During the construction of the house, workers need to carry out a large amount of work and apply a variety of technologies. The erection of the walls is carried out from a variety of materials, and the interior decoration is made in the most unusual ways. A distinctive feature of floor leveling is that the owners not only see the result of this stage of construction every day, but also feel it under their feet. All this proves the importance of the correct implementation of the foundation.
Types of floor screed
- The classic method . Wet screed of cement-sand or concrete mortar. This method of leveling the base has been used in construction for a very long time. Carrying out work on a wet screed requires a lot of time, since the material must completely dry.
- Dry screed . It is carried out using plates from particleboard, OSB, fiberboard or plywood. The cost of such work depends on the initial quality of the foundation. The worse it is, the more material will be needed for leveling. The strength of some plates does not allow them to be laid in one layer, which also indicates the need for repeated leveling work.
- . This method is similar to the classical foundation, but fundamentally differs in the minimum amount of water in the sand-cement mixture. It does not flood, but falls asleep on the floor. To increase strength, polypropylene fibers can be added to the solution , playing the role of a reinforcing frame. Semi-dry floor screed, the technology of which will be discussed below, can be made in several ways, depending on the differences in the base plane.
The benefits of a semi-dry floor screed
- No need for additional waterproofing of the floor, since the solution does not flow.
- During the work it is not necessary to use protective gloves and shoes, since the sand-cement mixture contains only 25% water. This makes her unmarked.
- If the work is not carried out on the first floor, then there is no risk of leakage of the solution between the floors.
- The device of a semi-dry floor screed, the technology of which allows you to get a completely flat base, makes it possible also the complete absence of voids with air and cracks.
- The period of complete drying of the floor is only 4-5 days. After this time, you can lay the finish coating.
- The weight of a semi-dry base is much less than wet. This allows you to reduce the load on the floors of the building.
- Work with the solution can be carried out at temperatures up to -50 Β° C.
- The special structure of the material allows you to get a floor with excellent sound and heat insulation characteristics.
- Semi-dry screeds according to the European standard are made with special mixtures. A large saturation of the market with such types of materials and services leads to minimal margins on the work.
Disadvantages of a semi-dry floor screed
- Before commencing work on material compaction, the area of ββthe room is very dirty.
- When using special equipment, the cost of repair increases.
- The price for 1 m 2 of semi-dry screed depends on the height where the work is carried out. For example, the cost of flooring on the 1st and 20th floors differs by 30%. This is due to the need to lift all materials and equipment.
- Semi-dry solution is very difficult to mix manually.
- Often, builders do not know the exact amount of water in the mixture, so they pour it insufficiently or too much. This leads to a violation of technology and an unexpected result.
- A semi-dry screed must be carefully tamped, otherwise it will constantly crumble and even creak under your feet.
Types of semi-dry screeds
- Screed without backing. The material is laid on a bare concrete base.
- With polyethylene backing. The solution in this case does not apply to the rough base and walls. This type of screed is also called "floating".
- With heat-insulating backing. Mineral wool slabs most often act as an additional layer. This is especially true on the ground floors of houses and in private buildings.
- With soundproofing underlay. The sand-cement mixture itself does not transmit sound well. In addition to it, foamed polyethylene or noise suppressing membranes can be used.
- With reinforced mesh. They give the floor more strength.
- With fiber. Such a floor is able to withstand very large loads.
Some of these types can be combined with each other, so the floor screed is optimal for a given room. The technology of the semi-dry screed device is divided into several stages.
Preparing the base for a semi-dry floor screed
- Before starting work, the base is completely cleaned. Garbage is cleaned with a broom, and small particles - with a vacuum cleaner.
- Set to zero. It helps to accurately measure the height of the base.
- If necessary, large floor defects are putty. Semi-dry screed, laying technology which allows you to create a flat surface, still does not guarantee penetration into all the flaws of the base. The remaining voids may subsequently cause cracking.
- The entire surface of the floor must be primed. This helps bond the new layer to the old one. The primer dries for several hours.
Installation of beacons and waterproofing
Lighthouses are called guiding elements that serve as landmarks for the horizontal level of the future floor. They help the builder to lay out the solution of the desired thickness.
Waterproofing for a semi-dry screed is not required, but walls and columns must be protected from mortar. This is done so that the compression and subsequent expansion of the vertical structures does not affect the condition of the floor. Above the level of the future screed, a damper tape is glued to all surfaces, it will prevent cracking of the material. After the floor has dried, it must be removed with a sharp knife.
Semi-dry floor screed, the device technology of which implies the mandatory presence of beacons, allows their implementation in several ways. One of them involves the installation of landmarks on two opposite walls. Lighthouses consist of a tamped mixture. Their height is accurately measured from the zero level.
Lighthouses can also be planks fixed on self-tapping screws or concrete. Their level, as a rule, is 8-10 cm higher than the base.
Similar beacons are installed in strips every 180-190 cm, if a two-meter rule is used. As its length decreases, the distance between landmarks becomes shorter. Their height is measured by a thread stretched between the walls from the first lighthouses.
During floor leveling, beacons should not be displaced. To do this, they need to be securely fixed. As necessary, the future floor is reinforced.
Preparation of a solution for semi-dry floor screed
This process can be carried out in several ways. The simplest of them is to dilute the finished dry mixture with water. In this case, you only need to follow the instructions.
If there is no ready-made mixture, then you can do it yourself. To do this, mix one part of the cement and three - peeled coarse-grained sand. If necessary, plasticizer and fiber are added. Everything is placed in a concrete mixer, and gradually water flows into it. Semi-dry floor screed, the laying technology of which will be discussed below, involves obtaining a solution of a certain consistency. Such that when compressed in a fist, it forms a lump, but does not emit water.
Semi-dry fiber-reinforced screed withstands very high loads. The right amount of solution is obtained by constantly adding dry components and water.
The device is a semi-dry floor screed. Concreting technology
After completion of the preparatory work, you can proceed to direct concreting of the surface. Semi-dry floor screed, the technology of which provides for the performance of work by several builders at the same time, begins with falling asleep mixture between the rails. After that, the material is aligned with the rule just above the beacons. The mixture is pulled onto itself. If necessary, you can perform wave-like movements as a rule, this will help remove excess material in neighboring areas.
Until the concrete mix begins to dry, it must be tamped and rubbed. All this must be done within 6 hours after alignment. A special machine is used, which allows you to make the floor surface even and smooth. During the operation of the equipment, the material settles a little.
Material processing ends with a check of the horizontal and evenness of the resulting floor. The level must be clean.
In order to gradually dry, the floor surface is covered with polyethylene for 12 hours, this will help prevent moisture from evaporating too quickly. After which the floor dries for at least four days.
Semi-dry floor screed with your own hands: device and technology of work
It is possible to carry out independent concreting of the floor. The only difference is the use of a large area instead of an ordinary grout to smooth out the usual grout. For the convenience of working with it, the floor can be covered in small segments. Do-it-yourself semi-dry screed device technology provides for quick and consistent execution of all stages of the process. Therefore, one person can knead the solution, the second - stack it and level it, and the third - overwrite.
Components of the cost of screed
When ordering a screed in a construction company, its final cost will consist of the costs of:
- concrete and dry mix;
- transportation and lifting of all materials and equipment;
- Additional materials;
- performance of work.
Reviews on the semi-dry screed method
Many of those who performed the floor leveling work on their own note that the main thing is to choose the right amount of water. The passage of the process of hydration of cement depends on this. If there was not enough water in the solution, then when the moisture gets onto the finished surface, the crystals of the material can begin to grow again, and the floor will creak.
Most experts respond positively to the semi-dry screed method. However, its maximum service life is still unknown.
Thus, a semi-dry floor screed, the implementation technology of which was considered in the article, can be produced by both professional workers and apartment owners themselves.