How to calculate plaster consumption correctly

Kuleshova Christina

The correct calculation of the consumption of the stucco mixture saves working time during the repair by yourself. If the home foreman purchased an insufficient amount of dry plaster before finishing, a forced delay will occur during the work. You will have to buy up the missing amount of material, spend time on a trip to the store and additional money for delivery. Incorrect calculation in the direction of a large excess also creates annoying interference to the master. 3-5 unclaimed bags take up space, and it is not always possible to compensate for material costs.

In order not to make a mistake when calculating consumption rates, consider all factors and make accurate measurements. How to correctly calculate the consumption of plaster, prompt photos and videos in this article.

Cement plaster

Cement Plaster: Compositions and Applications

For plastering walls, cement mixtures of various component composition are used. Depending on the volume and ratio of ingredients, the purpose of the material is determined.

Cement-sand based plaster mix

Area of ​​use - rough finish of interior interiors (including with high humidity), ceilings, facades. Composition: cement and filler (sand, plasticizer).

Characteristics:

• strength;
• moisture resistance;
• keeping low temperatures.

Recommended recipe: cement + sand in a ratio of 1: 3 (for brand M 400 - 1: 8, for brand M 100 - 1: 2).

Cement-lime based plaster mix

The scope is the decoration of wooden and stone cornices, building socles.

Composition: cement, sand and lime.

Characteristics:

• moisture resistance;
• bactericidal activity;
• universal combination with any surface;
• protection of a basis against mold fungi.

Recommended recipe: cement + lime + sand in a ratio of 1: 1: 5. When finishing work on 25 kilograms of cement, 280 kg of sand, 50 l of water and 25 kg of lime will be needed.

Lighthouse installation

What factors affect the consumption of materials

Cement consumption per 1 m² of plaster is determined depending on the following factors:

• coating texture;
• the degree of destruction of the surface;
• rate of vertical deviation;
• technical characteristics of cement mortar;
• component composition of the mixture;
• wall material;
• base properties (adhesion, absorbency);
• method of applying the mixture.

The total cost is affected by the working area of ​​the walls and the price of the material. The manufacturer's instructions on the packaging recommend the ratio of dry matter to liquid, cement plaster consumption per 1m2.

Determination of layer thickness

The consumption of plaster per square meter increases due to significant deviations of the wall plane from the vertical axis. To align strictly according to the plumb line, the solution is applied to the base with a thick layer. Deep potholes and cracks increase the consumption of plaster per m2 in problem areas of the walls. Therefore, before calculating the required amount of material, the first stage of work is carried out - the determination of surface drops and layer thickness.

This work is not difficult for a novice master, but requires the accuracy of measurements and the use of special tools.

The curvature of the wall surface is determined by the method of installing beacons:

1. Lower the plumb line from the ceiling, find the area with the most protruding surface.
2. Mark the highest point on the ledge.
3. Measure the depth of the potholes and troughs, write down the results and proceed to set the beacons.

Important! The more vertical rails mounted on the wall, the higher the accuracy of the calculation of curvature.

Calculation example

Before calculating the consumption of plaster on a wall with an area of ​​12 m2, we determine the thickness of the layer. For this, 4 vertical beacons were installed and measurements were taken at four points. The parameters of planar deviations are 2, 3, 4 and 5 cm. We proceed to the calculations according to the formula: the total value of the depth of the troughs divided by the number of vertical bars. In this case, it turns out 14: 4 = 3.5 cm. This is the desired thickness of the plaster layer.

Cement mixes: typical consumption per m2 of plaster

Manufacturers of cement-based plaster mixes indicate on the factory packaging the average consumption rates for laying a centimeter layer. A typical commodity packing is a bag of multilayer paper weighing 25 kg. In this packaging, popular brands are widely represented on sale:

• Ceresit (CR 61, CT 29, CT 24);
• Founder (Bigwell T-22, Startwell T-21, Slimwell T-23);
• Prospectors (cement-sand, universal, Mixter);
• Knauf (Adhesive, Zokelputts UP 310, Grunband, Unterputts UP-210);
• Volma (Aquaplast, Aquasloy, Base);
• Weber Vetonit (TT, TTT);
• Hercules (cement-sand).

The rate of consumption of cement per 1 m2 of plaster:

• CeresitCR 61 - 0.9 kg for a layer of 1 mm;
• CeresitCT 29 - 1.5 kg for a layer of 1 mm;
• FoundersStartwell T-21 - 1.8 kg for a layer of 1 mm;
• Prospectors universal mixture - 1.3 kg for a layer of 1 mm;
• Knauf Grünband - 1.2 kg for a layer of 1 mm;
• Volma Aquaplast - 1.6 kg for a layer of 1 mm.

For each manufacturer and for certain types of dry mixes - an individual rate of consumption of plaster per 1 m2. Read the information on the packaging and multiply the numerical value by the thickness of the layer.

Important! The average consumption of cement-sand mixture is 17 kg per square meter with a layer thickness of 1 cm. It is advisable to buy material with a 10% margin, since in practice there is a significant over consumption of the mixture.

How to save material costs

Machine-assisted plastering helps to save mortar when decorating walls on large objects. If the surface area of ​​the walls exceeds 900 m2, it is cost-effective and cost-effective to buy a special apparatus. When decorating the walls in a standard-size apartment, it is more convenient to rent a stucco machine for rent for one-time use. Before calculating the consumption of plaster for manual application, analyze the automated version.This will reduce the cost of the mortar and significantly reduce the time of work.

In the process of mixing the cement mixture, air is introduced into the solution, and the plaster increases in volume. The consumption rate of plaster per 1 m2 with a machine application method is 9 kg. After drying, the surface does not require additional preparation for finishing. Mechanized plastering of a one-room apartment takes no more than half an hour.

Machine plaster

Tips & Tricks

1. To reduce the consumption per square meter plaster several times, apply a clean surface to the primer. Between layers, take breaks until completely dry. This will improve adhesion, reduce absorbency, dedust the base.
2. If the walls are made of combined materials, install a mesh at the joints. This will increase the consumption of plaster per square meter due to the thickness of the layer, but will hide the difference and strengthen the connection of dissimilar structures.
3. Add 100 ml of PVA glue to the finished cement mortar with a volume of 10 liters, and the plasticity of the mixture will increase.

The video shows how to plaster with cement mortar.