Plastering is an integral stage of any repair work. Thanks to this process, the consumer properties of the treated surfaces are improved, and the reliability and durability of the walls is increased. High-quality prepared and correctly applied plaster prevents the spread of mold and fungi, removes all irregularities, chips and mechanical defects, and also helps strengthen the foundation.
Features of plastering – 3 layers
Mortar for plastering walls is easy to make with your own hands. It is necessary to level the surface. This operation is required both when performing exterior finishing, and internal. The characteristics and requirements depend on the place where the essence is applied. Thus, to carry out repair work indoors, you will need a technologically advanced and plastic mass, while external mixtures must first of all be resistant to changes in pressure and temperature, frost-resistant and resistant to moisture.
Solutions are applied to surfaces of all types and types. Plastering of plywood, chipboard sheets, wooden elements, cinder blocks and foam concrete, brickwork, concrete. Making at home suitable composition It is very important to pay attention to the adhesion of the finished product when choosing components and proportions.
The correct technology for applying plaster to the ceiling and walls includes three main stages:
- The spray is the first layer that needs to be applied to the building base. It is necessary to fill and level the largest pores and surface defects, as well as to ensure an appropriate level of adhesion and cohesion of subsequent plaster layers. When forming it, additional elements, such as lime and clay, are not used, and the thickness of the coating should not exceed 4 mm.
- The second level, which is called soil, is significantly larger in volume than the previous one and reaches 20 mm. Unlike liquid spray, this layer’s consistency is more consistent with thick plastic dough. Its task is to maximally level the base plane, regardless of its roughness.
- The last stage of work is the application of a coating to the surface, which is required for the final smoothing of unevenness and defects in the base. The thickness of the layer is from 3 to 5 mm, and enough water is added to achieve the maximum level of plasticity and viscosity of the solution. After covering, all that remains is to whitewash or paint the walls or glue decorative wallpaper on them.
What components are needed to prepare the mixture?
Many beginners, trying to make a plaster solution with their own hands, disrupt the mixing process from the very beginning. This is very important, since quality and correct mixing determine key characteristics ready-made composition. The main components include water, filler and binder. If necessary, enter Additional materials, including various additives and plasticizers.
Clay and lime can play the role of a binder. But the most popular and in demand is cement. It is excellent for preparing a mixture that is later used for external or interior decoration. At the same time, it is the most expensive option, since the other ingredients are seriously inferior to it in terms of quality, reliability and strength.
When choosing among many varieties, the easiest way is to choose M400 cement. This dry mixture is universal because it meets all the requirements of GOST, as well as apartment owners. Excellent for treating bathrooms, kitchens, hallways and, of course, living rooms. If the budget is limited, and repairs are carried out in low-impact structures, such as basements or plinths, then rational decision will be the purchase of Portland cement M300.
The strength of plaster is influenced by many factors, but the most important is the brand of cement. The higher this indicator, the better the quality of the solution.
Having decided on the binder, all that remains is to deal with the filler. Here the only and undisputed favorite is ordinary sand. It is recommended to take pure river fine fraction, which will ensure maximum mixing of all the ingredients of the future plaster. Together with cement it forms perfect material, characterized by resistance to cracking and high level strength.
The simplest and most popular cooking proportion plaster mixture cement-based includes one part binder and three parts sand. This recipe is suitable for almost any room. Water is added until the essence reaches the required viscosity level. For rooms with normal moisture levels, you can add a little more filler. If you want to achieve plasticity, then the correct ratio involves using one portion of cement and two parts of sand.
There are many plasticizers and additives designed to increase the softness and pliability of the finished plaster, change the hardening time and various characteristics of the solution. Home craftsmen often add detergents, soap, adhesives like PVA. Thanks to such materials, the adhesion of the essence to the concrete base, and also increases the level of protection against fungal bacteria and mold.
A big misconception is associated with the technology of mixing the mixture. For some “experts,” the order in which components are added does not matter. Many people first pour water into a container, then pour in cement, sand, lime and other materials. The problem is that the dry substance, after entering the liquid, turns into small lumps. It will take a lot of effort to stir them until the desired consistency is achieved.
To ensure a high-quality and homogeneous solution, experienced craftsmen It is recommended to do the following:
- 1. Initially, you need to sift the sand using a sieve with small cells. Otherwise, all debris and large particles such as shells, pieces of silt, pebbles, and organic debris will end up in the solution. During plastering, they will leave grooves on the surface of the wall, clinging to the spatula.
- 2. After this, you need to pour dry cement into the sand and mix everything thoroughly. If the filler is wet, it will need to be dried - mixing will be much easier when both components are dehydrated.
- 3. Only after this is water added, and gradually, while the solution itself is constantly mixed. It is recommended to pour in new portions of liquid at a time when it is almost impossible to interfere.
Types of plaster mortars - different options
For preparing mixtures for treating external and interior walls many different components are used. Thus, a solution in which cement and lime act as a binder can boast of great popularity. This essence is well tolerated low temperatures, the impact of direct sun rays, counteracts the appearance of mold and fungi.
Unlike the usual cement plaster, lime analogues are characterized by a high level of plasticity and viscosity. This has a positive effect on their adhesion index, thanks to which they instantly and firmly adhere to the bases of walls and ceilings of any type and type.
In rooms with normal humidity It is worth using lime plasters, which dry quickly and absorb excess moisture. This composition has proven itself best for brick surfaces. The lack of cement affects the strength and reliability of the mixture; moreover, it hardens within three days. But this factor allows you to prepare fairly large volumes of essence, because if you wish, you can always add water if the substance in the container begins to harden.
It is recommended to use additives such as gypsum to coat and treat wood, stone and fiberboard substrates. In combination with cement and lime, the plaster is very durable and flexible, but it is not suitable for wet walls. The presence of this substance causes a high rate of solidification, which makes it impossible to prepare the mixture in large volumes or “revive” it using ordinary clean liquid.
Decorative cement mortars and glazing plasters, which require additional investments money and strength. Using such mixtures you can perform finishing halls, corridors and hallways. In addition to the basic binder ingredients, many other materials are added, including minerals, mica, slaked lime, marble chips.
If it is necessary to give a certain shade, which is typical for Venetian plaster, it is recommended to infuse color pigments. You can purchase all of these additives at the same hardware store that sells bags of cement and lime.
If you plan to apply the decorative mixture in baths or near a stove, then you will need to increase the level of durability and resistance to extreme high temperatures. To do this, it is recommended to add fireclay powders and special refractory clays. As a result of this process, cement with the addition of these materials produces a strong essence that is resistant to heat, thanks to which it can even be used on the walls of fireplaces.
What is useful for kneading - let's move on to the tools
Mixing all the components of the solution is carried out in two ways - machine and manual. The easiest way to prepare the mixture is in a regular enamel bucket or other similar container. Having added cement and sand and mixed everything thoroughly, all that remains is to pour in water in small portions and continue to knead the composition using available tools.
If you need to make a large volume of solution, it is recommended to use a special trough or bath. Here, blunt shovels or bayonet shovels, as well as choppers with a flat base. To simplify the process somewhat, experts advise performing the movements on yourself, otherwise your arms and lower back will get tired too quickly.
If you have a construction mixer, it greatly simplifies the work. The nozzle is any suitable element, be it a curved wire or a blade. Concrete mixers also make it easier to mix the solution, but their use is only advisable if the volume of plaster is very large.
Most reliable way, with the help of which you can qualitatively level the walls, this is plastering. Plaster allows you to prepare the base of external and internal walls for finishing. Previously, to prepare a solution for plastering walls with your own hands, classic ingredients were used, mixed with water in the correct proportion. It was only cement and sand.
The modern market for construction and finishing materials is full of ready-made mixtures that just need to be diluted with water. However, the rules for mixing the mortar will vary depending on the composition of the plaster. How do cement, clay and lime mortars differ from each other, and how to mix them correctly?
]The easiest way to have a beautiful front lawn
You've certainly seen the perfect lawn in a movie, on an alley, or perhaps on your neighbor's lawn. Those who have ever tried to grow a green area on their site will no doubt say that it is a huge amount of work. The lawn requires careful planting, care, fertilization, and watering. However, only inexperienced gardeners think this way; professionals have long known about the innovative product - liquid lawn AquaGrazz.
Plaster composition
Each plaster mortar has its own components, mixed in different proportions:
- clay and sand in a ratio of 1 to 2 (5) - the number of shares of sand depends on how viscous the clay is;
- a solution consisting of three components - clay, lime and sand - is mixed in a ratio of 1: 0.4: 4;
- plaster made of clay, cement and sand is mixed in a ratio of 1:0.3:4.
All listed species plasters are mixed with water, the amount of liquid directly depends on what viscosity you require.
What is required for work
To mix different plaster compositions, you will need one or more binders (cement, lime, clay or gypsum), a filler (usually sand) and water. When mixing all the ingredients, you should be guided by the exact ratio of the composition shares. However, this is not the only thing that needs to be taken into account: the quality of the plaster is influenced by such a thing as fat content. Most often this applies to lime and clay plasters.
In this case, the concept of “fat content” has nothing to do with its literal meaning: it is a parameter by which the amount of binder component is determined - sufficient or excessive. Based on fat content, plaster compositions are divided into three types - fatty, normal and thin.
- The disadvantage of greasy plaster is that it shrinks too much when drying, which leads to cracks on the surface.
- A solution that is too thin also becomes covered with cracks, but for a different reason - it does not adhere well to the surface and gradually begins to move away from the base.
It is difficult to determine the level of fat content of plaster by eye; this requires some experience. While mixing the composition, check how strongly the plaster sticks to the tool. The more the solution sticks, the fatter the plaster, but thin plaster, on the contrary, will stick very poorly or will not stick at all.
Cement mortar
To properly prepare a cement plaster composition, you need to perform several stages of work:
- First of all, the sand is dried and sifted until there is not a single lump left in it. Important: reddish sand should not be added to plaster, as it is of low quality. If you don't want to bother with sifting, you can use quarry sand, it is already clean and crumbly.
- The second and final stage is kneading. Pour cement and sand in a ratio of 1 to 4 into a container of a suitable size and mix thoroughly. To avoid the appearance of lumps, add water gradually. However, it will be extremely difficult to mix such plaster yourself if you need too much solution. For such volumes you will have to rent a concrete mixer.
Important: to obtain high quality plaster, you must use cement of at least M400. With the use of cheaper and low-quality cement, the walls will simply crumble.Lime mortar for walls
Making such plaster is somewhat more difficult than classic cement mortar. Lime plaster hardens much more slowly, so you will have to resort to some tricks.
Important: only slaked lime is suitable for preparing lime mortar.
Stages of work:- Grind the lime so that the end result is a homogeneous mass without lumps.
- Add sand in proportions of 3 to 1 to lime.
- Mix the dry plaster thoroughly and begin gradually adding water until you get a solution of the desired thickness. Finished plaster You should not store it for more than a day - it will be unsuitable for further use.
- To make lime plaster harden faster and have better adhesion, a little gypsum should be added to it. But in this case, it is better to stir the composition in small quantities, since it will harden very quickly - almost instantly after application.
Important: do not overdo it with the amount of water. Too much a large number of Liquids will only worsen the quality of the plaster.
Clay plaster mortar
No less often than lime and cement, natural clay is used. The main thing is that you should not buy liquid clay for plaster, because it will slide down from the wall over time. In order for the solution to be of high quality, you will need a large number of ingredients - clay, sand, cement and lime. Stages of preparation:
- Soak the clay with water for 6 hours and add regularly new water as soon as you see that upper layer began to dry out. The clay should be of medium thickness.
- Pour in pre-sifted or quarry sand in a ratio of 2 to 1. Sometimes the amount of sand needs to be increased to four parts.
- To strengthen the solution, add 0.2 parts of cement and mix well.
Not all plaster solutions are suitable for outdoor work; some are used only for finishing indoor walls. The technology for using mixtures depends on their composition.
Where is plaster used?
Depending on the climate, humidity level, and location of application of the plaster, different solutions are used:
- Lime and lime-gypsum plasters are best suited for leveling indoor surfaces. Such walls are literally “breathable” - depending on changes in humidity levels, they either store moisture or release it back. As a result, the microclimate in the room is constantly regulated and maintained at normal levels.
- Cement-sand plaster is used for external finishing works, and is also used in rooms with too much high humidity- in the kitchen, bathroom, bathhouse, etc. Such plaster not only levels the surface of the external walls, but also holds them together, making them stronger. Cement-sand mortars are used for finishing stone fences and garages.
- Pure lime plaster is well suited for treating window slopes; it is much more effective than cement plaster, since it has best parameters thermal insulation. For example: the thermal conductivity of lime plaster and cement plaster is 0.86 and 1.3, respectively.
- Clay plaster is often used to decorate stoves, pipes and fireplaces. In this case, the immediate space around the stove is plastered with a clay-sand composition, and the thermal surfaces are plastered with a solution of clay and lime.
Preparing the surface for plastering
Plaster of any type must be applied only to a previously prepared base, otherwise the results of the work will not please you - the plaster will fall off the wall or ceiling along with the decorative coating.
- IN brickwork it is necessary to remove all protrusions from the seams, and the bricks themselves must be completely cleaned of dust, dirt and cement residues.
- Before starting work, notches must be applied to the surface of the building blocks.
- If there was previously plaster on the base, it needs to be completely beaten off or only the top layer removed - depending on the condition of the coating.
Calculation of plaster consumption
Before starting work, it is important to know exactly how much plaster mortar is needed - this will help save money by avoiding waste of material. There are two main factors that are important to consider when calculating the volume of plaster:
- Curved walls. If it so happens that the walls in one room are different in length and width (and this is not uncommon, for example, in panel houses), they must be leveled, which will require a much larger amount of plaster mortar. You will also have to increase the volume of the mixture if there is a need to seal cracks and potholes.
- The composition of the plaster itself. Since different mixtures have their own consistency, the consumption per 1 sq. the meter will be different.
Plaster calculation method
First of all, you need to determine the required coating thickness. You should first prepare the base by removing all parts that are not firmly attached or are crumbling. When the wall is ready, use a laser level and determine the level by placing beacons around the perimeter of the room. If you don’t have a laser, use a weight (an ordinary washer will do) on a strong thread. Next, measure the degree of deviation from the resulting line at 4 points, add the resulting data and divide by 4.
Standard plaster mixtures are based on a layer of 1 cm per 1 square meter. meter. It is enough to calculate the area of the walls requiring plastering. Multiply the resulting dimensions by the average thickness of the plaster calculated earlier. At the same time, always buy mixtures with a small reserve, since the actual consumption of plaster may differ from what you calculated. Buy a couple more packs, but no more.
Some features of plaster mixtures:- The lime composition is warmer and practically not susceptible to the appearance of mold and fungi.
- Cement plasters are moisture resistant and have great strength.
- Gypsum in lime mortars increases their strength and quality of adhesion to the surface, but greatly reduces the time of use.
- Clay plaster mortars are the least durable of all, but they can withstand very high temperatures very well.
When carrying out finishing work, external or internal, be guided by the choice of plaster based on the highest priority qualities. Then the plaster will last a very long time, and over time there will be no surprises in the form of cracks or crumbling walls.
Plastering is a process that improves the quality of the treated coating and increases consumer properties accordingly. Thanks to today's material, you will learn how to mix mortar for plastering walls with your own hands. All proportions are given separately from the cooking technology. We will also consider a list of ready-made mixtures suitable for people without experience in such matters. Please share your feedback in the comments.
Ready-made mixtures for preparing mortar for plastering walls
No. 1. "Knauf Diamant"
Price – 340 rubles. Decorative plaster, which is a cement-based colored mixture. Acts as a filler quartz sand. The advantages include excellent water-repellent characteristics, as well as immunity to temperature changes and ultraviolet radiation. It is used both for the facade and for finishing walls inside the house. The proportions are such that for 25 kg. the mixture is supposed to be 7.5 liters. water. The prepared solution must be used within 2 hours maximum. Packaging in 25 kg bags.
No. 2. "UNIS»
Price – 280 rubles. An excellent option for finishing a room inside or outside. Among the advantages, we highlight the absence of shrinkage, resistance to moisture, pressure and temperature changes. The composition is distributed over the walls in a layer of 3 cm, and there is no need for reinforcement. You can make your own mortar for plastering walls, but it makes sense to purchase this mixture. The breeding proportions are as follows: per 10 kg. composition is supposed to be 1.6-2 liters. water. The solution must be used up within 2 hours. Packaging is carried out in 25 kg bags.
No. 3. "Prospectors"
Price – 190 rubles. Cheap composition for further dilution of the solution. It is made on the basis of cement, the final coating is strong. After distribution, the mixture does not shrink and there is no risk of cracks. As for the proportions, for 10 kg. dry composition accounts for 2.6-2.8 liters. water. After mixing, the solution must be used within 1.5-2 hours. Packaged in 25 kg bags.
No. 4. "Weber Vetonit»
Price – 360 rubles. Premium composition, cement plaster. Among the obvious advantages, it is worth highlighting the absence of shrinkage, the strength of the final coating, ease of application, resistance to moisture and changes temperature regime, as well as plasticity and product quality. When breeding, you should be guided by the proportions: per 10 kg. dry composition accounts for 2.5 liters. water. The solution must be applied within 3 hours; it will dry in 2-6 days.
No. 5. "Osnovit Flywell T-24"
Price – 240 rubles. If you need a solution for plastering walls on cement based, there is no point in doing it yourself. Consider this option. Pros: ease of application, resistance to moisture, frost and temperature changes. Proportions: for 10 kg. dry mixture accounts for 3-4 liters. water. On the shelves of construction supermarkets you will find them distributed in 25 kg bags.
Self-preparation of the solution - proportions
If you don’t have the funds to purchase a special mixture, you can make it yourself. We will present the proportions for lime and cement mortars, and below we will consider the mixing technology.
No. 1. Mortar
Before you make a lime mortar that is ideal for plaster, study the proportions:
- you will need to take lime and sand in a ratio of 1 to 3.
No. 2. Cement mortar
Since you can prepare a mortar for plastering walls from cement and sand, we present the ratio. The finished composition is distributed over the walls in three layers, each of them having its own proportions:
- 1 layer: 1 part cement to 3-4 parts sand.
- 2nd layer: 1 part cement requires 2-3 parts sand;
- 3rd layer: 1 part of cement is combined with 1.5-2 parts of sand.
Self-preparation technology
Now that we’ve figured out the ratio, let’s study the technology for mixing lime and cement mortars.
No. 1. Mortar
1. The composition is prepared long before the intended plastering of the walls. Take care of this 2-4 weeks in advance. If lime is properly slaked, it will be stored for a long time without loss of quality.
2. Do-it-yourself mortar for plastering walls is made after preparing the appropriate utensils. You have studied the proportions, now take a non-rusty metal container, plastic container not used.
Attention!
Quicklime is considered a toxic component, so make sure you have a mask and gloves in advance. Take care of your mucous membranes and skin to avoid burns.
3. Pour into a bowl lump lime(1 part), pour in cool water (2 parts). Mix the contents with a stick or shovel. This will speed up the hydration process. The duration of extinguishing can take up to half an hour. Everything will depend on the composition of the lime. As soon as the steam release decreases, stir everything again. Repeat several times.
4. When the reaction is completely completed, last time stir the grounds. Cover the container and leave for 12-14 days. Over the allotted time, the mass will become plastic. In addition, all lumps will disappear.
5. If you are going to carry out work on a large scale, you will have to dig a pit at least 1 m deep. Lime is poured into the hole. Next, you need to water it with water from a hose. As soon as chemical reaction stops, pour in an impressive layer of sand (in accordance with the proportions above). The pit must be covered with a wooden shield. After 2-4 weeks, the composition can be used for its intended purpose.
The solution for plastering walls is quite simple to make. It is enough to mix all the components with your own hands and wait the specified period. If you follow the proportions, you will end up with an elastic dough.
Cement mortar
To finish the facade or walls in a room, you can use cement mortar. The plaster will be applied in 3 layers. Let's look at everything in order.
Layer No. 1 – spray
1. Before preparing the cement mortar, you should know that the first layer will be a little liquid. This is necessary for plastering walls using this technology. The layer thickness should not exceed 4 mm. You will need 25 kg. cement grade M500.
2. Prepare a container of sufficient size and pour 6 buckets of sand into it (bucket volume 10 liters). Don't forget to sift it first. After this, add cement and mix everything thoroughly with a shovel.
4. Finally, pour in another 10 liters. water and stir the grounds thoroughly. Next you can apply plaster.
Layer No. 2 – ground
1. If you have made the cement mortar for plastering the walls and sprayed it yourself, proceed to the next step. Keep in mind that the second layer is distributed immediately after the first one has set. The cement mortar must not be allowed to harden completely.
2. When preparing the primer layer, observe all proportions. When applied, its thickness should not be more than 15 mm. When performing work, there is no need to use mesh for reinforcement. The second layer should be made of a mixture with a structure like stiff dough.
3. Pour 25 kg into a container. cement, keep in mind that you need to add 15 ml to each bucket. liquid soap. Next, add 5 buckets of sand (sift in advance). There will be enough water in quantities of up to 20 liters. Mix all ingredients in the same order as described. Apply.
Layer No. 3 – covering
1. To make the final layer, you need to purchase the finest sand. In addition, it must be as clean as possible. The thickness of the final layer should not be more than 3 mm.
3. If you use a concrete mixer, the mixing process is slightly different from manual mixing. Pour about 17 liters into the device’s container. water (total 25 liters required). After this, fill the bag of cement.
It is easy to understand that preparing a solution for plastering walls is quite simple. If you need large volumes, it is better to use a concrete mixer. In other cases, you can handle the task yourself. Don't forget to respect all proportions.
Plastering is an integral stage of finishing the surface of walls and ceilings. Except protective function it serves as decoration, increases fire resistance and acts as an additional insulator. In addition, plaster allows you to hide small surface defects and connecting seams. The strength and durability of the plaster layer directly depends on the correctly selected composition of the mixture.
Overview of types of plaster solutions
Before directly preparing the plaster mixture, it is important to assess the microclimate in the room. Thus, for finishing external walls, cement or cement-lime plaster is most often used; if the climate is quite dry, then lime plaster can also be used for finishing external walls. But in temperate climates it is most often used for interior spaces.
Depending on the purpose, the following types of plasters are distinguished:
- Cement. It is characterized by a slow set of strength; the mixture sets within 12 hours after introducing water into the mixture. It has the greatest strength compared to other types of plasters.
- Clay. Used for plastering wooden surfaces.
- Limestone. To speed up setting and give greater strength, building gypsum is sometimes added to the lime plaster solution.
- Gypsum can be used by itself. It must be remembered that the solution hardens completely after 30 minutes, and after 4 minutes setting begins.
- IN combined solution Several binders are used for plastering walls (cement and lime, lime and gypsum, etc.).
- Special plaster. Depending on the purpose, an appropriate additive is added to the mixture.
Sand is most often used as a filler. It is best to use river sand to prepare the plaster mixture. The sea one is characterized by excessive salinity, which affects the strength of the mixture, and the ravine one is, as a rule, too polluted.
Composition and proportions of mortar for plaster
To prepare the mixture you will need a binder, filler and water. In some cases, it is possible to use additives to impart the required qualities to the mixture. For example, in order to obtain a waterproof mixture, it is enough to add calcium nitrate to the usual components of cement plaster.
Since plaster is usually done in 3 layers, the composition of the mixture for each layer is different. For spraying, a mixture with a reduced binder content is used, to prepare the primer layer the binder content is slightly increased, and for the finishing layer the maximum permissible amount of binder is used. Thanks to this, the finishing layer is characterized by increased strength. If the plaster is performed in 1 layer, it is recommended to use the average of the proposed ratios of binder and filler. Otherwise, the mixture will not be flexible enough and may move away from the surface of the wall or ceiling.
Solutions for plastering walls have different compositions; it is recommended to use the following ratio of binder and filler:
- For cement plaster, the ratio of cement and binder is: for spraying - 1 part binder to 2.5 - 4 parts filler, for the primer layer per unit volume of binder there are 2-3 parts filler, and for the finishing layer - from 1.5 to 2 parts.
- The proportions of the solution for plastering walls using clay are unchanged for each layer - it is recommended to use 3-5 times more aggregate than clay.
- Lime mortar for plastering walls has the following composition: spray from 2.5 to 4 parts of filler to 1 part of binder, for the primer mixture - from 2 to 3 parts, in the finishing mixture it is recommended to use 1-2 parts of filler to 1 part of binder.
- Cement-lime mixture, for preparation per unit volume of cement there are: for spraying - from 0.3 to 0.5 parts of lime and 3 - 5 parts of filler, for a primer layer - from 0.7 to 1 part of lime and 2.5 - 4 parts of filler, for finishing the lime content increases to 1 - 1.5 parts, sand content does not exceed 2.5 - 4 parts.
- Lime-clay mixture: 0.2 parts lime and 1 part clay to 3 – 5 parts sand.
- The composition of the cement-clay mixture can be taken to be the same for all layers of plaster - 1: 4: 6-12 (cement: clay: sand).
- Lime-gypsum solution (lime: clay: sand), for 1 part of lime there is: spray -0.63-1 part clay and 2 - 3 parts sand, primer layer - 0.5-1.5 parts gypsum and 1.5 -2 parts sand, finishing layer – 1 - 1.5 parts gypsum (in this case, sand is not added).
Tools and materials for preparing plaster mortar
To prepare the plaster mortar you will need:
- Container for loading materials.
- Dispenser (any container for volumetric dispensing of materials);
- An attachment for a drill (mixer), which will be used to mix materials. Mixing can also be done manually using a trowel or any other available tool.
- Binder (lime, cement, clay, etc.).
- Filler (sand, sawdust, etc.).
- Water.
- Additives to give the mixture the necessary properties, such as water resistance.
Besides correct selection composition of each plaster mixture, on the quality of the plaster layer great attention the technology for preparing the mixture provides. At first glance, it may seem that there is nothing complicated in mixing the components, but this is not so. For each type of mixture, there is a recommended order for loading the components and mixing.
- It is recommended to mix the cement mortar in a dry state. First, sand is poured into the container and leveled until an even layer is obtained, cement is poured on top. These components are mixed dry and only then diluted with water and mixed again until a homogeneous solution is obtained. It is better if the layers of sand and cement alternate several times.
- In mixtures using lime, only slaked lime should be used. The filler is gradually introduced into the lime dough with the addition of water. This will avoid lumps and ensure a homogeneous mixture.
- If it is necessary to add gypsum to it, remember that it is allowed to spend no more than 2-5 minutes on preparing the solution. In this case, the gypsum dough is first prepared (plaster is poured into water and mixed until a homogeneous mass is obtained), then a lime solution is introduced into it.
- To prepare a clay plaster mixture, you need to soak the clay for a while and knead it to get rid of large lumps.
- When preparing cement-lime mortar, cement and sand are also mixed dry and then poured with lime milk until the desired consistency is obtained.
- In addition, pre-prepared dry mixes are available on the market. In this case, you just need to add the recommended amount of water to the mixture and stir until the desired consistency is obtained.
Compliance with all the rules for preparing a solution for plastering walls will allow you to achieve the required strength of the plaster layer and its durability. Ideal plaster besides direct functional purpose will also perform an aesthetic function.
Despite the rapid development construction industry and the emergence of new methods of finishing buildings and structures, none of the alternative finishing methods is still able to compete with traditional plastering of walls. This is due to the undoubted advantages of the method and its features, as well as the ability of plaster to create a protective finishing layer on the surface of the walls being treated, which helps level the surface and create a decorative cover. With the help of plaster you can pour the foundation for a building, build a wall or make it finishing, as well as eliminate existing errors - to carry out all these activities you need a plaster solution. However, for each of these directions, different types of plaster mortar are required - in the process of finishing work, lime mortar will be required for plaster, for wall laying - masonry mortar. And that's not all existing varieties plaster solutions. Construction stores offer consumers the opportunity to purchase ready-made mixtures for preparing plaster, surprising consumers with the variety of these products. In order not to doubt the quality of the solution, you can prepare it yourself, saving a significant amount of money. To get to the heart of the matter and get acquainted with various types plaster solutions and methods for their preparation - read our article.
- Preparing mortar for plaster: a step-by-step guide
What is plaster? Main Components
Plaster is a rough facing material used to level surfaces for various purposes - walls, ceilings, foundations. Depending on the style you choose for finishing the surface being treated, various components may be included in the plaster, however, regardless of the purpose of the plaster, the following components must be included in its composition:
- A binder that increases the adhesive characteristics of plaster and its fastening properties;
- A filler designed to relieve internal tension between particles of binding components, as well as to increase the volume of the solution;
- Water intended for soaking and mixing components solution. Craftsmen who do not have sufficient experience in this area do not have a clear idea of what the difference is between certain types of mortar for plastering walls, if they consist of the same fundamental components. In addition, there is often an opinion among amateurs that you can start work by mixing cement with sand and water. However, experts assure that it is far from so simple and offer you the following recommendations.
Depending on the purpose of the plaster, it is customary to add the following components to its composition, each of which plays a specific role and gives the solution additional characteristics:
Lime is added in cases where it is necessary to give the solution additional viscosity. The lime used to prepare the solution can be slaked or quicklime, ground or multi-colored. It is a fragile material with a long drying time, as a result of which lime mortars are used for finishing work exclusively in dry rooms;
Gypsum or alabaster also does not have significant strength, but is characterized high speed hardening. It is advisable to use this material for minor finishing activities and as an additional component to lime mortar, which will increase the speed of its drying;
Cement is a high-strength material that is resistant to atmospheric influences and retains its original characteristics after contact with water. Resistance to mechanical stress is another important advantage of cement. Plaster based cement-sand mortar used for external decoration of building walls, as well as surfaces located in areas of high humidity;
Clay is another component used as an additive to plaster mortar to increase its viscosity. Similar compositions are perfect choice for plastering and laying stoves, due to the fact that after firing, the solution, which contains clay, becomes as durable as possible;
Sand in the mortar for plaster is used as a filler, due to which the volume of the mixture increases. Various types of sand are used for mortars intended for different purposes, however the greatest efficiency has river sand, which is sorted and sifted before adding to the solution.
Main types of plaster solutions: proportions of ingredients
In accordance with the predominance of certain components, the following types of plaster solutions are distinguished:
- Lime mortar for plaster, to reduce the hardening time of which gypsum is sometimes used;
- Cement mortar for plaster, the preparation of which often does not raise unnecessary questions;
- Lime-cement mortar for plaster, which contains three components: lime paste, cement and sand;
- Lime-gypsum mortar for plaster, combining optimal viscosity and hardening speed;
- Clay mortar for plaster, to which some minor components can be added to give the mixture the necessary qualities.
Each of these plaster solutions has its own proportions, observing which you can create the optimal working mixture.
One of the most popular mixtures for finishing work is lime mortar, consisting of slaked lime, which is soaked in water, and sand. Ratio mass fractions these components look like 1: 2, less often 5;
Cement mortar for plaster consists of cement and sand, with a mass fraction ratio of 1: 3(4). To prepare the solution, the resulting dry mixture is poured with water;
To prepare a cement-lime mortar, you will need cement and sand, taken in a ratio of 1: 3(4), as well as a lime suspension, which is slaked lime diluted with water to the consistency of milk;
Lime-gypsum mortar for plaster is a regular lime mortar consisting of a mixture of sand and slaked lime, as well as gypsum. The ratio of the mixture of lime and sand to gypsum is 1:0.3;
Clay mortars for plaster are most often prepared with the addition of minor ingredients such as cement, sand, gypsum or lime. The choice of one or another component depends on the subsequent use of the solution. The approximate ratios of components in clay mortars for plaster are as follows:
- Clay and sand in a ratio of 1:2 (5), which depends on the viscosity of the clay;
- Clay, lime and sand in a ratio of 1: 0.3:4.
To prepare the solution, you will need to add water to the dry mixture, the volume of which depends on the required viscosity of the solution.
Important! Before preparing the solution, you need to make sure that it is necessary to use this particular mixture. For the greatest reliability, it is necessary to estimate physicochemical characteristics solution and place of their use. If the component composition is incorrectly selected, this may cause a decrease in the performance characteristics of the treated surface.
Thus, the choice of ingredients depends on:
- Type of work (solution for external plaster must be resistant to high humidity);
- External conditions under which the building or premises are operated. These include: temperature, humidity, the presence of aggressive external factors;
- The material from which the surface to be plastered is made.
Types of plaster depending on the proportion of ingredients:
Taking into account the proportions of the fundamental components plaster mortar can be divided into three types:
- A fatty solution in which the binding component predominates. After drying, such a solution is prone to cracks;
- A normal solution characterized by optimal ratio filler and binder;
- A thin solution, which is characterized by a small amount of filler, and therefore is short-lived and fragile.
To determine the type of mortar, all you need is a trowel and a little observation. Dip it into the solution and look:
- If the solution sticks to the trowel in chunks, the solution is greasy;
- If the trowel is only slightly dirty, the solution is thin;
- If the solution lays on the trowel in the form of a thin crust, the ratio of binder and filler is normal.
Important! You can reduce the fat content of a solution by adding a filler to it, while you can increase the viscosity of a lean solution by adding a binder.
Composition of plaster mortar: general requirements
What should you pay attention to when choosing the composition of a mortar for plaster? First of all, it is important to follow the following points:
- To plaster concrete and stone facades that are constantly exposed to moisture and precipitation, experts recommend using Portland cement and Portland slag cement to prepare a mortar for plaster;
- If stone and concrete facades are not constantly exposed to moisture, it is recommended to use solutions based on the use of lime and cement, as well as other lime-based binders, for plastering them;
- For finishing wooden and plaster surfaces, lime mortars are used, in which it is recommended to include alabaster to increase the rate of hardening of the mortar;
- Solution for interior plaster premises with high humidity(the humidity level during operation is above 60%, which is typical for a kitchen, bathroom or bathhouse), the first layer is applied from cement or cement-lime mortar.
Decorative characteristics of plaster mortar: what to look for?
Experts often recommend paying attention to decorative plaster solutions, which can be used both for interior decoration of room walls and for finishing facades. In the process of making decorative mortars, it is recommended to use the following substances as a binder:
- Traditional, white and colored Portland cement for finishing facades and interior walls;
- Gypsum and lime intended for colored plastering of indoor walls.
- In the process of making decorative mortars, the use of marble, granite, dolomite, tuff and various fractions of limestone is widely practiced;
Important! To enhance shine plaster composition, its composition contains no more than 10% crushed glass and 1% mica. It is also practiced to add dyes - alkali-resistant and light-resistant pigments of natural origin, such as chromium oxide, ultramarine, ocher, red lead and other known substances.
How to make mortar for plaster: preparatory activities
First of all, it is necessary to prepare a container for mixing the solution, the volume of which depends on the required amount of solution. Experts recommend giving preference to a container whose configuration will ensure a complete sample of the solution. If the container has a complex configuration, the solution will harden in the bottom and corners of the container, which will subsequently lead to difficulties in subsequent attempts to mix the solution. Experts recommend choosing containers with a large tray bottom; therefore, it is not recommended to use a bucket as a container for mixing the solution.
In addition to the container, you need to prepare following materials and tools:
- A dispenser, which can be used as any container of arbitrary volume;
- An attachment for a drill (the so-called mixer), designed for mixing the components of the solution. If you do not have a drill attachment, you can mix the solution manually using a trowel or other available tool;
- Binder (clay, lime or cement);
- Filler (sawdust or sand);
- Water.
Preparing mortar for plaster: a step-by-step guide
Before answering the question: “How to make a solution for plastering walls?”, it is necessary to answer that the preparation of the solution is carried out in several stages, the first of which involves preparing a dry working mixture, and the second – adding water to it and actually mixing the solution. There are two ways to prepare a solution for plaster: manual and mechanized.
Manual method of preparing plaster
It involves mixing the dry binder, during which the following rules must be observed:
- The first and most important requirement is the capacity requirement. Its bottom should be smooth and clean;
- Sand is poured onto the bottom of the container in the form of a continuous layer or in the form of small piles;
- The binder is distributed evenly over the sand layer;
- The mixture is mixed and leveled with a rake;
- The last two points must be repeated several times.
Important! If the mixture is not sufficiently mixed, its color will be characterized by heterogeneity and the presence of stripes, while the criterion for high-quality mixing of the composition will be its homogeneity.
Mechanized method of preparing plaster
To save time and effort, use a drill attachment or a so-called mixer to mix the solution. For a mechanized method of preparing mortar for plaster, the consumption of which largely depends on its composition and quality characteristics, you will also need a bucket or any container that replaces it. The necessary components are poured into it in the required proportions depending on the type of solution chosen and, using a mixer, mix it until a homogeneous consistency.
How to prepare cement-lime mortar for three-layer plaster?
Most often on construction sites The use of cement-lime mortar is practiced. They are intended for installation of external and internal three-layer plasters. To properly prepare such a solution, you need to know the requirements for the composition and consistency of each of the three layers, as well as their other specific features.
