Floor Screed (140 Photos): What Is It - A Concrete Screed Device Under A Wooden Floor Surface In An Apartment, Materials For A Floating Structure

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Floor Screed (140 Photos): What Is It - A Concrete Screed Device Under A Wooden Floor Surface In An Apartment, Materials For A Floating Structure
Floor Screed (140 Photos): What Is It - A Concrete Screed Device Under A Wooden Floor Surface In An Apartment, Materials For A Floating Structure

Video: Floor Screed (140 Photos): What Is It - A Concrete Screed Device Under A Wooden Floor Surface In An Apartment, Materials For A Floating Structure

Video: Floor Screed (140 Photos): What Is It - A Concrete Screed Device Under A Wooden Floor Surface In An Apartment, Materials For A Floating Structure
Video: floating floor on concrete 2024, March
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Not everyone knows what a floor screed is. It is a necessary element of construction or major repairs and performs a number of important functions. The main purpose of the screed is to level the floor, give it rigidity and hide engineering communications. For systems such as underfloor heating, the screed also performs a protective function. In addition to the main purpose, the screed is necessary to increase the insulation of the room. It prevents heat loss through the lower floors and increases the level of living comfort due to sound insulation properties.

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Equipping a floor screed is important and necessary, but its installation is difficult and requires some skills. It is important to know the intricacies of the process and the peculiarities of the technology of wet, semi-dry or dry screed, depending on which type of screed was chosen.

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The construction market today offers several types of screeds, which are conventionally divided into several categories: by component composition, by the method of adhesion, by the method of laying, by purpose.

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By material composition

The composition of the material is directly influenced by the type of screed: wet, semi-dry or dry. At the same time, leveling mixtures with self-leveling technology should be considered along with wet (liquid) ones.

The wet screed is considered an “ageless classic” in construction. It turns out to be solid, solid and durable due to the components in the composition that reliably adhere with water and harden in air.

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There are a lot of options for a wet screed:

  • Cement. A simple and reliable mixture of cement and alluvial river sand, when water is added, forms a mass of consistency that is convenient for pouring, quickly hardens and serves for many years. For the price, such a screed belongs to the cheapest, and in terms of performance, it is one of the most reliable;
  • Concrete. In its composition, it is similar to cement, since it is based on a synthetic binder and alluvial river sand that has undergone various treatments. Crushed stone may also be present. Claydite concrete screeds are popular;
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  • Mosaic. In essence, it is a concrete screed without crushed stone, but with the addition of polymers and polymer cement. As a decorative component, marble and granite chips, colored expanded clay concrete and other substances are introduced into the composition;
  • Anhydrite. It has a fundamental difference from the texture of a concrete or cement screed. Anhydride is a "dehydrated" gypsum, and upon subsequent addition of liquid, it turns into a homogeneous pliable mass that resembles a self-leveling floor rather than a rough concrete screed. It does not require additional efforts to reinforce and level the floor surface, but it does not allow making the thickness large enough. The best option is 25-35 millimeters;
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  • Asphalt. It is made from a binder and a dry mixture of fine fractions. The performance characteristics of the asphalt screed are at a height, since it is very wear-resistant (unlike the same gypsum one), it copes well with sound insulation and thermal insulation and does not contain substances harmful to health;
  • Synthetic. Such a mixture implies the presence of synthetic fibers of plastic or metal, which strengthen the screed. Additional components make it as strong as reinforced concrete, but less heavy;
  • Mortar or leveling. These are ready-made mixtures based on gypsum with the addition of various fibers, metals and binders.
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The self-leveling floor will stand out in a separate category. It is used in cases where the surface of the subfloor is not in a deplorable state or as a topcoat on a concrete screed. A self-leveling screed is more suitable for independent use without the help of a professional, it gives a good result, however, the cost is several times higher than a cement or concrete screed. Its maximum height is 30 mm.

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A semi-dry screed suitable for quick work on a relatively flat floor surface, for the most part has the same composition. Different manufacturers only differ in the type of plasticizers and the proportions of the components. There are 4 of them in total: coarse sand, cement powder, polypropylene fibers, plasticizers. When preparing the mixture, water is added, but in a smaller amount than for a liquid screed.

A semi-dry screed does not require reinforcement and additional protection, since the fibers in the composition are designed to increase ductility and strength.

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Dry screed is a more modern method.

It is a layer-by-layer alternation of materials:

  • Polymer film required to protect against moisture and condensation.
  • Damper tape. Also called edging tape.
  • Beacons and guides that regulate the uniform distribution of the substance over the floor area.
  • Leveling layer. Substance for dry filling, of which the main part and thickness of the screed is composed.
  • Sheet or board material, leveling the surface of the free-flowing layer.
  • PVC protective film that covers the hydrophobic leveling sheets;
  • Mastic, glue and self-tapping screws for joining sheets.
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In the composition of the dry screed, the substance for dry backfill is different. Most of its types do not require professional intervention.

Varieties of dry screed by component:

  • Sand based mixtures. Most often they consist of alluvial river or quarry sand and cement. Sometimes other components are present in the composition to improve the absorption properties and increase the wear resistance of the abrasive substance. Sand that has undergone several processing procedures and is purified from living organisms and impurities has a number of advantages: it does not "sag" over time, it allows you to do the job quickly and cleanly. It is an ecological product of organic origin.
  • Concrete mixes. With the addition of gypsum, sand and expanded clay.
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  • Slag backfill. Despite the existing prejudices about the use of slag in a residential area, this material consists exclusively of natural components. It perfectly copes with its task as a dry screed and is distinguished by its low cost, since slag is a production waste. There are also several types of it:
  • Domain. Very similar in properties to cement mixtures, but less hydrophobic and more frost-resistant;
  • Mineral wool. This is not pure slag. Mineral wool is obtained by thermal treatment of slag from metallurgical production.
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  • Coal. Suitable for use in all types of screeds. Differs in cheapness and optimal composition;
  • Fuel. It is kept for 3 months in grooves, and then used to install a screed with high insulating performance.
  • Expanded clay. It is used in its pure form, since this low-melting clay after heat treatment already has all the necessary properties: low weight, low cost, organic composition, ease of installation work.
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  • Perlite. Grains of volcanic origin, "blown up" by calcining in a furnace to a light porous state, are used as expanded clay.
  • Vermiculite. It combines the qualities of the two previous porous materials, but costs a little more.
  • Boards based on cement and wood fibers. They are durable, smooth, even, do not require additional efforts during installation, are not afraid of moisture, bio-resistant, do not freeze, weigh a little, easily mounted, are cheap.
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By the way of adhesion

It is customary to distinguish 4 types of adhesion of the screed to the base:

Bound

This type of screed got its name due to the fact that the liquid mixture directly binds or adheres to the surface of the subfloor without using any cushioning building material. The pouring turns out to be solid, strong, wear-resistant, but it is fraught with a number of difficulties.

First, a lot of water must be added for a good bond. This creates a risk that the mixture will leak to neighbors. Secondly, the screed shrinks strongly after evaporation of moisture. This can significantly reduce its width. In addition, water "stretches" the substance, and when it hardens, cracks appear on the surface. Drying is uneven and one part of the screed may sink deeper than the other. Such a screed is especially dangerous when it is poured over a heated water floor.

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It is required under the following conditions:

  • Large differences in floor height;
  • Low ceilings, for example, in "Khrushchev", which do not allow to raise the floor line high;
  • The need to install a wear-resistant and durable coating.
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On a release layer or underlay

From the name it is clear that this screed is devoid of adhesion (adhesion) to the surface of the subfloor in the room. A thin polymer film is located between a layer of a liquid mixture or dry backfill. It is necessary in damp rooms and when there is a risk of condensation. Also, the underlayment helps to protect the wood floor from "sucking" moisture from the liquid screed. If the liquid evaporates from it at an accelerated rate, the screed will crack and the wood flooring may begin to rot.

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Floating

Such a screed is inherently close to a multi-layer dry screed and is a modified version of pouring or backfilling on a substrate. The fundamental difference is that in addition to the moisture-proof film, a layer of insulating material is also laid to prevent heat loss and increase the noise protection in the room. Such a screed, due to the number of layers, increases in thickness from 30 to 40-50 mm.

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Reasons for use:

  1. Poor floor performance;
  2. The presence of a warm floor system;
  3. Ground floor of an apartment building with or without a basement downstairs;
  4. For further finishing, the most even floor is required;
  5. The budget is limited;
  6. The finish will be soft: linoleum, carpet, laminate.
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Precast or leveling

In a design of this type, there are no bulk and liquid elements at all. It consists of layers or roll materials that provide protection against moisture, noise, cold and are mounted with adhesives in solid plates.

A prefabricated screed is necessary in cases where the subfloor is sufficiently dry and level, and installation work must be carried out quickly.

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By styling method

Here again the familiar division of varieties into solid (wet), semi-dry and leveling screeds is used.

Solid is leveled by hand, for semi-dry a special machine is required for kneading and tamping the material, and leveling mixtures are leveled under their own weight without additional manipulations.

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By appointment

The screed is a multifunctional coating.

It is necessary in such situations:

  • Leveling the floor surface. In the construction of any building, wooden or reinforced concrete floors are used. Despite the massive nature of their production, they are not absolutely identical. One plate from another may differ in varying degrees in thickness, width and length. Moreover, these indicators sometimes differ when measuring the same slab at different points. As a result, the overlap has noticeable joints, depressions and irregularities that will not fall on any type of finish. Any technology is suitable for leveling the subfloor, whether it is pouring, based on concrete, or dry backfill from expanded clay. The nuances of the choice depend on the location of the room and its microclimate.
  • Creation of a sloped surface. This option is less common. As a rule, a sloped floor is required in large showers and rooms where there is a drain. Due to the high humidity and the characteristics of the inclined screed, only liquid mixtures can be used for such work.
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  • Preparation of the surface for the installation of the floor covering. Here we are also talking about leveling, but for different purposes: so that the laminate lies perfectly, so that there are no creases on the linoleum, in order to reduce the consumption of glue when tiling.
  • The need to block utilities and heating systems. All types of screeds are relevant here, except for the national team. A liquid floor is more suitable for a water floor, a leveling mixture for a film floor. In this case, the screed simultaneously levels the surface above the heating system and protects the system itself from moisture and damage.
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  • Increase of thermal insulation in the room. This use of the screed is relevant for country houses, summer cottages, apartments on the ground floor, which are colder than others due to their proximity to the ground.
  • Improving indoor sound insulation. The screed does not save from the neighbors above and from the side, but the sounds from below are not audible at all. And neighbors have no complaints about prancing children, pets running around the apartment and untimely rearrangement of furniture.
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Advantages and disadvantages

Each type of screed has its own characteristics, advantages and disadvantages.

Pros of a wet screed:

  • Able to level any floor, even if its surface is in a very poor condition;
  • Suitable for creating sloping surfaces in sinks, showers and garages. Needed in the premises for the organization of the drain;
  • Solid, reliable, wear-resistant screed, which is widely used even in industrial premises;
  • Materials are not very expensive;
  • Can be used to level the floor along the laid contour of the warm floor;
  • Creates an excellent soundproofing layer;
  • Some varieties can serve as both a rough finish and a top coat at the same time.
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Cons of a wet screed:

  • Its installation is time consuming and complicated, it cannot be done without the help of professionals;
  • A special technique is required for mixing the mixture and leveling the surface;
  • The work is dirty, there is a risk that the mixture will leak to the neighbors;
  • The concrete or cement screed is very heavy, giving a large load on the floor;
  • Cold in itself;
  • Time for complete drying of the screed - 28 days;
  • It can shrink after moisture evaporation, which will lead to cracks on the surface and the risk of damage to the underfloor heating under the screed.
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A separate type of liquid screed is leveling mixtures or self-leveling floor.

Its advantages:

  • Weighs less than a concrete screed;
  • Easy to operate, does not require specialist intervention. To level the floor surface, it is enough to follow the manufacturer's instructions;
  • Leaves no dirt and dust, not thick enough to leak to neighbors;
  • No special kneading technique required;
  • The mixture is self-leveling, that is, it takes the desired shape under the weight of its own weight;
  • Serves at the same time as a decorative coating, can be patterned;
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  • Dries several times faster;
  • The ideal base for any type of floor finish;
  • Protects electric and infrared underfloor heating;
  • Promotes an increase in thermal insulation and sound insulation in the house;
  • Not afraid of moisture.
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Its disadvantages:

  • The floor surface must be relatively flat and clean. The mixture does not cope with difficult cases;
  • The maximum layer height is 30 millimeters. This is not always enough for a screed;
  • High material consumption at a very high price.
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Semi-dry screed deserves attention due to its advantages:

  • A small amount of water solves the problem of mixture leaks to neighbors. They just don't happen;
  • Reducing the liquid in the composition by 3-4 times also reduces the drying time of the screed;
  • Practically does not shrink;
  • Does not crack after drying;
  • It is cheaper than liquid analogs;
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  • Strong and reliable;
  • Combines with the underfloor heating contour;
  • Increases the level of indoor comfort;
  • Consists of environmentally friendly components.
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But it also has a number of disadvantages:

  • The coating is hydrophobic. Forbidden for use in wet areas;
  • It is better to cope with leveling a relatively smooth floor in a new building than when re-installing a screed on a very uneven floor surface in an old house;
  • Special equipment required for installation;
  • The minimum height is 40 millimeters. For rooms with low ceilings, this is critical.
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The dry screed technology is gaining more and more fans thanks to an impressive list of advantages:

  • It manifests itself well in operation in various types of premises, from living rooms in an apartment to outbuildings in the country. This is achieved due to the fact that the dry backfill is porous and resistant to freezing;
  • The lightest of all screed types. The low weight of the entire structure allows the use of the screed even on weak floors;
  • More suitable for leveling wood floors;
  • Copes with the most difficult types of floors;
  • In the process of work, excess dust and dirt does not appear;
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  • You can do the screed with your own hands;
  • The mixture does not freeze, so the procedure can be interrupted and started over;
  • The components are of natural origin, harmless even in the nursery;
  • Can be easily combined with different types of floor heating systems;
  • No special equipment is needed, only beacons and guides that are included in the kit from the manufacturer;
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  • Almost does not settle, does not crack;
  • Maximizes the level of sound insulation and prevents heat loss;
  • Drying and shrinkage time - up to 4 days, then you can continue the repair;
  • The top sheet material makes the sub-floor surface perfectly flat;
  • The service life is over 20 years.
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The technology is also not without its drawbacks:

  • Dry backfill is not a monolithic formation. With an insufficiently dense layer, larger abrasive particles rise upward, and small ones settle downward, which makes the screed "shrink";
  • When combined with a warm water floor, there is a risk that the pipes will narrow and heat up too much, this will lead to their displacement, since it does not give rigid fixation;
  • When using flooring without a stabilizing layer (carpet and soft), significant point loads can make the screed uneven;
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  • On earthy surfaces, it requires an additional layer of insulation;
  • Abrasive particles wear out;
  • Many types of dry backfill are hydrophobic;
  • Organic matter is an excellent breeding ground for fungi and bacteria. If the screed gets wet, problems may appear over time.
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Factors influencing the choice

The choice of a suitable screed is governed by a number of conditions. First of all, the type of premises is important: a private house or apartment, the first floor, or from the second and above, in the house you need to insulate the floors or in the utility room.

Any type of screed is suitable for the first floors, if it is floating, since this floor is the coldest and the risks of condensation under the floor are the highest here. Concrete and cement screed, expanded clay fillers and variations from vermiculite and polystyrene concrete perform well in operation.

PVC film works best as waterproofing, and mineral wool can serve as a heater.

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Next, you need to evaluate the type of overlap. Concrete slabs easily coexist with concrete, cement, expanded clay, various slags and plasticizers. But the boards are more capricious in the choice of material for the screed. Liquid mixtures based on cement, concrete and water may be too heavy for them and oversaturate the wood fiber with moisture. Such a screed will dry for a very long time.

Affects the choice of the purpose of the screed. If this is only leveling the floor, you can limit yourself to concrete. Backfill is suitable for insulation. Sound insulation will improve in any of these cases.

An important role is played by the operational condition of the floors. Strong constructs will withstand a mass of liquid and semi-liquid screed, but for the weak it is better to choose a dry screed or bulk mixture.

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It does not hurt to take into account the maximum difference in floor height. The concrete screed is capable of leveling up to 50 millimeters, the rest have less indicators. The most even floor without serious defects has a dry screed, and different types of backfill, and a prefabricated slab, and quick-drying gypsum, and a bulk mortar.

When choosing rooms for various functional purposes (kitchen, recreation area, bathroom and others), one of the main criteria is moisture resistance. The leader among the types is a solid screed, in second place is a dry screed, and is most susceptible to a humid microclimate, which means that a dry screed is less suitable. The exception is cement and wood fiber sheets. Such plates are not considered hydrophobic.

A less common reason to favor one or the other is time resources. If the repair is urgent, then the best option is a prefabricated screed made of plate material. If there is a time from a week to a crescent, it is important to use a semi-dry and dry screed. When the deadlines are not tight, you can spend time installing wet. It will take a month or more, taking into account the time for complete drying.

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Financial capacity is also important. The estimate should take into account that in case of "wet" work, you will need to purchase or rent a special device, equipment and hire workers. Plus material costs. With a semi-dry screed, the costs are similar. A dry screed does not imply such difficulties, the work can be done independently, but the materials are supplied to the market by the monopolist brand, and the complete set will cost a round sum.

Of course, you need to pay attention to the advantages and disadvantages, strength, performance in the documentation and the availability of the documentation itself.

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Careful study of the issue will save you from mistakes in choice and possible problems in the future.

Process features

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Distinctive features of technologies are in their name. Accordingly, a wet floor screed in an apartment implies working with liquid formulations and pouring, and a semi-dry and dry one - with friable substances.

Pouring of a continuous screed based on various cement-concrete-gypsum combinations, sand and fibers occurs in several stages:

Dismantling work. They involve a thorough cleaning of the rough surface. It must be removed from construction debris, and the cracks must be sealed with putty. Not to the absolute ideal, but the cleaner the floor, the better the grip will be

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  • Overlap treatment with a primer. The primer increases the biostability and improves the bond between the floor and the screed;
  • Marking the walls. Here, a laser level is used so that the lines are strictly horizontal, and the surface of the screed is as even as possible.
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  • Laying of waterproofing PVC foil, if necessary. It can also be bituminous paper or other sheet material that overlaps up to 25 centimeters. The edges should fit into the wall. Waterproofing is necessary in damp and cold rooms, and can also protect against leakage of the liquid mixture to the lower floor.
  • Installation of damper tape. It is glued over the lower edge of the wall along the entire height of the leveling layer before it is poured. The edge tape fixes the waterproofing material.
  • Installation of thermal insulation materials, if necessary.
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  • Installation of beacons. Lighthouses are like a metal mesh with a large pitch. They are a guideline for calculating the thickness, surplus is removed from them and the surface is leveled.
  • Preparation of the solution. The choice of method depends on time, skills and financial capabilities.
  • Fill. Start correctly from the wall opposite the doorway. The solution is laid out in portions and aligned with the beacons. After pouring, it must be left for 4 weeks until it dries completely.
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The self-leveling floor technology is somewhat simpler, but is suitable only for the most even surfaces.

It includes the following steps:

  • Cleaning and degreasing the floor area. There should be no dust, traces of paint, grease stains and other imperfections that interfere with the high-quality adhesion of the mixture to the floor.
  • Primer. Concrete contact is also suitable. These substances give the subfloor a rough surface for good adhesion and protect against the appearance of fungi and microorganisms.
  • Creation of a suitable indoor climate. The room is insulated from drafts, the comfortable temperature for the mixture to solidify is 5-25 degrees.
  • Dilution of the mixture in a large container using water and a construction mixer. The consistency should be uniform, without lumps, not too runny.
  • Applying the mixture to the floor surface. This is done with a long-handled needle roller and a spatula. The mixture is poured out in portions and "rolled out", and then independently takes the desired shape.
  • Drying period - up to 2-3 days.
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Semi-dry screed technology, like other types, can be with or without reinforcement. Reinforcement involves the installation of a mesh to stiffen the screed. Installation of additional layers can also be carried out to stabilize the mixture, waterproofing and soundproofing.

There are several distinctive features in the process of work. It is recommended to carry out the first few steps in the same sequence as for a wet screed: surface preparation, priming, reinforcement (if necessary), installation of a damper tape, mortar preparation.

In order to prepare and serve the solution, a special technique is required, therefore it is difficult to perform a semi-dry screed without the participation of professionals.

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When the solution is ready, you need to start laying it right away. The first layer is 15-20 mm, then a reinforcing mesh is placed on it. It is optimal to weld mesh fragments together, but wire can also be used. Then another 20-40 mm of solution is poured. If it contains fibers, there is no need for reinforcement.

Then the surface of the solution is leveled along the beacons. This requires beacons, guides or drywall sheets, a laser level, and a tool called a rule.

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The next stage is grouting the mortar. It occurs at the moment when the mixture "grabs" a little and the profiles can be removed from it. The traces from the profiles are filled with mortar, and then the entire surface is sanded with a construction grinder.

Screed maintenance is also part of the process. It is not enough just to leave it on for a few days until it dries completely. Since there is not too much water in it, it evaporates very quickly and the screed may harden incorrectly. To prevent accelerated evaporation, it is covered with polyethylene on top or a humid microclimate is created in the room. The screed dries from 4 days.

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The technology of prefabricated or dry screed is fundamentally different from the previous types. It consists of a large number of layers, each of which is important and necessary and affects the quality of the floor.

The work progress is carried out in the sequence recommended by the manufacturer:

  • Preparatory work. The floor surface is dried, dedusted, treated with a putty solution in places with pronounced cracks and defects. The joints between the ceilings and at the joints between the walls and the ceiling must be sealed with a soft material, for example, mineral wool.
  • Primer. This step is necessary when working with bulk materials, since they are of natural origin and are more susceptible to the appearance of living organisms and fungi than others.
  • Leveling layer. Not always required, but only in cases where the overlap is in very poor condition. Height differences, chips and problem areas that dry backfill cannot level out are treated with cement mortar or a mixture for self-leveling floor. The hardened even layer needs secondary preparation: dust removal, primer.
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  • Determination of screed height using laser or water level.
  • Installation of waterproofing and vapor barrier materials for those rooms where it is impossible to influence the high level of humidity. For a concrete, block, cement base, a film layer is used, laid with an overlap and overlapping the wall. For a wooden floor, bituminous paper or paraffin paper is more suitable. A part of the insulating material that extends onto the wall to the entire height of the future screed is pasted over with edge tape. This simultaneously holds the sheets and protects the walls from cracking.
  • Heat insulation and sound insulation. Includes installation of sheet material, but is not always required. The dry backfill layer itself is an insulating agent.
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  • Installation of beacons and barriers at the exit from the room (at all doorways, if the room is through). The backfill has a "fluidity", therefore, at the border of the premises, temporary sills are installed according to the level of the screed height. Beacons and guides are installed according to the scheme.
  • Backfill. There are no strict rules for laying abrasive material, but it is important to observe the density recommended by the manufacturer per square meter and level it at the same time as filling the material. In the design of the beacons, a rail is provided for this, which "walks" along the guides and levels the top layer of the screed.
  • Installation of overlap. The peculiarity of dry backfill is that it must be covered from above with sheet material in 1 or 2 layers in order to reduce point loads and subsidence of the substance. Layers of gypsum fiber sheets are interconnected with mastic and screws. Seams are rubbed to a smooth surface. Then you need to leave the screed for natural shrinkage. Drying time is approximately 3 to 5 days.
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Materials and tools

All the necessary equipment and materials used can be divided into two groups: universal (necessary for any type of work) and specialized (for a specific type of screed).

Versatile materials and tools:

  • Devices for dismantling old finishing materials. The set itself can be different, from a nail planker for removing a plank floor to a paint and varnish destroyer B52. You may also need a spatula to remove old paint, brushes, and a blow dryer. The tiles usually have to be chopped or removed in parts. This requires a hammer drill, chisel, or metal hooks. In a new building, private or multi-apartment panel building, things are easier. From the floors, you just need to remove debris, dust the working surface with a construction or ordinary vacuum cleaner and wash it with water and soap.
  • Don't forget about safety precautions. Installation work takes place in dusty and dirty rooms, and small fragments of tiles or paint solution can damage the skin of the hands, so work equipment is needed - closed clothes, high heel shoes, rubber and cotton gloves, a respirator and plastic glasses.
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  • Primer compounds. For concrete floors, concrete contact is excellent, for wooden floors - a universal primer and a liquid for processing wood. The primer is applied with a paint brush (better than a synthetic one, it absorbs less of the product) or with a roller.
  • One of the first tools required is the building level. Levels can be of different types: flask, water, laser. The most accurate is the laser level, but the bulb can be quite accurate in the hands of a professional.
  • The associated tool is a metal profile or plaster beacon. It can also be made of wood. An alternative option for a purchased lighthouse is cement-sand beacons, which are made independently and are placed around the perimeter of the room. But this option, in order to save money, is only suitable for those who have extra time to wait until they dry. The approximate period is 3 days.
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  • If it is necessary to install additional layers, the list of materials and tools is replenished with foil and insulation sheets. PVC, bitumen paper and other waterproofing layers are purchased in rolls based on floor area plus 25% for overlaps. They are connected to each other with mounting tape. Insulating layers are also sheet or slab. A sharp construction knife is used to cut the material into fragments.
  • A required element is a damper or edging tape. It is easier to cut it with scissors, so it's better to stock up on them in advance.
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  • Aluminum rule. It is a lightweight, durable, handy tool needed for spreading and leveling a liquid or semi-dry mixture. Such a device is inexpensive, but it copes with leveling the screed surface better than any other tool.
  • Plaster trowel or trowel. It is necessary to grind the screed surface in order to achieve maximum smoothness.
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In addition to patience (screeds dry for about a month), specialized materials and tools for wet and semi-dry varieties will be required:

  • Ready mix in liquid form and a concrete pump for its delivery, ready-made dry mix and water or dry components for mixing and dilution with water;
  • Capacity from 30 liters in volume, measuring container for water;
  • Grinder;
  • Construction mixer. A drill with a nozzle for mixing liquid substances is also used.
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Self-leveling floor accessories:

  • Calculator for mathematical calculations to accurately determine the consumption of a substance per square meter. If, in the case of cement, the exact value is not critical, then the self-leveling floor is too expensive to overpay for the extra kilograms of the mixture;
  • Container with high walls;
  • Electric drill with mixing attachment;
  • Notched trowel from 50 to 100 cm wide for leveling the screed surface;
  • Needle roller with long handle. It simultaneously helps to distribute the composition over the floor surface and pierces the bubbles formed in the mixture.
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The necessary set of additional tools for the installation of a dry screed:

  • Joint processing material: wood fiber, mineral wool, mounting tape;
  • Backfill material. One of the most common is expanded clay concrete. It allows you to avoid unnecessary spending on materials for the installation of thermal insulation and noise insulation in the room. The approximate material consumption is 40 liters per square meter, and the weight of the screed is 3 times less than wet or semi-dry;
  • Sheet material for leveling the surface. Usually it is gypsum fiber;
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  • Mastic or glue for gluing gypsum fiber layers;
  • Spatula for removing excess mastic;
  • Drill and self-tapping screws.
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How thick should it be?

The leveling of the floor does not take place by eye. The thickness and density of the screed are calculated depending on the condition of the floor and the desired result. It is also worth considering the type of room, soil, the presence of a heated floor contour and its type, maximum loads on the floor surface.

There is no screed less than 20 millimeters in height. This is the minimum value for leveling and self-leveling mixtures, suitable for different types of premises and combination with an electric underfloor heating up to 5 mm.

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The minimum height that can be filled with liquid mixtures is 3 mm. Otherwise, it will just crack. A layer above 40 mm is needed for rooms with high loads and high traffic. It is better to reinforce such a screed, then its height will be from 5 to 7 cm. It also adds centimeters and additional insulation. And if the PVC film is only 1 mm, then polystyrene concrete is much thicker.

A screed less than 4 cm will be short-lived and fragile

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The thickness of the screed for leveling the surface above the contour of the water-heated floor can be up to 10 cm. In this case, it is permissible to use wet and semi-dry screeds only if the floors are in excellent condition. If their operational assessment is in doubt, it is dangerous to fill such a floor with cement, sand concrete or gypsum. It is worth giving preference to the dry version. Lightweight filling weighs 3 times less, so its layer can reach 10-15 cm. The exception is the floor in the "Khrushchev". In buildings of this type, the ceiling is rarely high enough, so you should limit yourself to the minimum screed thickness.

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Surface preparation

The preparatory stage of work on the screed device is important. A universal building material - penoplex - helps to reduce the number of actions for insulation, priming, leveling and protection from moisture of the working surface. Penoplex is called cellular polystyrene, which is of several types: for roofs, walls, floors, outdoor spaces.

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All varieties have similar advantages:

  • Low weight;
  • Porous structure;
  • Increased strength;
  • Resistant to moisture;
  • Prevention of heat loss in the room;
  • Long service life.

Mounting the foam on the work surface simplifies the pouring of the screed or the formation of a bulk layer, since the subfloor becomes as even and suitable for installation as possible.

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Beacon system and reinforcement

These are two procedures independent of each other. But if reinforcement is not always needed, then the installation of beacons is an obligatory stage in the device of any type of screed.

Reinforcement is, in fact, a lining of a metal net in the body of the screed, which protects the heating system from the severity of the leveling layer of the floor, prevents it from cracking and increases its strength.

It is necessary when the screed is floating (done when the floor is close to the ground), there is no fiber in the composition and the layer thickness exceeds 4 cm. In other cases, the procedure can be avoided.

The lighthouses are installed directly on the reinforcing mesh. There are two types: slats and benchmarks.

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Reiki, in turn, is divided into several types:

  • Made of wood. This is an affordable and easy-to-use type of beacon that has several features. Firstly, it must be well soaked in water before use so that the tree does not absorb moisture from the screed itself, and secondly, the tree must be removed, otherwise it will rot inside the cement layer over the years;
  • From the profile. "Plaster beacon" is suitable for pouring or backfilling screeds up to 30 millimeters. With a greater thickness, it will simply bend under the weight of the screed and cease to perform its function;
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  • From the pipe. They can be round, rectangular, square. Used for installation in large areas for thick screeds;
  • From the solution. The base of the lighthouse is made up of a steel thread, which is held by self-tapping screws. A solution is applied on top of the thread, which subsequently becomes a guideline in a straight line;
  • From a solution in the form of a slide. Such landmarks are placed along the entire perimeter of the floor at the same height. The width between them must not exceed the width of the aluminum rule. That is, the minimum is 50 cm, the maximum is 100.
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Preparation of the solution

There are 3 proven ways to obtain a solution:

  • Delivery of ready mix to order or making it by professionals before starting work. In this case, the mixture is prepared outside the home. All bulk components and water are mixed in construction equipment, which combines the function of a concrete mixer and a concrete pump. The ready mix is fed through large-diameter hoses up to the height of the third floor. This eliminates the need to carry heavy containers with the mixture home, makes the work cleaner, and the mixture hardens more slowly. But this is the most expensive and time consuming method. It is necessary to pay for the services of the construction team and the rental of equipment.
  • Purchase of dry mix. Cheaper than the first option, but for its preparation you will need a large container and a construction mixer. The mixture needs to be mixed from time to time, as it hardens quickly. To slightly extend the time at which it will remain liquid, a film covering the top of the container with the solution will help. In the finished form, a mixture for a liquid screed and a dry-pressed mixture are purchased. Dry backfill made of expanded clay, expanded polystyrene concrete, various mixtures with foam concrete are also sold in bags, but they do not need to be diluted with water at all.
  • Purchase all components separately and preparing the solution with your own hands. This is the cheapest and most difficult option, since you need not to miscalculate with the components for the composition, their ratio and the total volume of the mass. The hardest part here is choosing clean sand and fiber reinforcement. But with the right combination, such a screed does not differ in quality from the factory mix.
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Fill

Filling is done manually in most cases. A still wet mixture must be leveled with a roller (if it is a self-leveling floor) or with an aluminum rule, and then rubbed with an assembly trowel. For semi-dry screeds, special machines are provided.

In an apartment, country house or cottage, a high-quality screed is needed so that in the foreseeable future this complex procedure does not have to be repeated during repairs.

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With the most even floor surface, several tasks are simplified:

  • The floor level becomes a reference point for marking various objects, for example, sockets and switches;
  • Finishing is simplified. Laminate, parquet, tiles, soft flooring perfectly fit on a flat screed;
  • Furniture and appliances are exactly worth it;
  • In the case of a self-leveling floor, the screed is already a decorative finish.
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Care Tips

Caring for the floor screed comes down to one important procedure - do not let it dry out, otherwise the surface will crack.

To do this, it is important to follow several rules:

  • Do not create drafts in the room;
  • Observe the temperature regime from 5 to 25 degrees;
  • Do not put stress on the screed;
  • Spill it with water from time to time;
  • Cover with plastic wrap.
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Testimonials

The floor screed is unanimously recognized as an integral part of the structure of the room. Among the advantages, users note that the floor becomes very even, the finishing material easily falls on it, noise is muffled, it becomes warmer and more comfortable in the room.

There are also negative reviews. Among them are the laboriousness of the work, the high cost of some materials, the coldness of the concrete floor.

How to correctly make a cement-sand screed, see below.

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