How to prepare clay mortar for plasterCategories

Finishing decoration

At the final stage, after the finishing layer has dried, the walls are treated with lime. Traditionally, the procedure involves the application of several layers. Alternatively, the surface of the clay walls can be processed with fine-grained sandpaper. After grinding with sandpaper, the application of a primer is mandatory. It is better to do this twice at intervals for complete drying. Further, the clay walls are covered with a gypsum mixture. The prepared surface can be decorated with paint or wallpaper.

There are many options and nuances of finishing clay walls. In some cases, for finishing with plaster, a mortar containing lime, but without cement, is used. In addition to the gypsum mixture, asbestos can be used. The quality of clay largely determines the proportions of plaster solutions at all stages

When choosing it, it is very important to exclude the presence of minerals with increased radioactivity in the composition.

Compliance with all recommendations will make it possible to equip housing with environmentally friendly materials that are independently able to form a microclimate in the room and reduce the cost of using additional installations that cool or heat the air.

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>House in the garden

How to apply plaster

Before application, the surface must be cleaned of the old finish layer. Then wash the surface. Apply a waterproof primer with antibacterial properties to the wall. It is better to apply in two layers, this will increase adhesion, and the surface will be smoother. Apply a new layer until the old one is completely dry. Check with your hand in an inconspicuous area. If the surface is not sticky, then the primer is dry.

Plaster can be applied in several ways:

1. splashing;
2. Priming;
3. Finishing.

Wet the wall before spraying and apply to the surface with a spray bottle. The layer should not exceed half a centimeter for concrete. The primer solution is thicker, applied with a spatula to the surface. Wait a bit and then level the wall. If cavities are formed, add a little mixture, and if there are bumps, remove it. Finishing is done with a spatula. The solution is applied in several layers.

Use of various additives

If the plaster composition is not properly prepared, then its adhesion to concrete or brick surfaces will be of poor quality. With the right consistency, the solution will slide off the trowel in 8 seconds with one mass. If the mixture drips or sticks firmly to the trowel, the preparation is not done correctly.

To increase the adhesion of the solution, special additives are used, corbocellulose or polyacetate adhesives, they are in powder form and dissolve in water. Such additives are able to displace air from the surface of the plaster composition. As a result, the plastered surface has a smooth and even structure.

Also, for surface preparation and preparation of plaster, KMS compositions are used in liquid form, they are used to prime walls, and added to the solution.

To improve the plasticity of the 400 cement-based solution, use a conventional washing powder or synthetic-based liquid detergent, add 70 grams per 50 liters of the composition.

Oily clay has a similar effect; 100 grams are added to 15 liters of water. It is carefully ground into a liquid, and then added to a mixture of cement and sand. At the same time, the plaster composition dries longer than a conventional mortar. If too much clay is added, after drying, the surface may crack.

Instead of clay, you can use lime paste, such a solution is prepared for plastering external walls or basements. If the surface is subject to temperature changes, then you need to use an additive made of chopped fiber material, which is based on a polymer - fiberglass.

Preparing the mixture

Self-production of cement plaster consists in mixing all the necessary components and adding plasticizers to improve the quality of the mixture. The use of sand as aggregate is traditional. Such a solution acquires the properties of strength and resistance to cracking, which is so necessary for the surface.

Let's find out how to make a cement mortar for self-plastering walls and learn tips from professionals:

• The novice master has no idea what the brands of cement mean. Therefore, when choosing them, start from the specifics of your work. For ordinary wall plastering, M400 is suitable, for workspaces, garages and where you need to save money, choose M300, but for the basement of a building and places with high humidity, you should buy Portland cement M500
• The mixture begins to dry already 10-15 minutes after application to the base, so you should not hesitate when spraying and smoothing. In order to completely dry the plaster will take from 10 to 12 hours. If you want to maximize the strength of the plastered wall, then you will need to exclude all additional finishes and mechanical influences for about a month.
• It is necessary to choose the correct fraction of sand for cement mortar - it can be from 0.2 to 0.5 mm and from 0.5-2 mm. Make sure that there is no organic matter in the sand, otherwise it will cause a rotting process in the future.

Table of proportions depending on the brand of cement:

Grades of cement	Mortar grades
200	150	100	75	50
300	—	1:2,5:0,1	1:3,5:0,2	1:4:0,3	1:6:0,6
400	1:2,5:0,1	1:3:0,2	1:4,5:0,4	1:5,5:0,5	1:8:0,9
500	1:3:0,2	1:4:0,3	1:5,5:0,5	1:7:0,8	—

Most people are interested in how long cement plaster will dry on a wall? First of all, the drying process depends on the ambient temperature - it is forbidden to use artificial drying for indoor premises and allow drafts. External walls will take approximately 24 hours to dry, but the strength indicators will gain their strength in about a month after finishing. In what sequence to prepare cement plasters and how to make the right mortar yourself:

1. The main components in dry form must be taken in equal proportions, after which it is good to mix them together
2. To improve the quality of the plaster, it is necessary to sift the resulting mixture through a sieve.
3. At the next stage, water is added to the mixture - the resulting solution should be homogeneous
4. Cement plasters are not plastic, so there is one trick in which washing liquids are added to plasters at the rate of 30-50 ml per 5 liters of water

How to prepare a mortar for wall plaster

Wall preparation

In order for the work to be done efficiently and for a long time, it will be necessary to prepare a clay wall, as well as comply with certain rules and recommendations.

First of all, you need to pay attention to the base of the wall, because if it has low strength, it makes no sense to carry out plastering. Therefore, before proceeding to the main process, make sure of the strength and, if necessary, strengthen the wall

This will require:

• in case of detection of large cracks, we strongly recommend sealing and filling the voids with gypsum plaster or clay mixture, which can be prepared from clay, sand and then add half a bucket of water with sawdust;
• if the wall has been attacked by a fungus, you will need to rid it of moisture and, after it dries, treat it with an antiseptic. Processing is best done two or three times to make sure the result;
• before proceeding to processing, the surface will need to be completely rid of the old finish.Also, dirt and dust must be removed from the wall, it must be clean and smooth.

After leveling and cleaning, the clay wall will need to be treated with a primer

Priming will increase the level of adhesion, which is extremely important for a clay surface. As a primer, it is better to use deep penetration mixtures.

Clay absorbs moisture well, so a lot of solution will be required. We recommend applying two coats of primer so that the plaster is well fixed on the wall in the future. Remember that priming is a mandatory process, and if you decide not to, you risk putting the entire job at great risk. Now let's talk in more detail about the choice of plaster.

Clay Plaster Recipes

Clay plaster recipes exist in various versions. However, there are no universal ones, because everything depends on the quality and composition of the materials, and especially clay.

The most important thing is to experiment, test, make test batches and see what happens.

We offer you several ready-made options, but in any case, you need to test them and try to make your own recipe.

Recipe No. 1 Sandy-clay

Clay should first be soaked for a couple of hours in a container, and then add a certain amount of water. Then mix the contents until smooth. Then sand is poured and mixed again.

Components are added in the following proportion:

However, this composition of clay plaster is "cold" and has a high thermal conductivity. That is, it will let the cold in and let the heat out. Therefore, it is used only for finishing cladding.

Recipe No. 2 Sand-clay with fiber

The most common recipe for clay plaster is to add fiber to it. The fiber binds the plaster, making it stronger, more flexible and durable.

Straw is most often used as a fiber, but hemp fibers, cattail, reeds, animal hair can also be used. Why use fiber and what its advantages are, read here >>>.

Such a solution is quite warm, durable and strong.

Recipe No. 3 Sandy-clay with additives

Additives in plaster can greatly improve its quality. For example, to increase plasticity, durability, give color and structure plaster.

The most common additives are wheat paste, manure, cactus juice, casein (milk protein), linseed and rapeseed oil. Read more about supplements here.

To prepare the solution, mix:

Option 1

How to cook wheat pasta, read here>>>.

Option 2

Kaki Hunter, "Earthbag building: the tool, tricks and techniques"

Option 3

Baron Leopold Korf, April 17, 1838, "On Clay Plaster"

Option 4

Maya Creek Education in Sustainability

Maya gives tips on how to knead 3 layers of clay plaster:

All this must be mixed to a paste consistency. This consistency can easily penetrate deeper into the straw, forming a very good base for subsequent plastering with clay.

The mixture should be thick, as the layer will be several centimeters thick. The mixture takes longer to beat and becomes more sticky.

Slightly damp kneading is needed for the first layer, as a base, to create a solid foundation. Subsequent, thicker mixes will adhere to this initial coat much better than directly on the wetted primer.

However, all these solutions must be checked specifically on their materials: make trial batches and apply plaster. And also, modify, experiment with additives and bring out for yourself the most pleasant and high-quality consistency.

Properties and features of clay solutions

Interest in such a finishing material as clay is not accidental. In addition to the fact that materials of this kind have an acceptable price, they are fully consistent with the new trends in construction, dictating the need to use natural materials. In addition, clay, as a finishing material, has a number of advantages.

Benefits of Clay Finishing

The main advantages of using clay finishes are:

• The material is hypoallergenic, acting as a natural filter;
• Regulation of the microclimate in the premises by absorbing excess moisture from the atmosphere;
• Preservation of facade surfaces during exterior decoration;
• No construction waste and the possibility of reuse;
• Exclusively natural environmentally friendly components of the composition;
• Ease of preparation and ease of application;
• Excellent protective performance;
• The elasticity of the created coating, which prevents the destruction of the structure.

Pattern on the finish

Disadvantages of finishing with clay

When choosing clay as a finishing material, the following important nuances of its use should also be taken into account:

• Long period of application and drying of the finish;
• Clay plaster mortar, when used on natural surfaces, may crack over time, especially if it is exposed to scorching sun or high levels of humidity.

Clay plaster wall

As you know, clay loses its properties in the presence of a large amount of moisture, so before moving on to finishing, make sure that the primer is completely dry. For cladding, you will need a nylon mesh over the entire area of ​​\u200b\u200bthe surface to be treated. The standard grid width is one meter. It is necessary to fasten the strips with an overlap. Remember that this design is used only when applying the first layer, it will not be needed later.

Installation of kapron mesh

The grid can be installed in two ways:

• you can roll the roll from top to bottom and fix it with a construction stapler. However, this method has its drawback. When applying plaster, the structure can be deformed and a protruding “wave” is formed;
• you can fix the grid with the plaster itself. Apply a small amount of mortar under the ceiling and attach the mesh there. Press the structure with a spatula to ensure the quality of the installation. Then roll it down to the floor. Further fixation will be carried out already in the process of work, using gypsum plaster.

Mortar application

When the installation of the grid is completed, you can proceed to applying the first layer. It is necessary to apply starting plaster on a clay wall in one direction, it is better to do it from top to bottom. The solution is applied with a wide spatula and then spread over the entire area of ​​the coating. To align the wall, you can use the rule. If, after processing, there are irregularities on the wall, it will be necessary to use three or more layers.

Remember that the second layer can be applied only after the first has completely dried. For clay walls, this factor is especially critical, as they are afraid of moisture.

After the first layer is applied, and you make sure that the walls are aligned, you can proceed to further processing. We also recommend sanding the coating, this will help get rid of minor defects. However, then the wall will again have to be primed. The final layer is also applied with a wide spatula and smeared over the entire plane of the wall. After the mixture dries, the surface can be rubbed to make the wall perfectly even and smooth.

After the solution has completely dried, you can think about further finishing, for example, wallpapering. Before gluing, the wall must be primed again to increase the level of adhesion. When the primer dries, you can begin to glue the wallpaper. We recommend watching the following video to see the process of plastering clay walls in practice:

What are solutions made of?

What are the solutions

• Clay;
• Lime-gypsum;
• Lime;
• Cement-lime;
• cement;
• Terrazitic.

Regardless of the type, the solution should be viscous. Cement mortars are suitable for indoor and outdoor use. Such a solution is not afraid of moisture, which means that it can be used in a room with high humidity. The cement mixture is the strongest of all, however, the process of its manufacture will take more than 12 hours. Lime mixtures are afraid of moisture, which means that they can only be used in rooms with moderate humidity. It is also suitable for exterior decoration, but only if the surface is not constantly exposed to water. To ensure the strength of the composition, gypsum is added. Work with such mixtures should be fast: they will harden in half an hour after manufacturing.

Clay mixtures are used for finishing wooden surfaces. Clay is afraid of water, which means it can only be used in dry rooms or in rooms with normal humidity. The composition of the plaster should include three components: these are binders for adhesion, filler for strength and water to create the desired consistency. If it is necessary to add some more properties to the characteristics, then a comparable substance can be added.

The surface is plastered in several layers. You need to decide what exactly you are plastering for? If for alignment, then you need the most astringent composition. If you use plaster as a primer, then it should have a medium viscosity. As an atomizer, the presence of binder should be kept to a minimum. In the manufacture of cement mortar for spraying, the ratio of binder - aggregate is 1: 3, primer 1: 2, and finishing mortar 1: 1.5. Clay mortar implies the presence of aggregate 4 times more than the clay itself. And the lime mortar is twice as much.

What can be added

1. Lime;
2. Gypsum;
3. Liquid soap;
4. PVA glue.

Lime is added to improve elasticity. In addition, its presence will make the solution less susceptible to moisture. Gypsum will allow the mortar to harden faster. This is especially true for cement mortar. But do not add too much, otherwise it will harden, right in the mixing container.

Liquid soap adds elasticity and increases adhesion, your solution will be more plastic, which means it will lie on the surface more evenly. PVA glue will add strength and adhesion to the material. Subsequently, during operation, the solution will not crack. The most common mortar filler is ordinary sand. Quartz sand is the highest quality, but others will do. Sand must be sieved to remove debris.

Required Tools

• Bucket for mixing. Any container will do, as long as it is clean.
• Measuring container
• Drill or perforator for kneading.
• If there is no drill, then a shovel, a strong stick, or anything that can interfere with a heavy mixture, will do. But it will be quite difficult to do it manually.
• Binder
• Aggregate
• Water

If necessary, prepare additional additives to improve the characteristics of the mixture. How to calculate in what quantities you may need components? Consumption of cement for wall plastering: Calculate the surface area and multiply by the layer of plaster. The width of the minimum layer is 6mm.

Features of the composition for plaster

To prepare a high quality composition, all dry materials are sifted through a special sieve. The solution is ready to work if it has a homogeneous mass, the desired fat content, and is well retained on the surface, does not crack after drying.

Solutions can be lean or have increased and normal fat content. Fatty compositions include a high content of binder, as a result, cracks appear on the plastered surface. With a normal composition, all components are added in the correct proportion. Lean mixtures have a large amount of filler, while the plaster layer loses its strength, but the coating does not shrink or crack.

The fat content is determined by the object with which the solution is mixed. If the mixture sticks strongly, then it has a fatty composition, it is necessary to add a filler, that is, sand.In the absence of adhesion, the composition is considered lean, so you need to add a binder. The solution is considered acceptable for work if the adhesion is of an average degree.

Clay plaster composition and recipe

There are many compositions of clay plaster, but there is no universal recipe, the quality of the composition depends on the components. And the main one is clay for plastering walls, it is divided into 2 types: light and oily, the latter is most suitable.

To check the quality, you should roll a ball of small diameter from clay, put it on a flat surface and flatten it. If the edges remain intact, then the material is suitable for plaster, cracks have begun - the composition is of little use. Another test is to roll up a flagellum with a length of 200-300 mm, a section of 10-20 mm and carefully bend it; the edges of the quality material do not crack.

Ways to check the quality of the material

Recipe table, proportions in parts:

Clay	Gypsum	Sand	Cement	sawdust, fiber	Lime	Asbestos
3	1	1			2	1/5
4		2	1		1	1/25
1		2			1	1/10
1		3
1		3		0,5-1

For plastering furnaces, fireclay clay 1 hour: 2 hours sand: 1 hour should be used. cement.

Due to the fact that there are a lot of recipes, we will analyze the characteristics of the most popular:

• Sand-clay mortar for wall plastering - used for finishing, has a high thermal conductivity, therefore it is not suitable for the base layer.
• To improve the thermal insulation characteristics, finely chopped straw or sawdust is added to the solution of clay and sand, in the modern version - synthetic fibers (fiber).
• Clay plaster with sawdust, without sand. The composition dries quickly, loses elasticity, is difficult to work with, but the finish is very strong and durable.

Tip: To increase the elasticity of clay plaster, it is recommended to add dung, wheat flour. To improve thermal insulation - finely chopped straw, reed fibers, hemp, wool, cattail.

For a smooth finish coat, a clay-sand mixture is suitable

How to mix the solution

So that clay plaster does not lose its qualities, it must be prepared according to strict rules:

• Clay is crushed, placed in a container, filled with water, left for a day.
• Grind through a construction sieve, the cell is not more than 3 * 3 mm.
• It is mixed with sand and other dry ingredients are added, the composition is well kneaded so that it easily leaves the hands.
• Chopped fiber, straw, sawdust, etc. are added. The smaller the fraction, the easier it is to put the plaster on the walls, the layer will be smoother.
• Dilute with water to the desired consistency (thick sour cream).

Correct material consistency

Creating a Clay Finish

Before proceeding with the application, you should decide on many important questions.

How to choose the type of solution

As the main criteria for choosing the recipe of the created material, one should take into account such important factors as the required thermal conductivity and surface characteristics:

Clay composition with felt is the most durable and warm option. This composition is suitable for roughing exterior walls;

Roughing

Let's add sand to the clay-felt mixture, and its plasticity and thermal conductivity parameters will decrease. Such a mixture is suitable for processing wooden surfaces, in which thermal insulation is already at the highest level, due to the properties of wood;

Clay-sand material

A mixture of clay and sand is more suitable for finishing surfaces, outside or inside a building.

You should also be aware that any clay solution is suitable for application to various types of materials. Plastering wooden, brick, concrete or other substrates does not require changes in the application technology.

What tools are needed

Tools

In order to start the plastering process, you should prepare the following tool:

• Mixing container;
• Shovel;
• Buckets;
• spatulas;
• Metal brush;
• Sieve;
• Plaster metal mesh;
• Nails or screws for attaching the mesh;
• Hammer or screwdriver.

If the finishing areas are large, it would be wise to use a concrete mixer.

How to make a solution

In order to understand how to plaster clay walls, the following step-by-step instructions for preparing the mortar should be studied and executed in practice:

1. Select the proportions of all the ingredients of the mixture according to the type of clay used. The plasticity of the mixture is the most important indicator of the correct recipe;
2. Soak the clay in water for about a day;
3. Stir the swollen material;

Mixing

1. After soaking and stirring, the clay should be filtered;

Straining

1. Sift sand and sawdust if you plan to use them for mixing material. The quality of the future coating depends on how pure these components of the mass will be;
2. Gradually add water and other ingredients of the mixture to the clay in small portions. Thoroughly mix the solution, bringing it to the desired consistency;

How to check the level of plasticity of the resulting solution?

In order to make sure that the proportions of all components of the composition are selected correctly, the quality of the resulting mixture should be checked in one or more of the following ways:

1. Take a closer look at the resulting mass. The correct consistency is thick sour cream or mashed plasticine;

plasticine density material

1. Roll a ball out of clay and press it down, flattening it to a thickness of 1 cm. The correct solution will flatten out without forming cracks along its edges;

flattening method

1. Roll up the ball and drop it to the floor effortlessly from a height of 1 meter. After falling, the solution of the desired consistency will not crumble, will not crack, and will not change its original shape too much;
2. Roll a clay rope with a diameter of 2 cm, a length of about 20 cm and bend it into an arc. The edges of the tourniquet should not crack.

Bend test

Remember, it is the correct consistency of the mass that determines the strength of the coating being created and the duration of its operational period.

How clay finish is applied

Instructions for the production of clay finishing works include the following steps:

1. Solution preparation;

1. Fixing on the surface of shingles or mesh;

Net

1. Application of the first layer. Clay is applied to the mesh in chunks with a maximum layer thickness of 3-5 cm. The first layer is not leveled to ensure better adhesion;
2. Applying a second coat after the first is completely dry;
3. Leveling the second layer with a spatula;

Surface leveling

1. Cleaning the surface after the second layer has dried;
2. Application of the final, as thin as possible, layer with a material of a more liquid consistency.

The use of such material as clay plaster mortar in wall decoration will delight the owners not only with its naturalness, but also with its profitability. The whole process, although it takes a lot of time, is quite interesting and absolutely not difficult.

In the photo - an example of an internal natural finish

And the video in this article will allow you to get acquainted with some important nuances of the application process.