
2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54
- The composition of the screed depending on the types
- Required tool
- Material for work
- Backfill selection
- Expendable materials
- Choice of sheet material
Dry leveling floors are used when the entire amount of work needs to be done in the shortest possible time. Here we do not need to spend time preparing the mixture, and after completing the work - drying for a long time. As soon as it was possible to level the floor with a dry screed, you can start laying the flooring. But it is very important to know what it actually consists of and what you need to acquire. The composition of the floor screed will depend on the specific type and technology of work. A complete combination of components will allow you to get a really high-quality result.
The composition of the screed depending on the types
If we take into account such a brand of dry screed as Knauf, then their manufacturer identifies 4 main types of screeds:
- Alpha. They are used in the presence of an overlap with a flat base. This is practically the simplest option, which includes the use of an edge band, a layer for leveling the floor, plastic film and a screed made of gypsum fiber board.
- Beta. Consist of materials that can significantly increase the level of sound and thermal insulation qualities. Porous spongy materials can also be used. In any case, the base here also has a flat surface, which contributes to the speedy execution of work. The leveling layer is not used, but instead the dry mix, which is selected for this option, is filled.
- Vega. In addition to the leveling layer, the sound insulation layer is not passed through. For this, a dry mixture is used for the screed device, which will depend on the specific type of the future "final" floor. Mineral wool, which is a porous fiber material, can be used as a sound insulation layer.
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Gamma is the most difficult type of flooring with dry mixes. Here, there should always be layers from the options presented above: a layer of sound and heat insulation, an equalizing layer and a layer of porous-spongy materials. In addition to the main layer of sheet material, there must be a compensating layer located under the substrate. In this case, the slabs themselves for dry screed must correspond to the declared quality.
dry screed composition
As we can see, they are all divided into the indicated groups, depending on the purpose and the process of installation work itself. The specific dry screed method is chosen by the customer and must go through the sequential stages from the very beginning. Only in this case, in compliance with the technology, the "rough" version of the floor will be flat over the entire surface.
Required tool
To complete the whole range of work, you should prepare a tool for a dry screed with your own hands. The entire set may not always be useful, but it certainly won't be superfluous. The establishment of a specific list should be approached individually, depending on the current situation for the work. It will not be superfluous to attract an assistant, with whom even the slabs for dry floor screed can be moved much easier and without unnecessary effort. The tools include:
- A pencil combined with a tape measure. With their help, you can take measurements, make marks in the right places.
- Since the sheet material will have to be cut to the desired size in any case, a jigsaw or an ordinary knife, specially designed for cutting sheets of gypsum fiber board, will come in handy.
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Regarding sheet material, we will have to connect all the joints with self-tapping screws. In this case, a screwdriver or an ordinary screwdriver will suit us.
Floor screed composition Everything will depend on whether there is a rush and how effectively it is worth performing all types of work. In any case, the installation of floating floors must be done with good quality.
- A narrow spatula and a rule will be needed so that the dry screed solution is distributed evenly over the entire plane of the room.
- Metal profiles PN 27/28 are usually used as beacons. There are, of course, alternative options that will differ in their properties and qualities.
A paint brush can also act as a tool. But it can hardly be classified as a major one. It will come in handy when it is necessary to sweep the dry mixture from the joints of the sheet material before directly applying the glue.
You can, of course, list a large number of other related tools. But everything will depend on the specifics of the work performed at a particular stage, as well as on the preferences of the performer himself.
Material for work
In addition to the tools themselves, you should worry about the acquisition and material for performing all the work. You can make purchases in separate batches, or you can immediately buy a full range of all materials, which is the best option. Here you definitely do not have to worry that the quality of the products will be at the highest level. To install a floating floor, we need:
- GVL sheets, which are made of gypsum fiber. The most proven manufacturer is the German company Knauf. Their reduced size is 120 * 60 cm. This option is suitable for performing all types of work independently. They are presented in the form of two slabs connected to each other. In this case, the plates are displaced relative to each other to create a rebate. During the purchase, it will not be superfluous to buy 10 percent of the plates, which is necessary according to the calculations. This will allow you to easily trim them for a full docking.
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A dry screed with expanded clay sand can be performed,
dry screed composition or a completely different material can be selected, which is available in the range of construction products on the market. The most important thing is that there is an appropriate fraction not exceeding 5 mm.
- Consumables, which include plastic wrap, self-tapping screws, glue, damper tape, etc. The consumption of self-tapping screws is approximately 12 pieces per m2.
- Putty and primer. This is useful if the appropriate floor is made for a specific coating.
Backfill selection
A material such as a dry mix for sub-floor construction is of great importance. This is based on the fact that the particular room, as well as the floor covering, must be fully compatible with the backfill used. Most often, dry screed in bags is sold. Everything will depend on the required quantity.
The most popular backfill material is expanded clay. It is presented in the form of granules that have been fired in a special chamber. The porosity is very high, but the weight is insignificant. The fraction of expanded clay should be no more than 5 mm. If we take large dimensions, then the technology will not be followed, and, consequently, the strength of the dry screed will noticeably decrease. It is best if the granule size is exactly the same. Otherwise, over time, small granules can move among the large ones, and the floor will begin to "float".

There should not be any impurities in expanded clay. If it contains sand, then over time, when walking, the floors will begin to creak. Control is better with the purchase of loose pellets. When performing work, you should adhere to the minimum layer of expanded clay, which should be 30-40 mm.
Vermiculite has a layered structure. When making a direct dry mix for floor screeds, the material itself is heated to a certain temperature. As a result, such elements are obtained that resemble worms, in the form of sticks. Its main advantage is that it is very lightweight. Compared to the same expanded clay, the weight of the finished mixture is about 4 times less. The load on the existing floor is reduced to a minimum. If you choose vermiculite, then it should be expanded for a dry mix for a floor screed device.

The volcanic origin is perlite, which is also the material required to perform dry leveling of the floor. A firing process is also used here so that the granules can acquire all possible qualities and properties. The moisture is practically reduced to zero. In addition to perlite itself, sand based on it is also used.

Compavit is distinguished among the branded bases for filling dry floors. But it also has its own advantages, which include the low probability of marriage and falsification. This noticeably distinguishes it, for example, from expanded clay, where granules of various sizes, with various impurities, can be caught in one bag. Compavit is sold as a dry floor screed in bags. But it is worth noting that such material is based on expanded clay, with a size of up to 0.4 cm. Moreover, their density is noticeably higher. This allows you to obtain such qualities during operation as the absence of deformation and subsidence of the finished floor option.
If the surface under the floor is really flat and does not require any intervention, then you can refuse backfill. In this case, the mixtures for the device of floors go to the side, and instead of them it will be enough to put plates of expanded polystyrene. They fit closely to the surface, and on top of them the flooring is already being installed. The composition of the dry floor screed will differ in each specific situation.
Expendable materials
Among such materials should be attributed those components of the installation work that are necessary in any case and can be easily purchased at the nearest building products store. These are PVA glue or other possible glue, self-tapping screws, screws, polyethylene film used as a sound and heat insulating layer, edge tape.
In each case, you can calculate the consumption of materials. When connecting sheet material to each other, about 0.5 kg of PVA glue will have to be spent for each square meter. That is, 1 kg will be enough for the entire room. Special glue tubes may also be sold. It will be problematic to determine the number of packages, since they are all different, but about 800-900 grams of material will be spent on a standard room of 15-18 m2.
The edging tape extends from the perimeter of the entire room, while subtracting doorways.

But it is best to take it in stock, especially if the straight line is not observed along the entire perimeter. Its thickness in the standard is 8-10 mm.
All dry screed sheets require self-tapping screws. Approximately 6 pieces for each plate. In addition, you will have to spend at the docking points of adjacent rooms. Their length is 19 mm. These are the ones that are suitable for performing work on fixing sheets for dry floor screed. Longer options of 30 mm are necessary with a double layer of slabs, when there are no communications under the subfloor.
Choice of sheet material
When using a dry screed, an even floor is obtained subject to technology. As a floor element, you can use various sheet material, which can be:
- Drywall sheet.
- Plywood that resists moisture.
- OSB (oriented board) or chipboard.
- Gypsum fiber sheet (GVL). It may additionally have the property of moisture resistance (GVLV).
The choice of a particular option will depend on the humidity inside the room, temperature drops.

If we take into account the most effective complex of materials for making a dry floor OP 135 from the German manufacturer Knauf, then moisture-resistant gypsum plasterboard boards are laid in the basis. True, the weight of the product is more of a disadvantage. When performing work, a lot of dust from gypsum is generated during cutting. You can, of course, stock up on appropriate tools, like a jigsaw equipped with a dust catcher. But this will only require additional costs. Buying it for one room or work in an apartment is not worth it.
When the choice of mixtures and materials for dry screed is made, one should proceed from the recommendations of professionals, and it is also best to acquire it in a complex. This will avoid discrepancies in product quality as well as in batches. As a result, you get a very flat floor with high reliability and durability.

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