Sand-cement floor screed is by far 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 indicated proportions - and you can do everything yourself.
Composition of the sand-cement mixture
To understand how a floor screed 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 binder 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 - used to give the material more strength and prevent future cracking.
Depending ondepending 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 mortar, the following brands are suitable:
- Mix M100. The composition includes carbonate lime and sea sand. This sand-cement mixture is intended for interior masonry and exterior work on laying 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.
- Mix M150. The material is universal, which can be used for finishing and repair work not only indoors, but also outside. Contains more cement. The optimal cost in terms of quality and price: the price fork is 95-160 rubles. for 50 kg.
- Mix M200. In construction stores, it can be found in three variations: for plaster, for installation work and a universal version. 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
For the production of work using a solution with a high content of cement, the following grades should be taken:
- Mix M300. Due to the high content of high-quality cement in the composition, this mixture is a high quality material. It can even be used for the construction of heavy concrete walls and floor screeds up to 15 mm without reinforcing mesh. The price of this species ranges from 105 to 160 rubles. for 50 kg.
- Sand-cement mixture M400. It includes special additives in its composition, which 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 largely 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 the Z-40. The price of M400 is from 195 to 205 rubles per bag.
What to look out for?
Concrete mortar is always necessary for construction work, but it is difficult to make it right on 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 done afterwards. Therefore, special attention should be paid to the preparation of the mixture - in order for the proportion to be correct, you must carefully follow the instructions. You can mix by hand, but the work will go much faster if you do it with a concrete mixer or a special construction mixer. It is also possible to purchase a ready-to-use solution.
With proper preparation of the solution, you always get a strong andreliable building material with a long warranty.
Key Benefits
Sand-cement mix for floor screed has a number of distinct advantages, which distinguishes it from other building materials:
- This is the easiest semi-finished product to use. Simply pour the right amount of the substance with water and mix well. The result is a concrete solution of the desired quality. Dry mixes are produced in special factories, where proportions are strictly monitored. Moreover, it includes special additives that improve the quality of the material.
- This mixture will significantly reduce labor costs, and it will also take much less time to carry out construction work. It is for this reason that dry material is very popular not only for floor screed, but also for laying bricks and even paving slabs.
- If you need to save a little during construction, then the best way out 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:
- After the resulting solution has already hardened, you should pay attention to its color. It should be darker than regular concrete. If everything is so, then you can be sure that everything is done correctly and noerrors in the amount of water when diluting dry material. Otherwise, the color of the resulting mixture will be like that of concrete or lighter.
- Do not forget that the cement stone is very sensitive to temperature changes. It is for this reason that it is important not to forget about damper gaps when pouring, otherwise the slab may simply crack.
- During the solidification process, a tendency can be noticed that the plate moves up or down. Its strong mating with adjacent walls should be avoided - for a sand-cement mixture, this is fraught with cracking.
- When carrying out the screed, it is necessary to isolate the room from moisture penetration. When the sand-cement mixture hardens, its structure becomes porous and can absorb moisture, and this should absolutely not be allowed.
Sand-cement mixture: installation
You need to know that when installing a floor screed with a thickness of 1 mm, the mixture consumption per 1 m2 floor area will be approximately 2.5 kg. The list of works on the installation of the screed will be as follows:
- Before you start screeding the floor with a sand-cement mixture, you need to dismantle the old coating, cleaning it of dirt and sagging.
- Insulation. To prevent the penetration of dust and moisture on the washed and cleaned surface, you need to lay a waterproofing film, wrapping its edges against the walls by 5 cm.
- Reinforcement. A rebar frame or mesh is placed on top of the waterproofing material on the mounting legs.
- Using a level, laying beacons are installedsand-cement mixture. You can buy them or make your own.
- Next, start preparing the solution. The dry mixture is diluted with water and stirred. The consistency of the resulting mass should be like thick sour cream.
- 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.
- After drying - the time depends on the thickness of the screed - the surface is sanded with 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 rules for manufacturing and the percentage of components used in dry sand-cement mixtures. Also in this document are the main characteristics that a solution prepared from each specific dry mix must comply with.
