Wet floor screed: device technology, pros and cons, opinions of experts. Caring for a floor screed after pouring Do-it-yourself wet floor screed

Wet screed can be made of 4 types:

Knitted. The simplest option. The screed is laid directly on the base (slab). Waterproofing and finishing flooring can be laid on the screed.
On waterproofing. A waterproofing layer is laid on the slab, and a screed is placed on it.
On thermal insulation. As a rule, such screeds are used on soil foundations. First, sand is laid on the ground and compacted, then comes insulation, waterproofing and screed (necessarily reinforced, since it lies on the insulation). If thermal insulation is laid on a slab, then sand bedding is not needed.
With self-leveling coating. Self-leveling coating The subfloor is poured onto a hardened screed to create a perfectly flat and smooth base for laying sensitive coatings (for example, linoleum).

Installation of wet screed subfloor

The process of preparing and pouring a wet subfloor screed with your own hands:

Preparing the base. If it is a stove, it is cleaned of dust and debris. If it is soil, remove all vegetation, compact the underlying base (expanded clay, crushed stone, gravel) to the required height, then compact a sand cushion 10 cm high. If you are going to make a knitted screed, then the slab needs to be primed (pour a thin layer of primer and level it over the entire surfaces with a roller or brush; the primer dries for 3-5 hours).
Thermal insulation. Insulation can be laid on the slab if desired, but on sand preparation on the ground – it is obligatory. In any case, the insulation must be rigid.
Waterproofing. A waterproofing layer is not needed only for a knitted screed (instead, a damper screed is laid along the perimeter of the walls edge tape). In all other cases, waterproofing is laid (with a 10-15 cm overlap on the walls). If the waterproofing is rolled, then it is laid overlapping with an overlap of 10-15 cm.
Reinforcement. Mandatory screed reinforcement is required when creating a subfloor on the ground. In other cases - optional. Reinforced mesh need to be installed at a distance of 1-2 cm from the base.
Installation of "beacons". Lighthouses are metal profiles(for example, T-shaped), along which the screed is aligned. Therefore, they need to be aligned horizontally. The easiest way is to install beacons on a solution (the solution should be the same as that which will be used for the screed). Mix the solution and place it in piles along the future profile line. Place the profile on the solution and level it with water or laser level. The height of the level of the beacons should be 3-5 cm. The beacons must first be placed along the walls with a distance of 20 cm from the walls. The step (distance) between the beacons should be 1-1.5 m (the main thing is that the step should be less than the length of the rule that you will use align the screed). Align the beacons both along and across between adjacent profiles. The solution under the beacons must harden so that the subfloor screed can be leveled using them.
Preparing the screed. The screed can be made from ordinary cement-sand mortar(1 bucket of cement for 3 buckets of sand; as a result, the solution should not be liquid or thick), but it is better to include tile adhesive in a portion of cement (if you have extra packaging). The glue increases the grip (adhesion) and strength of the screed. Also, the market is already filled with special solutions for wet screed subfloors. If you bought a special solution for screed, strictly follow the proportions indicated by the manufacturer on the packaging. In any case, preparing the solution begins by pouring water into the vessel, and then only everything else. Also, the prepared solution should be used as quickly as possible.
Filling and leveling the screed. This stage of work is best done by two people: one fills and levels the screed, while the second prepares the next portion of the solution. You need to align the screed with the beacons towards you, moving the rule (or rod) left and right. Filling the screed begins with far corner premises, moving towards the exit. After each leveling of a new portion of the screed, the solution must be pierced with wire in several places (during mixing, it may form air gaps, which will come out when punctured). After completing the work, a day later you can stick out the beacons, treat the cracks with a primer and seal them with the same solution composition.
Finish self-leveling self-leveling layer. The self-leveling layer is applied under sensitive coatings (for example, linoleum). But before pouring it, the screed must completely harden (this takes 1 month).

Do not ventilate or create drafts in the room under any circumstances during the entire curing period of the screed. In short, do nothing for a whole month. Many people make a huge mistake by trying to reduce the drying time of the screed. The point is just that The screed should not dry out, but harden. And this is a smooth process. If it is accelerated, microcracks may appear on the surface of the screed.

Some will say that microcracks are not scary at all. Just the opposite. The screed dries from below, not from above. Therefore, if microcracks appear, they come from the very bottom. To prevent cracks from appearing, you need to literally check the surface of the screed every day for dryness. If it is very dry, moisten the surface with a wet roller.

If microcracks do appear, immediately cover them with solution and moisten the entire surface with a damp roller.

It is advisable to screed the floor in one room in 1 day. If you have unused solution left, it will not work next time, because it will set quite strongly, and it cannot be diluted with water.

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Every adult, even without special construction education, understands that in order to lay any covering on the floor in a room, you must first level its base, which is why you need a floor screed. What is a floor screed? This is a construction procedure for forming a flat surface on the floor.. Today there is great amount types of screeds. When performing renovations of apartments, offices and industrial premises Both wet and dry floor screed are often used. The screed solution, called wet, is used quite often and is prepared from sand, cement and water. Additional fillers can also be used. This is the simplest and inexpensive way leveling the floors.

The main tasks of a wet screed:

Smooth surface;
strengthening the sexual foundation;
additional sound insulation, thermal insulation of the room;
hiding the structural elements of a heated floor.

Types of wet screed

According to the specifics of preparing the type of floor surface and making the final layer, wet screeds are divided into four types, which are presented below.

You can also make self-leveling floors by using a thinner mixture that can spread onto the floor without physical intervention. But it’s not worth using only self-leveling floors without creating a key screed.

Preparing the subfloor

Preparing the floor for a wet screed involves rough renovation work, which include:

dismantling the old screed;
clearing debris from slabs;
base primer.

Note: The primer must be allowed to dry for five hours!

If the base is soil, then it is first cleared of vegetation, then a layer of sand (at least 10 cm) is poured. When using expanded clay for this purpose, sand is also poured on top of it. The formed layer is carefully compacted. For better shrinkage, the embankment can be slightly moistened with water. With the use of expanded clay, a wet floor screed is much simpler and cheaper, since it will be used minimal amount solution. If repair work is carried out in the bathroom or toilet, then the water pipes are laid at the same time.

Thermal insulation

As thermal insulation material expanded clay is used, polystyrene foam boards. But the insulation must be sufficiently rigid. Expanded clay has worse thermal insulation and sound insulation characteristics, but is more reliable and has a longer service life. When performing a wet screed on the ground, insulation must be carried out, and on slabs in some cases (for example, if there is a basement below).

Waterproofing

Roofing material, a thick film, can be used as a material for waterproofing. Strips of material should overlap by up to 15 cm and overlap by 10 cm on the walls facing water pipes, which must be coated with sealant above the planned level of filling the solution. Waterproofing must be carried out in bathrooms, as well as in other rooms that are connected, for example, to the basement.

Reinforcement

When screeding on the ground, it is recommended to reinforce it with reinforcement. For this, a steel mesh welded from reinforcement can be used. You can also simply add a special fibrous metal (plastic) material - fibrin - to the cement mortar.

Installation of additional equipment

If it is planned to lay wiring, install a heated floor system, repair and construction work is also carried out at this stage, with mandatory consideration of all technological specifics.

Stages of performing a wet screed

Wet screed is carried out in several stages, which are given below.

Placement of beacons

To ensure that the wet floor screed is completely level, during its implementation a beacon system is used, which is formed on the floor from profile slats. To install the beacon strip, it is recommended to use a solution designed for screeding.

First, screws are screwed into the base of the floor parallel to the wall at a distance of 20 cm, their heads must be at the same level (you can check using a special building level), but below 10 mm of the planned screed level (depending on the height of the slats used).
It is worth maintaining a distance of up to 80 cm between the screws; this is no longer recommended, as the slats installed on them may bend.
The next line with screws is placed every 1.5 meters from the previous line. Here you need to take into account the length of the rule planned to be used for alignment cement mortar. The rule should lie on two parallel slats.
Next, the mortar is applied to the screws and the slats are mounted. During the installation process, it is necessary to check the evenness of the resulting plane using a level. After installing all the slats, you need to let the solution dry.

The use of beacons is used even in small areas. There should be at least two of them so that the solution can be leveled.

Solution used

After full preparation To perform a wet floor screed, you need to prepare a mixture. As a mortar for floor screed, you can already use ready-made mixtures, specially designed for leveling floor surfaces. Currently on the market building materials They are available in a fairly wide range and may differ from each other in some characteristics. To prepare them for use, you must strictly follow the manufacturer's instructions.

Proportion of standard solution: 1 part - cement, 3 parts - sand. To improve the strength characteristics, you can additionally add adhesive mass, which is used for tiling work, into the solution.

The finished mixture should not:

spread too much;
be dry.

It is recommended to order concrete in a ready-made state. It is made of much better quality. Besides, it’s much more profitable. Concrete is commonly used to make similar works in private country cottages, as well as on the first floors of buildings. Thick layer wet screed made of concrete mixture on the upper floors it is used only in certain cases.

Pouring the floor

Important! To obtain a high-quality screed, the area of the room must be filled at once, since the cement solution tends to harden within an hour, after which it will be impossible to adjust it.

Grinding

If as liquid screed concrete was used, then after it hardens, the surface is polished with special grinding equipment (a grinder with a special attachment can be used). This event will help remove noticeable irregularities and prepare the floor surface for laying any type of flooring.

In this article we will tell you how to properly make a wet (concrete, cement) screed for a subfloor with your own hands. Subfloors with wet screed can be laid on floor slabs or on the ground.
Wet screed can be made of 4 types:
o Knitted. The simplest option. The screed is laid directly on the base (slab). Waterproofing and finishing flooring can be laid on the screed.
o On waterproofing. A waterproofing layer is laid on the slab, and a screed is placed on it.
o On thermal insulation. As a rule, such screeds are used on soil foundations. First, sand is laid on the ground and compacted, then comes insulation, waterproofing and screed (necessarily reinforced, since it lies on the insulation). If thermal insulation is laid on a slab, then sand bedding is not needed.
o With self-leveling coating. The self-leveling subfloor coating is poured onto a hardened screed to create a perfectly flat and smooth base for laying sensitive coatings (for example, linoleum).
The process of preparing and pouring a wet subfloor screed with your own hands:
1. Preparing the base. If it is a stove, it is cleaned of dust and debris. If it is soil, remove all vegetation, compact the underlying base (expanded clay, crushed stone, gravel) to the required height, then compact a sand cushion 10 cm high. If you are going to make a knitted screed, then the slab needs to be primed (pour a thin layer of primer and level it over the entire surfaces with a roller or brush; the primer dries for 3-5 hours).
2. Thermal insulation. Insulation can be laid on the slab if desired, but on sand preparation on the ground – it is obligatory. In any case, the insulation must be rigid.
3. Waterproofing. A waterproofing layer is not needed only for a knitted screed (instead, a damper edge tape is laid along the perimeter of the walls). In all other cases, waterproofing is laid (with a 10-15 cm overlap on the walls). If the waterproofing is rolled, then it is laid overlapping with an overlap of 10-15 cm.
4. Reinforcement. Mandatory screed reinforcement is required when creating a subfloor on the ground. In other cases - optional. The reinforced mesh should be installed at a distance of 1-2 cm from the base.
5. Installation of “beacons”. Beacons are metal profiles (for example, T-shaped) along which the screed is aligned. Therefore, they need to be aligned horizontally. The easiest way is to install beacons on a solution (the solution should be the same as that which will be used for the screed). Mix the solution and place it in piles along the future profile line. Place the profile on the solution and level it using a water or laser level. The height of the level of the beacons should be 3-5 cm. The beacons must first be placed along the walls with a distance of 20 cm from the walls. The step (distance) between the beacons should be 1-1.5 m (the main thing is that the step should be less than the length of the rule that you will use align the screed). Align the beacons both along and across between adjacent profiles. The solution under the beacons must harden so that the subfloor screed can be leveled using them.
6. Preparing the screed. The screed can be made from ordinary cement-sand mortar (1 bucket of cement for 3 buckets of sand; as a result, the solution should not be liquid or thick), but it is better to include tile adhesive in a portion of cement (if you have extra packaging). The glue increases the grip (adhesion) and strength of the screed. Also, the market is already filled with special solutions for wet screed subfloors. If you bought a special solution for screed, strictly follow the proportions indicated by the manufacturer on the packaging. In any case, preparing the solution begins by pouring water into the vessel, and then only everything else. Also, the prepared solution should be used as quickly as possible.
7. Filling and leveling the screed. This stage of work is best done by two people: one fills and levels the screed, while the second prepares the next portion of the solution. You need to align the screed with the beacons towards you, moving the rule (or rod) left and right. Filling the screed begins from the far corner of the room, moving towards the exit. After each leveling of a new portion of the screed, the solution must be pierced with wire in several places (when stirring, air layers may form in it, which will come out when pierced). After completing the work, a day later you can stick out the beacons, treat the cracks with a primer and seal them with the same solution composition.
8. Finish self-leveling self-leveling layer. The self-leveling layer is applied under sensitive coatings (for example, linoleum). But before pouring it, the screed must completely harden (this takes 1 month).

Do not ventilate or create drafts in the room under any circumstances during the entire curing period of the screed. In short, do nothing for a whole month. Many people make a huge mistake by trying to reduce the drying time of the screed. The point is that the screed should not dry out, but harden. And this is a smooth process. If it is accelerated, microcracks may appear on the surface of the screed.
Some will say that microcracks are not scary at all. Just the opposite. The screed dries from below, not from above. Therefore, if microcracks appear, they come from the very bottom. To prevent cracks from appearing, you need to literally check the surface of the screed every day for dryness. If it is very dry, moisten the surface with a wet roller.
If microcracks do appear, immediately cover them with solution and moisten the entire surface with a damp roller.
It is advisable to screed the floor in one room in 1 day. If you have unused solution left, it will not work next time, because it will set quite strongly, and it cannot be diluted with water.

It is difficult to independently determine which floor screed is best. If 10 - 20 years ago only cement-sand was used, now much is known various types materials and manufacturing methods.

Despite this, the most popular options are “wet”, “dry” and “semi-dry” methods.

Each of them has significant differences in installation and has its own specific advantages and disadvantages.

What should it be like?

The flooring material, or rather the method of its installation, implies compliance with certain requirements for the base during implementation.

This applies directly to the surface on which the finishing coating will be installed. In general, when performing a screed, it is important to consider the following points:

The area must be flat and leveled horizontally. Deviations are no more than 0.3 mm per 1 p/m;
any surface (dry, semi-dry or wet) must be protected with thermal insulation;
The bottom of the base is protected from moisture by a layer of waterproofing.

Positive characteristics inherent in each of the known filling methods:

High strength.
Resistance to atmospheric and climatic influences.
Improves surface quality.
Create good warmth, -hydro and -sound insulation.

Any of the types are good, but you can get the optimal result by completing the necessary list of works using different technologies and materials.

Wet screed

For wet screed, crushed stone or gravel filler is used.

When fully analyzing the question of which floor screed is best, you can start with wet method fills. It is made using cement, so there are only 2 options: concrete and cement-sand screed.

The difference between them is that the first method requires a filler with a coarse structure: crushed stone or gravel. The remaining parts are absolutely identical, but depending on the purpose of the pillow, the proportions of the binder composition may differ.

If we compare the pros and cons of concrete and cement-sand foundations, we can highlight the strength of the first method. Due to this, it is widely used both inside and outside the house for rough and finishing screed. In addition, large-scale capital construction is carried out with its help.

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Its wide popularity is explained by additional features of the composition:

The wet screed of their concrete is poured and hardens much faster than the cement-sand screed.
During processing large areas the total cost is much less than dry or semi-dry.
It is possible to make a layer of any thickness, which involves the use of concrete to level almost any surface with curvature.

The hardening time of the mixture also depends on the thickness of the layer.

Analysis of the mortar mixture can reveal several disadvantages inherent in this method. First of all, this is mandatory reinforcement of the structure. In addition, there are a number of other reasons why many people prefer other methods:

long hardening time of the mixture, depending on the thickness of the layer;
significant shrinkage and possible cracking;
the poured base must be constantly monitored and periodically moistened;
labor-intensive process self-production mixtures;
sufficiently complex alignment of the horizontal direction of the surface.

The finished base is quite heavy, which contradicts the requirements for pouring the screed into apartment buildings, and in private cases it will lead to additional load on the foundation.

Semi-dry

The mixture of semi-dry screed is evenly distributed throughout the room

The percentage composition of the components of a semi-dry screed is similar to those from which a wet screed is made.

However, the mixture differs in its moisture content. Based on the name, the amount of water in this case needs to be added by half.

As an example, we can give a composition for making a mixture in proportions of 1 to 3, respectively, cement and sand. For this you will need only 24 - 26 liters.

After the material is distributed, it is compacted

Semi-dry screed is performed as follows. The composition is evenly distributed over the previously designated area. Laying occurs in several layers, where each is compacted.

Having reached the desired level, indicated by the beacons, the excess is removed by the rule. Walking on the surface is allowed after 2-3 hours. At this time you need to do final leveling and smoothing the base with a metallic brush.

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To draw a conclusion which floor screed is best suited in your situation, you need to take into account some features of the semi-dry mixture before the wet manufacturing method. First of all, we can highlight the period during which the compositions mentioned above harden. In addition, there are several other distinctive features:

High density semi-dry method.
No reinforcement required.
Shrinkage occurs during the drying process.
This type of screed is much easier to install; installation of a finishing layer is allowed, on which it is laid immediately after complete drying and hardening. decorative coating. For instructions on installing semi-dry screeds, watch this video:

The disadvantages of the semi-dry method of pouring screed relate only to the large weight of the structure and the impossibility of installation thin layer. Others on this moment not found.

Dry

The technology used to install dry screed differs significantly from the work required for installation of wet and semi-dry screed.

For this case use sheet materials and bulk heat insulator. The order of work is as follows:

On a rough screed or concrete base wooden logs or slats are laid out.
After they are aligned horizontally, the elements are fixed to each other. Easiest to use for this metal corners, intended for roof assembly.
Between wooden joists Expanded clay is poured.
Sheets of chipboard, OSB or plywood are laid on the bedding, which are attached to the slats with self-tapping screws and glued together with glue.

Dry screed is quickly and easily installed

Compared to the dry method, wet and semi-dry floor screeds will cost much less, but this technology has its own advantages that are not typical for options that use cement or concrete.

ease and speed of installation, which will allow you to do everything yourself and in 1 day;
good soundproofing properties materials;
when planning the installation of a heated floor system, it is considered the most acceptable option. The design can be easily disassembled if a malfunction occurs in the system.