Aligning the walls inside and outside the room is a complex and time-consuming process. Moreover, the final result directly depends on the material used by the master. The building products market offers a wide range of plaster mixes. The most common are:
When choosing the right material, the functional characteristics of each type must be taken into account.
Calculations of material costs in the form of dry mixes.
At the very beginning of plastering work, a professional and an amateur needs to determine the amount of material required for successful work. A prerequisite for achieving quality end result is to adhere to all the features of the technological process. Calculations can be made using an example of such a parameter as the weight of dry plaster:
The average weight of one square meter of plaster is 15 kg on average. In order to find out more specifically, you need to multiply this weight by the thickness indicator. You can see an approximate calculation in the table below.
| Plaster thickness | Weight 1 m2 (kg) | Specific gravity (kg / m3) |
| 1 cm | 15 | 1500 |
| 2 cm | 30 | |
| 3 cm | 45 | |
| 4 cm | 60 | |
| 5 cm | 75 |
| Criterion / Plaster mortar | Gypsum | Lime | Cement |
| Vapor permeability | 0.11-0.14 mg / hPa | 0.10-0.12 mg / mhPa | 0.09 mg / hPa |
| Consumption for 1 m², with a thickness of 1 cm | 8.5-10 kg | 12-20 kg | |
| Working time of hardening | 1,5 hour | 2 hours | |
| Working conditions | it is necessary to maintain optimal conditions | resistant to water and air | |
| The need for puttying | absent | necessarily | |
| Moisture resistance | No | is present | |
| Bactericidal properties | does not have | It has | |
| Strength | high | not high | |
| Versatility (external and external facades) | No | universal | |
Based on the above data, we can say that all types of solutions have a number of advantages. They perfectly allow moisture to pass through without creating a “steam room” effect. In the process of work, there are also some nuances, for example - gypsum will have to be mixed more often in small portions, because it dries faster. Cement plaster can add heat capacity to the room, which is a significant advantage. When working in damp rooms, it is necessary to use a moisture-resistant solution.
As for the cost, it varies depending on the material consumption. So, the specific gravity of cement-based plaster is 2 times more than gypsum, respectively, the weight of 1 m2 plaster will differ. The price of gypsum mortar is higher, which means that there will be no special difference in cost compared to the cement-sand mixture.
When performing repair work on your own, you need to be able to correctly calculate the consumption of building materials. This will help you save money when buying them. The consumption of cement per 1 m2 of plaster depends on the quality of the surface on which we will apply the solution, the technical characteristics of the mixture and the texture of the resulting coating.
Let's consider how to independently determine the consumption of the mixture, depending on the thickness of the layer and the type of plaster used.
Types of cement mortars for plaster
Plaster mixes used for wall decoration differ in the presence of certain components and their ratio. Subdivided into types:
| Mixture type | Specifications | Proportions |
|---|---|---|
| Cement - sand | Used for rough interior and exterior finishing, the result is a durable, moisture-resistant coating. Suitable for finishing walls, ceilings in unheated, damp rooms and for cladding facades. The constituent components are cement and various fillers: sand, plasticizers, etc. | A standard solution is prepared in a 1: 3 ratio of sand and cement. Cement M 400 can be diluted 1 part to 8 parts of sand. M 100 is mixed in a 1: 2 ratio. The composition is selected depending on the type of surface, layer thickness, operating conditions. To increase plasticity, add PVA glue to the finished mixture in a ratio of 50-100 ml per 10 liters of the finished solution. |
| Cement - lime | They have good adhesion to all types of surfaces. They are used for finishing plinths, cornices made of stone and wood. Lime has bactericidal properties, protects the surface from mold and fungal infections. | 1 part of cement and lime to 5 parts of sand. For a 25 kg bag of cement we take 21 kg of lime, 280 kg of sand, 50 liters of water. |
The cement composition is most often used for rough wall decoration. A thin layer cracks during operation, therefore, it is recommended to apply cement-sand mortars with a thickness of 3 to 6 cm, depending on the material from which the walls are made and the applied plastering technology.
What affects the consumption of materials
The amount of mortar depends on the degree of alignment of the walls. The more defects, the more mixture will be required. The consumption of cement for plastering walls can be easily calculated by yourself. Consumption is determined based on the following components:
- type of solution and its components;
- how smooth the walls are, and what material they are built from.
In multi-storey buildings, the level deviation of the plane is 2-2.5 cm. The greater the unevenness of the surface, the thicker the layer will have to be applied.
To reduce, the surface is treated with a primer in several layers. It helps to dedust the surface, reduce the absorbency and better adhesion of materials.
At the junction of two surfaces made of different materials, we mount a construction mesh. Because of this, a thicker layer of plaster is required. produced according to a special technique.
In the houses of the old building, you can find perfectly flat walls, but more often the walls in them are crooked.
We calculate the thickness of the layer
We determine the difference in the surface relative to the vertical plane using a plumb line or installing beacons.
Ways to determine the curvature of walls:
- We lower the plumb line from the ceiling, find the most protruding point of the wall, then measure the depth of the depressions.
- we use long, even slats as beacons; we apply them to the wall, and we see how crooked it is; we measure the hollows on the wall.
For clarity, we will give an example of calculating the thickness of a layer of cement plaster for a wall with an area of 12 sq. m.
We add up the depth indicators of the cavities on the walls and divide the result by the number of beacons: (2 + 3 + 4 + 5): 4 = 3.5 cm.The thickness of the plaster layer will be equal to 3.5 cm.
Standard Consumption Rates
One bag 25 kg The average is indicated on the package, taking into account the layer of 10 mm, is individual for each manufacturer. If we apply the solution with a thickness of 2 cm, then we multiply the quantity by 2, etc. For plaster, the average consumption is 8.5 kg per square meter.
If we take a bag of 25 kg, then 8.5: 25 = 0.34% of the amount of the bag will disperse the plaster per 1 m2.
Let us consider in the table the calculation of the consumption of cement for plastering walls, depending on the thickness of the applied layer at a standard consumption rate of 8.5 kg per sq. m:
Marble chips impart a relief to the "Bark beetle" mixture Composition for finishing plaster The bark beetle contains marble chips, thanks to which a relief surface with an interesting structure is obtained. Standard consumption ranges from 2.5 to 4 kg. Each manufacturer indicates these indicators on the label.
Venetian plaster is applied in a layer of several millimeters, due to this, a small consumption of the mixture is obtained from 70 to 200 grams per square meter. m. Working with such material requires experience, in order to apply it to the surface with high quality, it is better to invite a professional.
Gypsum compositions are consumed in a ratio of 9 kg per sq. m. on our website will help you quickly calculate how much of this material is needed for finishing work.
When buying a plaster mixture, you need to add 10% to the estimated amount of material so that you do not have to run to the store during the work.
Plastering with our own hands
Apply three coats of plaster After calculating the required amount of material and purchasing dry components, we proceed to work.
Step-by-step instruction:
- Preparing the surface. We clean the wall from dust and flaking building materials. We clean out rust and oil stains.
- We prime the surface in 2-3 layers, each subsequent layer is applied after the previous one has dried.
- Apply the plaster in three layers. First of all, we spray a solution of medium consistency on the wall, this can be done with your hands, with a spatula, or thrown from a ladle. Then we grind the composition over the surface with a rule or a trowel: apply 4-5 mm thick on a concrete surface, up to 7 mm on a brick surface, and up to 10 mm on wood.
- The second layer is the main one. We knead the solution a little thicker than for spraying. With a spatula or trowel, apply the composition to the wall and rub it over the surface, level it.
- The last layer is applied with a thickness of no more than 4 mm, for which we prepare a more liquid solution. Apply a cover on the moistened base coat. After setting, but before the surface is dry, grout. For more details, see this video:
A variety of wall plastering is finishing on beacons, which allow you to create a perfectly flat surface.
The guides are set strictly in level at a distance slightly less from each other than the width of the rule. Lighthouses can remain in the wall or be removable.
Lead the rule from the bottom up Stages of plastering lighthouses:
- Fill the area between the lighthouses with a solution, level it using the rule. We fill in all the voids and carefully level them.
- We carry out a cover, we rub the surface well.
It is necessary to prepare such a volume of the solution, which we will have time to apply before it solidifies.
Be sure to study the calculations of the plaster consumption before starting work. Repair is not complete without leveling the walls and performing plastering work. The cement-treated surface serves as a reliable base for the finish.
In order not to be mistaken when purchasing materials for self-repair or to control builders, you need to know how much material is consumed. After studying this article, you can easily calculate these indicators.
The pace of construction also depends on the correct calculation of the required number of building materials. And if, for example, it does not cause any particular difficulties, then determining the consumption of cement per cube of solution can create certain difficulties.
How much cement is needed per cube of mortar - what will be the consumption?
Determining how much cement is in a cube of mortar is quite simple. To do this, you need to know the ratio of aggregate and binder, as well as the density of the cement (it is 1300 kg / m 3). If the ratio of binder and aggregate is 1: 4, then in the composition of the mortar mixture will be 20% cement... Given its density, cement consumption per cube of mortar will be 1300/5 = 260 kg (5 with a small bags)... The calculation of the required amount of binder can also be performed using special online calculators.
It is important to remember that the ratio of binder and aggregate is indicated in volumetric form, when calculating the number of bags of cement, these values must be converted into kilograms, taking into account the density of the material.
The easiest way is to determine how much cement will go to the cube of the foundation mortar. To do this, you just need to calculate the total volume of the foundation (in m 3). Then determine the amount of binder required to prepare a cube of concrete and calculate the total need for cement.
If it is necessary to determine the amount of cement for laying walls, the task becomes more complicated, since it is necessary to take into account the thickness of the mortar joint when calculating. To simplify the calculations, use the average consumption of the solution for the cube of masonry. Practice has shown that about 0.25 - 0.3 m 3 of solution is consumed per cube of masonry... Therefore, when determining how much cement falls on a cube of masonry, you first need to determine the volume of the walls of the building.
It has been experimentally confirmed that the amount of mortar per 1 m 3 of facing ceramic bricks is 13% higher than the required amount of mortar for laying other types of bricks.
The entire construction as a whole depends on the correct calculation of the required amount of binder. In the event of an error, the construction process can be stalled at the most crucial moment.
What affects the consumption of cement in the manufacture of mortar
When choosing the composition of the mixture, it must be remembered that with the growth of the cement grade, the need for binder decreases. In some cases, in order to preserve the structure of the solution after setting, stone dust is introduced into it.
Cement consumption per cube of mortar depends on:
- type of solution... Depending on the purpose in construction, sand, lime and clay solutions can be used. For each of these solutions, the ratio of binder and aggregate is different. So, in order to prepare a cement-sand mortar, cement and sand are taken in a ratio of 1: 3, 1: 4. For lime - cement is introduced in a ratio of 1: 3 to the lime mortar. When using clay, the consumption of cement per cube of mortar is entered on the basis of 1: 9;
- (determines the strength of the hardened mixture). The brand of mortar is chosen depending on which element of the building it will be used in. For the foundation and load-bearing walls, the strength of the masonry is of decisive importance, therefore it is recommended to use the most durable mortars. For interior walls, mixes with less cement consumption can be used. For plastering walls, you can use mixtures with a lower cement content;
- solution composition- the selected ratio of binder and aggregate.
There is a direct relationship between the brand of mortar and the content of cement in the mixture. The grade of the solution, depending on the content of cement in the mixture, is given in the table.
| Solution grade |
in solution, kg |
| M10 | 81 |
| M25 | 133 |
| M50 | 178 |
| M75 | 245 |
| M100 | 306 |
| M150 | 414 |
| M200 | 510 |
The values given in the table for the content of cement in the mixture are valid for 1 m 3 of the solution.
Depending on the required brand of mortar, the classes of cements used, as well as the ratio of binder and aggregate, differ.
Plastering walls and ceilings is an important stage in finishing work. The facing coating performs the functions of protection, decoration and additional insulation, perfectly hides seam joints and corrects minor masonry defects. The strength and durability depends on the correct ratio of the mortar components.
The basic composition of any plaster always remains unchanged: binder, aggregate and water. The choice of binder depends on the nature of the finishing work (external / internal) and the operating conditions (wet / dry microclimate). It can be cement, clay, lime, gypsum. Quarry or river sand is most often used as a filler. Sawdust, perlite, fine slag, granular polystyrene are less common. The filler provides strength and smoothness to the layer.
In practice, cement mortars are most often chosen for finishing external and internal walls; they are distinguished by increased strength and durability. A technological feature is delayed (about 12 hours) setting. To change the quality characteristics, it is combined with other binders. The proportions of the main elements in the composition of the plaster determine its performance.
- Fill in the previously sifted dry sand.To clean it of pebbles and shells, you need to use a fine mesh sieve. For priming walls, a diameter of 2-3 mm is suitable, for finishing - no more than 1 mm.
- Add cement and mix everything thoroughly. It is very important that the sand is well dried, then it evenly combines with the cement, does not burden it and does not allow the formation of lumps.
- Pour in water. First, add no more than 2/3 of the total volume. Pour the remainder gradually, achieving a homogeneous mass.
The ready-made solution must be used within an hour. Left unused, it begins to harden. If you add more water, you can restore elasticity, but the quality will be worse.
2. Cement-lime plaster.
It can be prepared in two ways:
- Mix lime dough with sand and add cement to it. While stirring constantly, pour in a little water until the desired consistency.
- Cement and dry sand. Prepare milk of lime by combining water with lime dough in a 1: 1 ratio. Dilute the sand-cement mixture with milk.
3. Cement-clay.
- Soak lumps of clay with water and cover them with a thick cloth.
- Mix the swollen clay with sawdust in a ratio of 1: 3.
- By adding water little by little, bring to the required density.
- To enhance the strength, add dry cement to the composition and mix thoroughly.
Solution consumption
The smaller the building elements, the more seam joints in the masonry. This directly affects the unevenness of the walls. Deviations from the level can be both vertically and horizontally. It will take a lot of composition to smooth out strongly curved surfaces. To calculate its consumption per 1 sq. M., You need to multiply the thickness of the layer and the area of the walls.
It is convenient to use a beacon to obtain curvature data. In this case, the minimum plaster thickness is 6 mm. This slightly increases consumption, but all surfaces acquire an ideal level.
To find out the maximum value of the curvature, it is necessary to hang the walls in several places. The more measurements, the more accurate the calculations will be. For example, deviations of 10, 15 and 40 mm were found. These parameters need to be added, and the amount divided by the number of measurements: (10 + 15 + 40) / 3 = 22 mm. The result is an average plaster thickness. Now it remains to multiply it by the area of the working surface.
In one cube of solution (in 1 m3 of solution) 2000 - 2200 kilograms (kg).For those developers who prefer to use a ready-made solution in a dry form, it is easier to make calculations. On the back of the packaging, manufacturers themselves indicate the exact consumption of material. With a layer thickness of 10 mm, approximately 10 kg of mixture per square wall is required.
One kilogram of solution contains 0.0005 - 0.00045 cubic meters.
To convert kilograms (kg) to cubes and vice versa, use.
How is the calculation done:
The calculation is made according to a simple physical formula Mass = Density * Volume.
The density of the solution depends on the type of solution and ranges from 2000 to 2200 kg / m3.
Hence:
1) If it is necessary to determine the mass of the solution, then multiply the density of the solution by its volume.
2) If it is necessary to determine the volume of the solution, then divide the mass of the solution by its density.
Theory:
The theoretical and practical concepts of converting one unit of measurement to another are based on the centuries-old experience of scientific research of mankind in applied fields of knowledge.
Mass is a characteristic of a body, which is a measure of the gravitational interaction with other bodies.
Volume is the amount of space occupied by a body or substance.
Density is a physical quantity defined as the ratio of body mass to the volume occupied by this body.
Practice:
This page provides the simplest answer to the question of how many kilograms (kg) in a cube (m3) of a solution and vice versa. One cube of solution is equal to 2000 - 2200 kilograms (kg). One kilogram of mortar is equal to 0.0005 - 0.00045 cubic meters.