How to make plaster with clay: the composition of the mixture and application features. Features, rules for the manufacture and application of clay plaster How to coat a wooden house with clay

Until recently, clay houses were considered housing for the poor. It was related to minimal cost for its construction.

Clay roofing for a house

Clay like construction material used in housing construction for a long time. Today, history can confirm that not only houses for poor people were built from clay. Almost all over the world there are examples of how clay perfectly coped with the functions assigned to it, not only in the economical construction of housing, but also in the construction of monumental buildings.

Houses were rarely built purely from clay, this was due to the fact that it had a rather fragile structure after complete drying. Therefore, it was necessary to look for reinforcing materials. This turned out to be the easiest. Natural materials such as:

Straw;
Small twigs of trees;
Reeds;
Bamboo;
And similar materials.

They were the best at this task. On the European territory, which includes Russia, straw was mainly used as the most economical additive to clay in housing construction.

In addition, at all times, straw was considered a waste material that was not suitable for livestock feed, but proved to be excellent in construction, where it was used to cover roofs and build walls. Houses made of clay and straw until recently were the main dwellings of the inhabitants of the steppe and desert zones.

This type of house has many advantages, especially its environmental friendliness. If you make the wall thickness of a certain size, and this is usually done, then a kind of microclimate is created inside the premises, which has a beneficial effect on human health. In such a house in the summer it is always cool, and in the cold season it is always warm.

Clay roof construction

The most difficult thing in construction earthen house- This is the decoration of its walls. It is impossible to stick wallpaper to them, the paint leaves after a short time. The main finish is whitewash. In modern conditions, this is the cheapest and not aesthetic option.

But with the advent of modern finishing materials solving problems with decorating the walls of a clay house has become easier. For instance, interior decoration can be done with drywall.

The wall will become even, and you can continue to fantasize about the interior. Facade decoration can be carried out using materials such as siding, various panels, facing brick etc. The main thing in this situation is to strengthen the foundation.

Ways to build a house out of clay

There are three ways to build a clay house. The first is to make bricks from clay with straw. This type of brick is called adobe brick. AT different regions the size of adobe bricks varies greatly from each other, from standard sizes ordinary brick to the size of a cinder block.

For the manufacture of adobe bricks, it is necessary to make a form of boards, designed to fit the size you have chosen. Clay mixed with straw is hammered into a mold and laid out on a drying platform. The main condition for the manufacture of adobe bricks is the presence of a flat area sufficient to accommodate a large number of bricks.

The second way is as follows. A formwork is installed into which the finished clay-straw mixture is hammered. This method seems easier, no need to mess around with making blocks.

But here, too, there are drawbacks. Firstly, a lot of time is spent on the assembly and disassembly of the formwork. Secondly, you will have to purchase boards for formwork. Although it is possible to use boards for these purposes, which will later be used for laying floors.

The process of this technology is that the formwork is first set to a certain height. Clog it all with clay, wait for it to dry.

Clay house

Then the formwork is removed and set to the next level, and everything happens until finished walls not reach a certain size, that is, the level of the ceiling. The most interesting thing about this method is that you can know exactly how much material is needed to complete the work.

The third method can be attributed to the fastest construction of a house. Strong rods will be needed here, which can be cut from trees or cut young growth. The rods in this case will act as reinforcement. First of all, thick rods are installed in the form of columns. Smaller sizes are woven between them. It turns out a kind of frame, which must be coated on both sides with finished clay. Clay in this case is used without straw. Now straw-based clay is kneaded, and with this solution we throw the frame again from two sides. It makes a pretty solid wall.

It takes some time for it to dry. The next operation is the alignment of the wall surface. This requires a solution based on sand and clay and plaster float. If further finishing will take into account the installation of drywall, then it is not necessary to level the walls.

Previously, plastering the walls of a clay house was considered one of the main operations. Were special masters who knew exactly how to properly coat the walls of the house with clay. Today it's all in the past. With the advent of new finishing materials this operation may not be carried out at all.

AT modern construction clay plaster gave way to professional finishing materials. But as before, it remains in demand among people living on their own land. In this article, we will tell you in what proportions a clay solution is prepared, and how walls and ceilings are plastered with this affordable and environmentally friendly material.

Where is clay plaster used?

For many years, clay plaster was used, perhaps, only for laying interior partitions, as well as for finishing and laying stoves and fireplaces. But, if you look at the old buildings, plastered with clay compositions, you can be sure that it still serves properly.

Partitions made of red brick are also very durable, in the laying of which cement-clay mixtures are often used. Moreover, unlike fragile drywall, heavy racks can be hung on them without fear of their fall.

Clay-sand mortar is most often plastered on wooden, clay (adobe) walls, not only outside, but also inside the house. Plastering with clay, in principle, can be any surface. The main thing is to prepare them correctly, as well as to choose the fat content of the clay and observe the proportions with additives (sand, sawdust, straw) in the solution.

This environmentally friendly material is able to absorb excess moisture and release it as needed. Clay plaster with the inclusion of flax or straw fibers looks original, so designers and craftsmen are increasingly using it as decorative finishes.

Advantages and disadvantages

Plastering walls with clay has many advantages:

Environmental friendliness; clay does not contain harmful impurities.
Fireproof: She is absolutely not afraid of fire.
This material easily adheres not only to concrete or brick, but even to wood. In the latter case, shingles are used to secure it.
Even a non-professional can work with plastic clay mortar.
It is able to "breathe", that is, to absorb moisture from the air and release it when the relative humidity changes, which is very important for creating a comfortable microclimate.
Adsorption. It has been noticed that allergy sufferers feel more comfortable in rooms finished with clay plaster. After all, clay is able to absorb odors and bind harmful substances.
It costs absolutely nothing: you can dig it up with your own hands in the nearest quarry or in your garden.
Good sound insulation and heat saving.

Despite the obvious advantages, clay plaster also has disadvantages:

Duration of drying of the surface - a layer with a thickness of only 1 cm will dry for 5 days. Thicker 5-10 cm layers dry in 2-3 weeks.
Moisture capacity. Due to the ability to absorb water, clay surfaces need additional protection.
Low strength. With cement mortar it certainly cannot be compared. Clay is easily scratched and chipped.

Specifications

By thermal conductivity clay-sawdust coating takes the second place after gypsum-perlite mortar - its thermal conductivity is 29 W / m × ° С. In its pure form, the thermal conductivity of clay is 69 W / m × ° C, that is, almost 1.5 times lower than that of a cement-sand mixture.

Another important indicator for plaster is vapor permeability. After all, moisture in order to avoid the appearance of condensate must be removed from the premises. Vapor permeability coefficient for clay = 0.11-0.15 mg / (m * hour * Pa). This is more than log walls. Therefore, clay is excellent for plastering wooden houses.

Density(weight to volume ratio) for clay is 1700 kg / cu. m. A brick has a similar density.

Consumption of clay plaster with a layer thickness of 1 cm is equal to 15 kg per 1 sq. m.

What clay is suitable for plaster?

The ratio of clay and sand in the composition directly depends on the fat content of the clay. Very oily clay requires much more sand. Proportions can vary 1:5 (clay-sand); 1:4, 1:3 (with medium fat clay) and even 1:2. If the clay is very thin, then sand can not be added at all. Please note that it is necessary to measure the components not by weight, but by volume. To do this, it is more convenient to use a bucket or a large jar.

To select the proportions of the clay solution, you need to determine the fat content of the clay. This is done in the following way.

Prepare 4 types of these solutions with different sand content and try to roll a small ball of 3-4 cm in size from each of them. Now throw each of them from a height of about 1 m.

The “correct” ball, when falling on a hard surface, should not change shape or be damaged much. If he flattened - the solution is too greasy. It will crack as it dries. If it crumbles, then the clay is skinny, and you need to increase its ratio in the mixture, otherwise the plaster will be fragile.

Also, to check the readiness of the solution, you can put a clay ball on a hard surface and flatten it, reducing its height by half. Ideally, small cracks should appear along the edges of the sample. If they did not appear at all, then more sand is needed. If the cracks are deep, then, on the contrary, clay is added.

You can try to roll out a long tourniquet 20-30 cm long with a cross section of a couple of centimeters from the prepared solutions. By experimenting and selecting the ratio of sand and clay, it is necessary to ensure that such a flagellum does not crack after bending.

Advice! If you want clay plaster to last as long as possible, protect it from moisture with a thin layer of cement (iron) or paint.

How to make mortar for plaster

You can prepare mortar for plaster without any complicated tools. We take the old large capacity- for example, a trough or a bath. Even if a large volume is required, it is not worth soaking more than 10-15 buckets - it will be difficult to mix clay with sand.

Pure clay, without admixture of earth and plant roots, must be soaked at least a day before and periodically mixed. In this case, it will be easier to work with it - it will be easy to knead it with your hands. Drain excess water. We remove all large lumps that are poorly moistened with water, and plant remains. Since we have already determined the quality of the clay and know the required proportions, we prepare the solution by adding the right amount sand.

Add liquid gradually so as not to overdo it. Continue kneading until you reach the desired consistency.

With a mixer or at least an electric drill, the cooking process can be significantly accelerated. Large quantities require a concrete mixer. By the way, in order for the clay to break perfectly in it, throw a couple of stones or pieces of brick into the water. They will help break up the clay and mix the solution.

Clay additives

For plastering fireplaces and stoves, asbestos, lime or gypsum is often added to the mortar to increase the strength of future plaster. They require quite a bit - 1/10 part. For example, if the ratio of clay and sand is 1:2, then asbestos is added to the mixture of 0.1 part and 1 part of lime.

Advice! Learn that for laying the furnace, cement that collapses under the influence of very high temperatures, not used. Only clay (preferably fireclay) and sand in a ratio of 1:3. For a small hearth, you can use proportions of 1: 2.

Fireclay (white fired) clay is often used for oven plasters. After exposure to high temperatures, it acquires the properties of a stone and becomes refractory. It is crushed and used in solutions in proportions of 1:3:1 (clay, sand, cement M400-500).

For oily clay, the amount of sand can be increased. Learn that the amount of cement is calculated from the sand. That is, the more sand, the more cement.

In the event that it was not possible to obtain high-quality clay without impurities of chernozem (and in some areas it has to be obtained from a great depth), it is better not to take risks and purchase ready-made mixtures for plastering and especially for laying bricks for stoves and fireplaces. After all, furnaces stacked on an unsuccessful solution, when it cracks, can begin to smoke.

Clay mortar with the addition of sawdust - perfect option for building insulation. Lumber in the composition not only improves the heat saving of the building, but also acts as a reinforcement of the plaster layer. However, this mixture is not very elastic, and it is not easy to smooth it. Therefore, often the hut is left without alignment. But after drying, the plaster with sawdust is not afraid of cracking and does not crumble.

Advice! If the solution is too thin, leave it alone for a while, and then simply drain off the excess water.

Wall preparation before plastering

Clay mortar due to lack chemical bonds with a plastered surface does not adhere well to a smooth base. Therefore, when facing a brick, before plastering, jointing is necessarily done.

For reinforcement wooden surfaces finished with clay plaster, use shingles. Application plaster mesh in this case is not very convenient. Since clay is not as malleable as gypsum, it will not bond well to the mesh.

Shingles are called narrow boards 3-5 mm thick, which are stuffed onto the wall with nails. Wooden planks are located at an angle of 45 °. Moreover, the nails should not enter the wall completely, but only half. The rest of them are bent and recessed into the wall. In this case, the shingle will hold better.

Clay plaster

The principle of working with a clay mixture, in fact, is no different from working with ordinary plaster:

Beacon profiles are also placed for alignment.
To obtain a durable surface without cracking, the thickness of each layer should not exceed 10-15 mm.
With strong slopes and the need to apply a solution of greater thickness, clay-straw or sawdust mixtures are used, which can be applied to walls reinforced with shingles in a large layer.
If necessary, a new layer is added on top of the first only after the surface has dried.
The walls after finishing with shingles are dust-free and wetted with water.
The surface is abundantly moistened so that it does not take liquid from the solution and does not weaken the plaster.
The solution is thrown with force to provide a better grip.
To reduce the formation of cracks in the solution, it is desirable to add fibrous additives.

The video below shows how to plaster a clay or wood wall.

Decorative clay finish

Recently clay colored plaster becomes one of the most sought-after materials for interior decoration. It is used in many decorating techniques and is suitable for emphasizing the commitment of the owners of the house to natural traditional materials.

Often the natural texture of the clay wall is complemented by the application of relief drawings or patterns. To do this, putty on clay with a fine-grained composition without impurities. Then, a layer of putty 3-5 mm thick is rolled with rollers, stamps, or a pattern is formed with your own hands.

The finish layer of the finish can be coated with a vapor-permeable casein primer or paint in various colors.

Here are some photos of clay in the interior.

Until recently, clay houses were considered housing for the poor. This was due to the minimal cost of its construction.

Clay roofing for a house

Clay as a building material has been used in housing construction for a long time. Today, history can confirm that not only houses for poor people were built from clay. Almost all over the world there are examples of how clay perfectly coped with the functions assigned to it, not only in the economical construction of housing, but also in the construction of monumental buildings.

Straw;
Small twigs of trees;
Reeds;
Bamboo;
And similar materials.

They were the best at this task. On the European territory, which includes Russia, straw was mainly used as the most economical additive to clay in housing construction.

Clay roof construction

The most difficult thing in building a clay house is the decoration of its walls. It is impossible to stick wallpaper to them, the paint leaves after a short time. The main finish is whitewash. In modern conditions, this is the cheapest and not aesthetic option.

But with the advent of modern finishing materials, it has become easier to solve problems with decorating the walls of a clay house. For example, interior decoration can be done using drywall.

The wall will become even, and you can continue to fantasize about the interior. Facade decoration can be carried out using materials such as siding, all kinds of panels, facing bricks and so on. The main thing in this situation is to strengthen the foundation.

Ways to build a house out of clay

There are three ways to build a clay house. The first is to make bricks from clay with straw. This type of brick is called adobe brick. In different regions, the size of adobe bricks varies greatly from each other, from the standard sizes of ordinary bricks to the sizes of cinder blocks.

The second way is as follows. A formwork is installed into which the finished clay-straw mixture is hammered. This method seems easier, no need to mess around with making blocks.

The process of this technology is that the formwork is first set to a certain height. Clog it all with clay, wait for it to dry.

Clay house

Then the formwork is removed and set to the next level, and everything happens until the finished walls reach a certain size, that is, the level of the ceiling. The most interesting thing about this method is that you can know exactly how much material is needed to complete the work.

It takes some time for it to dry. The next operation is the alignment of the wall surface. This requires a solution based on sand and clay and a plaster trowel. If further finishing will take into account the installation of drywall, then it is not necessary to level the walls.

Previously, plastering the walls of a clay house was considered one of the main operations. There were special craftsmen who knew exactly how to properly coat the walls of the house with clay. Today it's all in the past. With the advent of new finishing materials, this operation can be completely omitted.

Clay plaster, the composition of which is simple and literally lies under our feet, is increasingly found on construction sites as facing material for interior and exterior decoration. It is known that it was the main material for masters many centuries ago, why are we returning to this experience again today?

Plastering walls with clay - what is this process?

The return to the ancient traditions of construction is not accidental. Modern mixtures for home decoration practically do not exist without chemistry, which eventually harms the body. The cheaper the composition, the more harmful. Expensive plasters are not available to everyone, and they do not become less chemical either. Clay interested the consumer primarily in its ecological cleanliness, because the ancient masters did not have a chemical industry.

And even not so old village buildings where this material is used are still functioning properly, which means that the clay does not crumble after a couple of years, but behaves like a full-fledged durable natural finish, not only not harmful, but even useful to humans. Plastering walls with clay is cheap, and for those who are especially thrifty, there is an opportunity not to spend a penny on components, but to dig them yourself from the nearest quarry, river, or even in your own area. After all the mixture requires only clay and fine sand. But this is an activity for extreme people, because the depth of good clay is about 1.5 m, and it will take a lot of it.

Even if you buy ready mixes they are pretty cheap. When choosing, you should only pay attention to the place of extraction, because clay is a good adsorbent of harmful, and sometimes radioactive contaminants. There are no problems with the color of the plaster, because natural clay can be of several shades, roughly representing the entire palette from red-red to blue, and this depends on the place and depth of extraction. Dyes, although natural, are rarely added, and natural fillers, such as straw, can be used for a textural effect.

Clay plaster - composition and properties

In addition to low cost and environmental friendliness, this has a number of advantages. Therefore, before instructing how to plaster with clay, consider what we win and what we lose. The layer that you get on your walls will not fall into decay very soon, which will be indicated by numerous cracks, because the clay is very elastic, and endows this quality and plaster mixture. Her appearance will always be presentable and original, as a natural material she is not afraid of humidity, temperature fluctuations, wind and even moderate earthquakes. Its density creates the effect of conservation of the room, not letting in harmful substances, for example, exhaust from the street, it is believed that even electromagnetic radiation is to some extent delayed by such walls.

After ten years, the first crack may appear, but the restoration is done almost instantly, and it is unlikely that it will be necessary to cover the entire wall, it is enough to fake trouble spot. A layer of clay plaster breathes well, allows moisture and steam to pass through, the indoor microclimate will be almost ideal of all options. And you can not wait for unwanted guests in the house, various kinds of insects simply cannot gnaw through the strong bonds of natural clay. The advantages can be attributed to the hypoallergenicity of this material, as well as the cleanliness of not only the layer on the walls, but also the construction process. Harmful waste is not generated, because everything is taken from nature, and it is not shameful for her to return the surplus.

It would be unfair not to mention some of the difficulties that will have to be faced. If you are doing it for the first time, then you will have to feel all the capriciousness of clay plaster, because it is not so easy to prepare it, because there is no recipe, readiness is assessed by a practical method. We will try to help you master it, but if available experienced craftsman it is better to take him for help. By the way, finding such a person is also not easy, because clay is not yet so popular, and earlier it was not taken into account at all, few people know how to really competently work with it. The plastering process itself is quite lengthy, you will have to wait a long time for each layer to dry, and if you do the exterior decoration with this material, then restoration will be required almost every year. The plaster, although it will not crumble, will often crack.

How to plaster with clay - the sequence of work

Let's proceed to the description of the work itself, because there are many nuances here, so we will no longer be distracted by theory.

How to plaster with clay - step by step diagram

Step 1: Preparing the base

Clay plaster is heavy, so adhesion must be very high. To do this, it is desirable to have tangible roughness on the wall, but it is better to build a shingle (wooden grate). If the walls are brick, then clean the surface of any remnants of the previous finish and slightly open the seams. Then the clay will lie confidently and for a long time. A wooden house should definitely be with shingles, making notches on logs is a thankless task. You should not use it from metal, since clay is unlikely to be able to squeeze into it with high quality, it is too dense.

Step 2: Preparing the mixture

A pure mixture of clay and sand is used for finishing plaster, as it is very "cold". Clay must first soak in water for 2-3 hours, then a little more water is added and thoroughly mixed to obtain a homogeneous mass. Then sand is poured into the container, the composition is mixed again. Here are the proportions to choose empirically, they will depend on the initial fat content of the clay. This is checked in several ways, but the fastest and does not require an ideal eye is the ball method.

To begin with, achieve such a state that the mixture does not stick to your hands, this is done by gradually adding water. Then we take a little of the mixture and sculpt a ball 2 cm in size. You should put it on a hard surface and flatten it, but not to a thin pancake, but to an impressively plump one. Now pay attention to the edges, if cracks have formed on them, then the solution is non-plastic, more clay is required, if there are no cracks, then you guessed it with the proportions and you can start working. On average, sand for mortar requires 50-80%.

The main plaster solution is prepared with additives, it can be sawdust, straw, needles. Such a solution holds stronger, i.e. fillers give a reinforcing effect and keep heat better. The "warmest" - clean clay mortar with the same additives, but it is not plastic and will definitely require finishing, since the cracks will not take long to wait.

Step 3: Plastering

The first layer is thrown in inaccurate lumps, and in order to better stick them to the surface, you need to make some efforts, i.e. press the clods, and not spank with a spatula, as is done with other plasters. If this layer is the only one, then it needs to be perfectly leveled with a grater, if not, then it’s enough just to roughly bring the surface to the same level. It is necessary to let the layer dry, it will take a little more than a month in the summer, and in the winter all three.

Then the next layer is applied, usually "cold", see its description above. Its thickness is small. You can also use a grout, where cement is also added to clay and sand. The ratio of clay-cement-sand is 1:1:3. Now the surface should be smooth. And this layer should dry out, give it a few weeks. Do not try to speed up the process, forced drying will spoil the coating immediately. Further, the wall can be decorated, painted or left in a natural color. If some kind of finishing is still conceived, then a number of additional preparatory work eg primer.

Ecology of consumption. Manor: As already mentioned, a clay house and clay plaster have many positive sides. First of all, it is environmental friendliness. However, clay has one big drawback - it is not resistant to moisture.

As already mentioned, a clay house and clay plaster have many positive aspects. First of all, it is environmental friendliness. However, clay has one big drawback - it is not resistant to moisture.

Modern technologies make it possible to make a clay house and clay plaster more durable and resistant to adverse factors, primarily moisture.

In the recent pastI plastered the walls country house built from white brick, clay. I also made the floors in the house out of clay. I made the spray from clay with the addition of pine needles, and the finishing layer was made from a clay-sand mortar.

After drying, the surface of such plaster is not too strong - when you run it along the wall with your hand, there is a slight shedding of sand. To pin upper layer clay plaster, made of clay-sand mortar, I treated the walls with freshly slaked lime in two layers. I draw your attention: it is freshly slaked lime, since it tends to harden after drying.

Thus it turned out solid protective layer, which reliably protects the walls from moisture, firmly fastens the top layer of clay plaster, and besides, it does not “take” when running along the wall with your fingers.

However, this layer is quite thin - only a couple of millimeters. And this layer does not protect the plaster from moisture from reverse side i.e. from the side of the wall. So, if the wall gets wet for some reason (for example, the roof is leaking), then this layer of lime can simply peel off and crumble. After the wall and plaster have dried, it will be necessary to treat the surface of the plaster with lime again.

You can go the other way.

Lime can be added to the clay-sand mortar for plastering. Then the layer of plaster will be much stronger and already initially it will be less susceptible to moisture.

You just need to remember that you need to work with such a solution in rubber gloves and avoid splashing when working on the skin and mucous membranes. Lime tends to corrode the skin and burn the mucous membranes.

Clay-sand mortar with the addition of lime has one important feature- such a solution becomes stronger and stronger over the years, and after decades its strength is not inferior to strength silicate brick. Such a solution can no longer be reused.

Here I want to make one important remark. Freshly slaked lime should not be taken literally - just extinguished and immediately used. No. Immediately after slaking, the lime heats up strongly and swells strongly, then gradually cools down. At the same time, she continues to slowly swell.

You can use freshly slaked lime no earlier than a day later. And better - through two.

If you do not complete the process of slaking lime to the end and start working with it, then the solution to which it is added will be torn apart by lime when it dries, which continues to increase in volume.

Today you can do without lime. OnFor example, plaster the wall with a clay-sand mortar (layer no more than 1 cm), and after the plaster has dried, treat the wall with a deep penetration primer.

Such a primer penetrates clay-sand plaster to a depth of 1 cm, or even deeper. Clay plaster treated with such a primer becomes quite durable - it no longer crumbles when held over its surface by hand. Even with a grater for leveling walls and ceilings, such a surface is no longer so easy to process. Therefore, if you want to level the surface of clay plaster with a float, then this is best done before treating this surface with a primer.

If the room in which the walls are plastered with clay has high humidity, then after processing the clay plaster with a deep penetration primer, you can additionally treat the walls with a primer with waterproofing properties.

Such a primer forms a moisture-proof layer on the surface of the wall and the plaster is no longer afraid of moisture drops in the room. However, such walls no longer "breathe" as it happens with ordinary clay plaster. Here you have to compromise.

Treatment clay walls a primer has an advantage over treating the same walls with freshly slaked lime if it is intended to wallpaper the walls.

If it is supposed to paint the walls water-based paint, then a thin layer of satengypsum can be put on top of the clay plaster - literally a couple of millimeters if the wall is even. If there are large irregularities on the clay plaster, then the wall will have to be leveled using starting putty(isogypsum), and only then put satengips ( finishing putty) and smooth with a grater. published