There are several embodiments of the cement-sand screed. The most popular of the available - filling semi-ties. This is a more versatile way device "rough" sex. No knowledge is not required when performing the installation, but some features worth exploring.
Advantages of semi-dry screeds
To begin to focus on the positive qualities of semi-dry screeds, among which:
- Cheap to purchase materials, which give a very high quality and at the same time an even semi-dry screed.
- No additional surface leveling subfloors, and is immediately ready for any chosen decking flooring.
- Performance time is reduced through the use of dry mixes, Food which usually takes place outside the venue installation. The solution is delivered via a pump, used in the.
- The process of feeding the solution to the site of future floor must not be interrupted. But it helps to lie quality solution evenly over the entire surface, virtually flawless.
- Small quantity of water used, that eliminates the possibility of leakage of the prepared solution on floors, below the. Shrinkage and virtually no, if it complied with the technology of the work.
- excellent heat, noise and sound quality.
- wearing qualities, that achieved through the use and addition of fiberglass.
there is, of course, and disadvantages, facing generally in the case, when disturbed phasing of work, proportions not kneaded mortar for floor screeds, fills are not on technology.
The choice of thickness
Pouring semi screed provides a choice of suitable thickness of the finished "pie". Minimal its parameters, as well as the maximum, you should consider pre, so that in the future to calculate the necessary amount of material.
The thickness of the cast floor will depend on the base, where there is a solution laying. The more evenly it is obtained, the smaller the amount of mixture required for. Despite, that semi-dry screed floor and so gives a small load on the overlap, weight must be considered when determining the thickness. She screed in this case must withstand a certain load (constant walking, the presence of large pieces of furniture, household appliances, etc.). 
Under tie layer may be positioned and hydro insulation, communication pipe, backsheets. Their presence or absence and have their say on the question of, a perfuse floor thickness. Particular importance should be given to the warm floor regardless of the particular embodiment: water or electric. All these elements should be covered with a semi-dry screed. In addition, the flooring needs to go to a specific version of the "rough" sex.
There is a huge caveat in the semi-dry screeds, that there is no adhesion of the overlapping, a base directly - Polyethylene film, serving as the waterproofing layer. For this reason, the semi-dry screed must be performed by the minimum thickness 40 mm. If the base serves as a concrete block or, such as foam, the general 50 mm.
Underfloor heating brings about changes, because it must be completely covered by the screed. semi-dry screed floor in such a case must cover all the elements of at least 35 mm. When the device with electrical floor heating except in thickness 40-50 mm, must be a layer of litter - thermally. No harm will be used as an additive plasticiser, contributing to minimize the appearance of cracks and chipping on the surface.
In any work should be guided by special regulations, which include building codes 2.03.13-88. Directly in step 5 are the minimum requirements for the screed.
If you are polusuhaya screed in several areas, then its thickness may vary depending on the flooring. 
In this case, it would be better to perform multilevel screed.
When it is said about the semi embodiment subfloor device and its maximum thickness, it is not limited. The average values are equal 5-12 cm.
But it is worth noting, it affects, as semi-dry drying floor screed. The greater the thickness, the long period of time will have to wait until the deck flooring. Any finishing operation can not be performed on a wet screed. Otherwise be prepared to negative consequences.
Preparing the solution
Prior to installation of important to prepare the solution for. It consists of a special construction mixtures, to which have been added special ingredients to improve the quality. The solution may be prepared independently, mixing between a cement, sand, water, do not forget about the reinforcing agent. As the latter is most often used fibrovolokno, which gives excellent quality of the finished solution plasticity and strength. 
Should get a homogeneous solution, without komkov. This will allow eventually fill truly flat floor. All of the large lumps are broken down as far as possible. Only after this is done pouring the floor screed semi.
The whole area is filled evenly, Doing breaks. Leveling of the solution is performed by using rule. In the following will only make the grout surface and leave for some time to dry.
Jobs in the winter
When starting repair work in the winter time, many people think that, at what temperature can be poured floors. Here it is necessary to take into account the time, sand that starts at subzero temperatures below -10 degrees regedit in lumps. This makes it virtually impossible for kneading a full solution. If we just needed screed winter, then there are two options:
- Wait until the temperature rises to -2 degrees.
- To arrange a heated room for mixing solution. true, This option is more suitable for private homeownership.
The increase in the cost of the material will cause the acquisition antifreeze additives. But in the end it will not allow solution regedit, it will be possible to perform the installation. 
In certain finished building dry mixes the additive is already available. It remains only to prepare a solution.
In winter, you can fill in a semi-dry screed with the help of another folk remedy - add a few drops of detergent. This will facilitate the process of delivering the solution to the high floors located in an apartment house. Sami hoses is not superfluous to insulate various options, which will be more profitable.
At what temperature can be made semi-dry screed indoors? The minimum temperature in this case should not fall below +5 degrees. Otherwise filled solution can not be fully dry before further handling. This indicates, that still can be poured floors winter.
drying time
Semi-dry screed according to German technology dries instantly, within a few days. After that can perform decking flooring. But it is worth noting, that every concrete finished floor execution requires some time to dry completely.
Tile period is extended due to the fact, that will use a special glue for installation. If you leave the "rough" sex raw, the adhesive does not come to grips, which will lead to peeling tiles. Average figures are drying 14 days. 
But much will depend on the thickness of the subfloor. It is important to know, how much should dry screed before laying laminate. The floor covering should not be subjected to excessive moisture, but always stay dry.
When the thickness of the screed in 60-70 mm, for complete drying screed will take about three weeks, and four weeks will have to wait, to a dried coating 10 cm. It is worth noting, that almost any coating method on the expiration semidry 12 hours after installation you can walk, perform finishing the event in the room. This is not to exert pressure on him from the outside.
If deadlines are not running out, it is best to leave the "rough" sex for a longer period, that all excess moisture came out. Then will not only smooth, but also a very high quality, durable coating, ready for any kind of floor covering.
