to get some advice and guidance regarding the issue.

Benefits of plaster finish

Do-it-yourself plastering is the easiest and most affordable way of outdoor decoration. And, in addition, taking into account the high cost of high-quality ceramic tiles or stove tiles, the rather low price of the components of the plaster makes this type of finish also the most inexpensive.

Thus, the following advantages of finishing the furnace with a plaster mixture can be distinguished:

An inexpensive and affordable way that can be done even without the skills of plastering.
Can be applied to all kinds of brick kilns, while it can be used for both
new, and for the restoration of the old furnace.
It does not require major alterations or changes in the design.
Due to the solution used, the wall thickness and the total mass of the furnace increase, which leads to an increase in its heat capacity, fuel economy and an increase in fire safety.
Whitewashing or painting the surface with water-based interior paints can be used as a decorative coating.

Many owners of private houses are concerned about the question: why does the plaster on the stove crack? Most often this happens due to non-compliance with the rules and technology of surface preparation, the manufacture of a building mixture or the application of a plaster solution during work.

Where to begin

First of all, you need to understand that any furnace work, including exterior decoration, should be carried out in the warm season long before the onset of the heating season. If the construction of the brick kiln was built recently, it is necessary to let it stand for several days to completely dry the masonry mortar.

Before plastering the oven - so that the plaster does not crack and fall off, it is necessary to perform simple preparatory work.

Prepare the workspace, as well as cover the floor and furniture in the room with a protective plastic film.
Remove old loose plaster and carefully work the surface with a hard brush with metal bristles.
Using a vacuum cleaner and a dry cloth or a wide brush, clean the surface of debris and dust.
Consistently process the outer side of the bricks with coarse-grained emery cloth, and then again carefully remove the resulting dust.

When finishing a newly built furnace, it is necessary to grout the outer surface of the brickwork using a clay mortar or a mixture of cement with crushed asbestos, and then leave it for several days until completely dry.

Advice! When cleaning the surface of a brick from dust, a wet cloth should not be used, as this will lead to the formation and absorption of liquid dirt, which can be difficult to remove.

Solution preparation

Answering the question: how to plaster the oven - so that the surface does not crack later, we can recommend two types of finishing mixtures, which will be discussed further.

For plastering brick surfaces that are exposed to high temperatures, a special dry mortar is sold, which is called: plaster for stoves and fireplaces.

It is easy to prepare right at the workplace in the required quantity.

Pour about one quarter of the water into a clean container of a suitable volume.
Pour the required amount of dry mortar into the water, observing the proportions in strict accordance with the instructions.
Using an electric mixer or a special nozzle on a drill, mix the solution thoroughly until a homogeneous mass is obtained, avoiding the formation of hard lumps.
Keep the resulting mixture for 5-10 minutes, and mix thoroughly before use.

Another plaster composition, which has been used for many years for finishing stoves and fireplaces, can be prepared on the basis of pure natural clay without impurities.

Pour one volume part of clay into a wide container, add water and knead to a liquid dough.
In the resulting base, add one volume part of clean dry sand, building cement and slaked lime.
Stir the whole mixture thoroughly by hand or using a construction mixer until smooth. If necessary, water can be added during the mixing process, but care must be taken not to make the solution too thin.

Applying plaster

The process of plastering a stove is not much different from applying a leveling mortar to any other wall surfaces, however, some features should be taken into account when performing it.

Before starting work, it is necessary to heat the furnace several times for several hours to fire and shrink the masonry mortar.
Over the entire area of the brickwork, it is necessary to fix a fine-mesh reinforcing mesh made of galvanized metal or fiberglass.
Immediately before applying the mixture, evenly moisten the walls with a very thin solution of clay in water.
To apply the plaster mortar, use a construction trowel or a wide spatula.
The thickness of each layer should not exceed 15 mm, while the thickness of the first layer is recommended to be no more than 5 mm.
Drying of the solution should occur naturally. To do this, it is impossible to prevent the formation of drafts in the room and the use of heating devices.
The first heating can be performed only after the plaster layer has completely dried, however, it should be remembered that this may take up to 30 days.

After drying, small cracks may appear. To eliminate them, it is necessary to moisten the surface with water and grout with a small amount of plaster mixture. After drying, the stove can be whitewashed or painted with water-based paint in any suitable color.

Advice! With a small thickness of the leveling layer, ordinary clean burlap can be used as a reinforcing mesh.

Conclusion

As can be seen from the materials of this article, finishing the oven with plaster is not very difficult and, if desired, can be done by a home craftsman without outside help. For more information on this subject, see the video in this article.

With the advent of the era of total gasification, traditional stoves began to be perceived by us as a relic of the past. There were practically no special innovations in finishing, but in vain! The stove is a reliable source of heat that does not suffer from power outages and energy prices (gas, diesel fuel, pellets). Today there has been a reassessment of values, the services of stove-makers are again in demand, the almost forgotten secrets of stove finishing are being restored. If you decide to tidy up an old stove or plaster a new one, the question of the correct selection of a building mixture is inevitable, because the requirements for finishing materials are quite high - the plaster will heat up many times afterwards. It is important that the base is environmentally friendly - when heated, various toxic compounds can be released, which is unacceptable, in addition, the plaster must have elasticity and good thermal conductivity. Let's consider various options for the composition of the plaster, so that the question "how to plaster the oven" finds the only correct answer.

Firstly, plaster gives the stove a neat appearance, decorates the interior of the room. Secondly, plastering enhances the strength and tightness of the stove masonry. Indeed, over time, due to temperature changes in the masonry, cracks form through which smoke can penetrate into the room, which negatively affects not only the interior (smoky walls, curtains and furniture), but most importantly, it is dangerous to health.

The cost of numerous heat-resistant materials presented on the shelves of building supermarkets is much higher than the traditional clay-based mixtures for plastering ovens. You can plaster the oven with a clay-sand mortar with the addition of cement or lime, or with a lime-gypsum mortar. More often than others, clay-based solutions are used. Plastering brickwork is possible only after it has completely hardened to prevent shrinkage (about a month later). The percentage of components in the clay-sand solution is not the same. It all depends on the fat content of the clay. If the fat content is high, 4 parts of sand will be needed for 1 part of clay. In order to increase the strength of the plaster, additional components are often added to the solution: fiberglass or asbestos.

How to plaster an oven

Furnace prepared for plastering: defects are repaired, the surface is cleaned, the seams between the bricks are embroidered

Prepare by the rules

First of all, you should properly prepare the surface: clean it from dirt, dust, remnants of the old mortar. In order to improve the adhesion of the mortar to the brickwork, additional cleaning of the joints to a depth of 5 to 10 mm is recommended. It is recommended to hammer nails (40-50 mm long) into the seams in increments of no more than 15 cm, so that they protrude outward by about a quarter of the length. It is advisable to treat the surface with a primer specially designed for such purposes. In order to create additional roughness (for the strength of the connection), a fiberglass mesh should be used. It is attached to the masonry using a liquid layer of mortar. Only hot walls are plastered.

The plastering of the oven is carried out in stages, usually several layers of mortar are applied, each of which is given time to dry completely.

Solution application process

The solution is applied in stages (in layers). Before applying the plaster, be sure to moisten the masonry with water. The first layer of plaster must be made liquid, creamy consistency. After the first layer has hardened, a second layer can be applied, up to 1 cm thick, after the second layer has set, you can begin to level the surface. After the mortar has set a little, you can rub the surface. Before grouting, you need to moisten the plaster with water, then wipe all the irregularities with a grater in a circular motion. If cracks are visible after drying, they should be expanded, moistened with water, filled with mortar and, after drying, rubbed.

What plaster is better to use

There are special requirements for oven plaster. The composition of the building mix for plastering the oven differs significantly from the usual cement-sand mortars for plastering the walls of houses. This is due to the fact that the masonry of the furnace, when heated, has the ability to expand and for a reliable connection it is extremely important that the plaster is elastic. In addition, in order for the stove to warm up the room well and quickly, oven plaster must have good thermal conductivity. In order to impart such properties, various components are added to the composition of the solutions: clay, fireclay, asbestos, fiberglass, salt. Both simple clay and complex solutions are used, which you can prepare yourself or buy ready-made mixtures in the store. Examples of common mixture compositions are considered in Table 1.

Table 1. The composition of mortar mixtures for plastering the oven

Depending on the fat content of the clay, the ratio of the components of the solution may vary. The fatter the clay, the more sand will be required. The order of mixing the solutions is approximately the same - first of all, dry components are mixed, adding the mixture to a solution of lime or clay. For additional strength, 200 g of salt can be added to a bucket of clay-sand mortar

Consider the recipes for commonly used plaster compositions: part of the clay, part of the lime test, one tenth of the asbestos and two parts of the sand are laid at the same time. The mixture should be thoroughly mixed, and, gradually adding water, bring to the desired consistency.

Another recipe for durable plaster (the only drawback of the mixture is the need for quick use, because an hour after preparation the mixture will be unusable): for two parts of sand, you need to take one part of clay and cement (grade 400 or 500). First, you need to knead a thick dough from water, clay and sand, then add cement and asbestos to the composition, add water and mix thoroughly. The density of the solution should be creamy consistency.

Any composition necessarily includes a binder aggregate and water. The binder may be a single component or a mixture (eg cement and lime). If you decide to use a high-strength gypsum-based mixture, consider an important feature: the mixture sets very quickly (within 6 minutes). After half an hour, this mixture is no longer suitable for use.

Video: preparing a solution of sand and clay

Having chosen one of the above recipes for the composition of the mixture for plaster, or using a purchased mixture, monitor the quality of the preparation of the solution. A properly prepared mortar should be easily and evenly applied to the masonry, and there should not be any problems with smoothing. It is important to observe the proportions - we regulate the viscosity by adding water, we do not exceed the norm of sand - the plasticity of the solution will suffer.