Consumption of sand-cement mixture. Sand cement for floor screed

Sand-cement mixture for floor screed is today considered the most common and easiest way to level the floor and prepare it for laying the floor. To prepare a mixture for this solution, you do not need to be a professional, just follow the specified proportions - and you can do everything yourself.

The composition of the sand cement mixture

To understand how screeding occurs, it is important to understand what the substance consists of and what properties it has.

The components of the mixture are as follows:

• Portland cement is a special astringent that can be bought at a hardware store;
• fine filler (it can be imagined as sifted sand for construction);
• water (ordinary drinking water is perfect, you can even use spring or technical water);
• polymer fibers - are used to give the material more strength and prevent it from cracking in the future.

Depending on what ingredients this solution includes and what additives are there, the final characteristics of the resulting material may vary. There are several separate classes of sand-cement mixture, which differ in purpose and cost.

Light mixes

For work that does not require the use of a strong solution, the following brands are suitable:

1. Mixture M100. The composition includes carbonate lime and sea sand. This sand-cement mixture is intended for internal masonry and exterior work on masonry partitions and plastering walls. The price in this case is quite low, due to the small ratio of cement to sand and ranges from 105-150 rubles. per bag 50 kg.
2. Mixture M150. The material is universal, which can be used for decoration and repair work not only indoors, but also outside. Contains a larger amount of cement. Optimum cost in the ratio of quality and price: the price fork is 95-160 rubles. over 50 kg.
3. Mixture M200. In construction stores, it can be found in three variations: for plaster, for installation work and a universal option. This series is most often used for concreting floors or finishing light foundations. The cost of this brand is from 105 to 150 rubles. per bag.

Heavy mixes

To carry out work using a solution with a high cement content, you should take the following grades:

1. Mixture M300. Due to the increased content in the composition of high-quality cement, this mixture is a high quality material. It can even be used for the construction of heavy concrete walls and floor screed up to 15 mm without reinforcing mesh. The price of this type ranges from 105 to 160 rubles. over 50 kg.
2. Sand cement mixture M400. It includes special additives that not only increase the strength of concrete, but also make it resistant to cold. The price of this material is higher than that of other types, but the amount of concrete significantly exceeds the amount of sand. Due to its characteristics, this type of mixture is used for the construction of industrial structures (dams, airfields, bomb shelters). There is a foreign analogue of Z-40. The price of the M400 is from 195 to 205 rubles per bag.

What to look for?

Concrete mortar is always necessary for construction work, but it is difficult to make it right at the construction site. You can even make a mistake with the proportions, which will lead to a decrease in the quality of the resulting solution, and consequently, of all the work performed then. Therefore, special attention should be paid to the preparation of the mixture - in order to get the correct proportion, you must carefully follow the instructions. You can mix manually, but the work will go much faster if you do this with a concrete mixer or a special construction mixer. There is also the opportunity to purchase a ready-to-use solution.

With the correct preparation of the mortar, a strong and reliable building material with a long warranty period is always obtained.

Main advantages

Sand-cement mixture for floor screed has a number of pronounced advantages, which distinguishes it from other building materials:

1. This is the easiest to use semi-finished product. Just pour the right amount of substance with water and mix well. The result is a concrete solution of the desired quality. Dry mixtures are produced in special factories, where the proportions are strictly monitored. Moreover, it includes special additives that increase the quality of the material.
2. Such a mixture will significantly reduce labor costs, and construction work will take much less time. For this reason, dry material is very popular not only for screeding, but also for laying brick and even paving slabs.
3. If during construction it is necessary to save a little, then the best solution for this is a sand-cement mixture. The consumption of this solution is small compared to other materials, so its use is a great way to reduce costs.

Properties and features

Before you start working with a sand-cement mixture, you need to understand its properties well in order to avoid unforeseen situations in the future:

1. After the resulting solution has already hardened, you should pay attention to its color. It should be darker than regular concrete. If this is so, then you can be sure that everything is done correctly and that there are no errors in the amount of water when diluting dry material. Otherwise, the color of the resulting mixture will be either concrete or lighter.
2. Do not forget that cement stone is very sensitive to temperature extremes. It is for this reason that it is important not to forget about the damper gaps when pouring, otherwise the plate may just crack.
3. During the hardening process, you can notice a tendency that the plate moves up or down. Avoid its strong conjugation with neighboring walls - for a sand-cement mixture this is fraught with cracking.
4. When carrying out screeds, it is necessary to isolate the room from moisture. When the sand-cement mixture hardens, its structure becomes porous and can absorb moisture, and this categorically must not be allowed.

Sand-cement mixture: installation

You need to know that when installing a floor screed 1 mm thick, the consumption of the mixture per 1 m ² of floor area will be approximately 2.5 kg. The list of screed installation works will be as follows:

1. Before you begin screeding with a sand-cement mixture, you need to dismantle the old coating, cleaning it from dirt and sag.
2. Insulation. In order to avoid the penetration of dust and moisture onto the washed and cleaned surface, it is necessary to lay a waterproofing film by wrapping its edges against the walls by 5 cm.
3. Reinforcement. On top of the waterproofing material on the mounting legs is placed a frame of reinforcement or mesh.
4. Using a level, beacons are installed for laying a sand-cement mixture. You can buy or make them yourself.
5. Then proceed to the preparation of the solution. The dry mixture is diluted with water and stirred. By consistency, the resulting mass should look like thick sour cream.
6. The solution is poured onto the prepared surface and gently leveled. Care must be taken to ensure that no air bubbles form on the surface.
7. After drying - the time depends on the thickness of the screed - the surface is ground using a special construction tool.

GOST

To date, the most convenient and affordable building material that meets quality standards is a sand-cement mixture. GOST 28013-98 establishes the manufacturing rules and the percentage of the components used in dry sand cement mixtures. Also in this document are the main characteristics that a solution prepared from each specific dry mix should correspond to.