Flooring manufacturers claim that the durability of their products depends on the condition of the subfloor. If there are limitations for classic cement-sand leveling, then the time-tested dry screed technology is used.
According to SP 29.13330.2011 / SNiP 2.03.13-88, the base for decorative and protective materials must be rigid, even, durable, monolithic. The following technologies are used to eliminate defects:
- Classic mineral screed of "wet" type from cement-sand, gypsum and other types of solutions. This also applies to the bulk floor.
- Semi-dry leveling of the subfloor using a mixture of sand concrete and fiberglass.
- Dry screed - prefabricated flooring on the base base or ceiling.
Let's stop at the last one. The technology involves alignment using sheet building materials such as GVL, LSU, chipboard, plywood, OSB and others. There are even special sheets MDF and cork composite used in combination with special purpose finishing materials.
Dry screed should be preferred in cases where:
- It is required to speed up the work as much as possible;
- "Wet" processes are undesirable;
- The room has strong drops, irregularities, or it is necessary to significantly raise the level of the existing floor.
Experts have developed several design options. For apartments, houses and offices, the following types are most often used:
- Frame floor (on logs).
- Adjustable design.
- Hard subfloor.
Consider each type with all the advantages and disadvantages in more detail.
Bulk floor screed
This type of prefabricated flooring is most actively promoted on the Russian market. Recommended for use on slab and beam types of floors.
Bulk screed is a multilayer structure consisting of:
- A waterproofing film laid on a base with an overlap on the wall. It is strongly recommended to use it to prevent the penetration of fine suspension and dust into the lower rooms, as well as a shut-off steam and moisture barrier. Since the layers on top provide air sound insulation (that is, they level out the sounds of human speech, TV, etc.), experts advise taking care of impact noise reduction as well. Especially in cases where it is planned to lay coatings with a resonance effect (laminate, parquet board etc.) To do this, rolled or slab vibroacoustic materials are mounted under the waterproofing;
- Nonmetallic backfill. It can be crushed or fine-grained expanded clay, expanded perlite, crushed slag, slag pumice, vermiculite mass, silica or quartz sand and other types of fillers. The recommended granule size module is from 0 to 7 mm, moisture content is not more than 1%. Backfill thickness - from 20 to 100 mm;
- Sheet building materials. Preference should be given to grooved products like Knauf-Superpol (GVL) with a mounting seam 50 mm deep or tongue-and-groove chipboard from QuickDeck. As an analogue, the use of plywood, OSB, DSP and others is allowed.
For non-load-bearing or light-duty areas (e.g. attics, summer annexes, relaxation rooms, etc.), some manufacturers suggest the use of edge-to-edge slabs of extruded polystyrene foam or high-density mineral wool.
Table 1. Bulk dry floor screed: pros and cons
| Positive traits | Negative characteristics |
| Light weight compared to classic mineral screed. | In the absence of experience, mistakes are not uncommon, which entail many problems (squeaks, bumps, dust, etc.). |
| High speed of work - from 1 day or more, depending on the area and complexity of the object. | Over time, partial shrinkage of the backfill is possible, as well as the appearance of the “hourglass” effect due to uneven loading, dynamic movements, etc. |
| Low level of dust during installation. | Weak sound insulation, especially for structural and impact noise, which requires an additional layer. |
| Sophisticated equipment (concrete mixers, etc.) is not required. | Service life according to component manufacturers is 5-10 years. |
| Do-it-yourself styling is allowed. | |
| High level of thermal insulation. | |
| Maintainability and ease of dismantling. |
The technology of the bulk screed device at first glance seems simple, but in practice there are many "pitfalls" in this matter. Due to the lack of specific knowledge of the master after laying, various difficult-to-remove defects appear, such as:
- Raised corners;
- Lack of evenness, which is especially visible at the joints of the plates (when using products with even, non-grooved edges);
- The formation of voids under the flooring;
- Punching of some areas;
- Dust formation.
As a result - a violation of the integrity of the finishing finishing material, multiple squeaks, etc. But the cost of installing a bulk screed is considerable - a full cycle from about 900 rubles / m².
Briefly leveling the floor using non-metallic materials is as follows.
table 2. Laying dry prefabricated flooring using backfill.
| № | Process name | Scheme |
| 1. | Substrate preparation: removal of old coatings, cleaning of debris, partial leveling. |  |
| 2. | Checking the floor with a level, marking the walls. |  |
| 3. | Laying a polyethylene film to provide hydro- and vapor barrier with an overlap on the walls of about 10–20 cm. If necessary, vibroacoustic materials are laid up to the polyethylene film. |  |
| 4. | Fixing the damper tape around the perimeter. |  |
| 5. | Backfilling of non-metallic filler, its alignment with the help of guides and a leveling rail. Compulsory tamping and re-smoothing of the surface to obtain a dense layer without shrinkage and movement. |  |
| 6. | cutting GVL sheets or chipboard, laying from the far wall with the end joints offset in adjacent rows by at least 25 cm. For grooved floor elements: “liquid nails” glue is applied along the edges, and hardware is also screwed in to ensure the solidity of the flooring. |  |
| 7. | Seal joints with elastic putties. |  |
| 8. | Under ceramic and stone slabs, additional treatment with moisture-proof primers is recommended. |  |
Dry screeds also include a frame system, better known as a floor on logs. From the name it is clear that the structure is a "skeleton" of rails or metal profiles, fixed in increments of 40–50 cm to a concrete or wooden base. For alignment under the frame elements, linings made of fiberboard, chipboard, wooden bosses are placed.
The existing frames are attached to the prepared frame. sheet materials: OSB, chipboard, MDF, plywood, etc. The finished subfloor is suitable for any floor materials, including laminate, parquet, tiles made of natural or artificial stone, and with high-quality processing of joints - under linoleum, carpet and other types of elastic and semi-rigid finishing materials. Since its strength does not exceed 15 MPa, a lag floor should be installed in rooms with a non-intensive load: private houses are frame, panel, monolithic, block, wooden; apartments, offices, small cafes, etc. The cost of such a floor starts from 1100 rubles / m².
Table 3. Advantages and disadvantages of the floor on the logs
| pros | Minuses |
| Relatively small weight in contrast to the "wet" screed. | Labor intensive installation process. |
| Possible self-laying in dry and damp areas, including bathtubs and laundries. The latter require waterproofing or the use of moisture-resistant sheet materials. | A decent height of the structure is from 5 cm to 15 cm. |
| Perhaps the device of a water heat-insulated floor and "soft" electric heating of the basis. | If the technology is violated, squeaks, subsidence, floor dents, geometry violations and other defects appear. |
| Easy dismantling and maintainability. | The maximum floor strength level is up to 15 MPa. |
| High level of sound and heat insulation. | |
| If the technology is followed, the service life is at least 10 years. |
The method of arranging the floor on the logs has long been worked out and is successfully carried out both by professionals and with their own hands.
Table 4. Installation of a frame dry screed.
| № | Process name | Scheme |
| 1. | Substrate preparation: cleaning of old flooring, debris, elimination of strong drops, ledges, filling pits and potholes with repair quick-drying compounds, waterproofing, soundproofing. |  |
| 2. | Checking the base with a laser or hydrolevel, if desired, marking. |  |
| 3. | Treatment of wooden floor elements with protective compounds. |  |
| 4. | The formation of the frame from the lag. |  |
| 5. | Laying in the gaps of the heat insulator. |  |
| 6. | Installation of sheet materials using screws, nails and other types of hardware. |  |
| 7. | Final polishing of the floor. |  |
When using industrial heaters, it is desirable to carry out work in accordance with the manufacturer's instructions. For example, if applied mineral wool, then under the logs it is necessary to lay a steam and windproof membrane. And after the installation of stone or glass wool slabs - vapor protection flooring. And only then - fixing sheets of plywood or chipboard.
Adjustable floor
The third type of dry screed is reasonably considered the most time-consuming to perform, requiring professionalism and the ability to solve non-standard tasks from the master. At the same time, the design is in demand, as it allows you to correct shortcomings both in new buildings and in the reconstruction of old facilities.
Structurally, it consists of wooden logs or plywood / chipboard sheets, which are installed on fastening and supporting elements screwed into them. As the latter, threaded rods-racks, bolt-racks, anchors and other similar hardware are used. The height of the supports is adjusted by rotating the locking bolt around the cantilever axis. To fix the position of the floor element, special stops, dowel-nails are used. The cost of arranging such a rough base is from 1200 rubles / m².
Table 5. Adjustable prefabricated deck installation.
| № | Process name | Scheme |
| 1. | Preparation of the base floor: removal of debris, large floor defects, waterproofing if necessary. |  |
| 2. | Checking the base with a level and deriving the level of the future floor. |  |
| 3. | Installation supporting elements(brackets, anchors, etc.). |  |
| 4. | Installation of intermediate logs, insulation or laying plywood sheets on adjustable hardware, fixing them. |  |
| 5. | Checking the finished flooring, removing protruding elements, if necessary - grinding the surface. |  |
Adjustable floors are applied on mineral and wooden bases, including crumbling, fragile, and also with low bearing capacity. In addition, they have many other advantages.
Table 6. Advantages and disadvantages of an adjustable floor.
| pros | Minuses |
| Possibility of alignment of any, even the most difficult bases. | If the technology is violated, various defects quickly appear: squeaks, bumps, etc. |
| Relatively light weight and low load on load-bearing structures. | The process requires professionalism from installers, as well as considerable labor and time costs. |
| It is allowed to lay any communications under the flooring. | Not suitable for rooms with low ceilings. |
| Device for additional heat and sound insulation. | |
| If necessary, a quick change in floor level is possible. | |
| Suitable for almost all floor finishing materials. | |
| Service life - not less than 7 years. |
Rigid dry screed
The last type of dry prefabricated flooring is also formed from chipboard, GVL, OSB and other analogues. It is considered the easiest to perform, since all sheets are installed directly on a concrete base without additional linings. Recommended for leveling the surface of floor slabs or after the installation of a traditional cement-sand screed. Eliminates minor defects and provides minimal thermal insulation under laminate, parquet, linoleum, carpet and others Decoration Materials.
Table 7. Strong and weaknesses hard flooring
| Advantages | Flaws |
| Simple and fast installation. | If the technology is violated, squeaks and small irregularities may appear. |
| Light weight design. | Aligns only minor defects, that is, differences of no more than 5 mm. |
| It is allowed to install “soft type” underfloor heating systems (infrared mats, rod sets) under a laminate, parquet board. | Additional thermal insulation is not possible. |
| Suitable for all finishing materials, but when laying tiles or stone, sheets of a moisture-resistant series are required. | |
| Service life - not less than 10 years. | |
| Optimal for rooms with low ceilings, as well as any level of loads. |
Installation of a rigid dry screed is simple. To do this, sheets of plywood, chipboard, DSP in 1–2 layers are fixed on a clean, prepared base with the help of hardware or polymer adhesives. The thickness of the finished coating is 12–24 mm. The price of the flooring device is from 300 rubles / m².
Table 8. Dry screed installation.
| № | Process name | Scheme |
| 1. | Substrate preparation: removal of construction debris and dust. As well as the elimination of tubercles, filling potholes, pits with repair compounds. Waterproofing or treatment with reinforcing soil is done at the request of the customer. |  |
| 2. | Checking the evenness of the floor level. |  |
| 3. | Flooring of sheet materials and their fixation with hardware. |  |
| 4. | Sanding the floor to smooth out the smallest differences along the edges. |  |
Comparison of classic, semi-dry and prefabricated screed
All types of dry floor leveling are effective, convenient and fast way bringing the base to a condition. In addition (with correct device!) a wonderful alternative to wet and semi-dry types of screeds. Each of them has its own goals, tolerances and limitations. Let's compare all three technologies in a tabular format.
Table 9. Comparison of types of screed work.
| Characteristic | Classic cement-sand screed | Semi-dry leveling | Dry prefabricated flooring |
| Compatible with floor finishes. | Everything | Everything | Ceramics and stone require waterproofing. |
| The term for the performance of work for a room up to 100 m 2, from the beginning to full operation. | At least 30 days. | 1–2 weeks. | 2–5 days. |
| Application for rooms with increased level humidity. | Yes | Yes | Limited |
| Device in buildings with normal level loads. | Yes | Yes | Yes |
| Limited use due to low ceilings. | Yes | Yes | Not |
| Formation in rooms with intensive loads. | Yes | Yes | Not |
| Restriction for the device due to weight. | Yes | Yes | Not |
| Price (for a full cycle). | From 1000 rubles / m 2 | From 1100 rubles/m2 | From 300 rubles/m2 |
| Life time. | 10–30 years | 5–15 years | 5–15 years old. |
According to customer reviews, the classic cement-sand screed is still considered the most durable and durable. All other types of leveling are recognized by the owners of apartments and houses as not so reliable, but quite effective and convenient for laying flat floors for laminate, linoleum, parquet, and tiles. As the analysis of the situation shows, a kind of wave of negative opinions associated with a dry and semi-dry screed is caused precisely by multiple violations of the technology of their construction. Therefore, taking into account the experience of others, carefully approach the selection of repair teams and be sure to control the process at all stages.
Advice! If you need repairmen, there is a very convenient service for their selection. Just send in the form below detailed description work that needs to be done and you will receive offers with prices from construction teams and firms. You can see reviews of each of them and photos with examples of work. It's FREE and there's no obligation.
Making a wet floor screed with your own hands is time consuming, but not difficult. We consider the features of this work in today's article.
It is necessary to immediately clarify that in the following presentation we will call a layer of material laid on top of the floor a screed.
It solves two problems:
- Levels floors in different rooms.
- Makes the floor surface even and suitable for laying top coats - tiles, laminate, parquet.
Features of the "wet" screed
The vast experience of its manufacture and operation helps to see its features.
Advantages:
- Fits on all types of floors, including on the ground.
- Strength and durability.
- Suitable for any finishing finishing materials.
- Established technology.
- It can be performed over thermal and waterproofing.
Flaws:
- Big mass.
- Long "ripening" time - up to 90 days.
- Very long time drying - up to six months or more.
- Strength directly depends on the quality of materials and adherence to technology.
The disadvantages of a “wet” screed are relative and are offset by the predictability of the result.
There are two approaches. In the first case, the screed is made in the form of an independent part lying on the ceiling.
In another embodiment, it is necessary to achieve a strong adhesion of the screed to the base. She must become one with him.
The first option is required if you are doing your own. The screed plate must be able to "breathe" when the temperature changes. A damping tape is laid along the perimeter, and under it - a layer of thermal insulation.
In order for such a screed to have sufficient strength, it must be of considerable thickness. Masters avoid making them thinner than 8-10 cm.
In the second option, the screed can be thinner, but not less than three centimeters.
The main stages of manufacturing a "wet" screed
- Foundation preparation
- Installation of beacons
- Mixing and pouring
- fine-tuning
If you decide to make a “wet” screed yourself, you should figure out what kind of result you should get at each stage. Let's discuss this in more detail.
Preparation of the base for the screed
The base must be carefully swept. Remove dried pieces of solution. For laying thermal insulation on it, this can be limited.
If it is required that the screed firmly adhere to the base, the surface must be treated in good faith: sweep with a damp broom, prime with an acrylic primer, if necessary, with “concrete contact”. Separately, we check and close up holes and cracks, otherwise the solution will leak to the neighbors from below. All primers must dry completely.
Installation of beacons
Beacons are needed so that the surface of the screed is flat, horizontal and at the required height. The thoroughness in this matter cannot be overestimated.
For lighthouses, it is convenient to use galvanized drywall guide profiles. They have good rigidity. You can use plaster beacons with a thickness of 9 mm.
An experienced craftsman uses alabaster to install beacons: it quickly hardens. The best way- use gypsum plaster. It is plastic and convenient to set the beacons with an accuracy of a millimeter and will grab in an hour and a half.
fill
After the beacons are installed and fixed, start pouring.
The task will be greatly facilitated if you establish a kind of conveyor for the preparation of new portions of the cement mixture. The mixture must be homogeneous in composition and consistency. Excess water is very harmful.
Start from the far wall of the room and move towards the door. Level the surface of the screed according to the level of the beacons using the rule. The mixture will separate and release water. Do not leave puddles on the surface of the screed.
Filling work is tedious and dirty. Be prepared for this.
fine-tuning
After the screed is completely filled, give it a day to harden. Then remove the beacons and fill the furrows remaining from them with the same cement mortar.
Further work on the screed depends on what kind of finish will be laid on it. If the tile, you can stop there.
If a smooth surface of the screed is required, it can be rubbed with a grater with the addition of fresh mortar. Or make a thin self-leveling floor.
You can start walking on a freshly laid screed in a day, but for complete hardening, you need to withstand it for at least 28 days at normal temperature. Only after that you can start laying ceramic tiles on it or drilling plywood for parquet.
Note. We are talking specifically about the hardening of the material. Its speed does not depend on the layer thickness and humidity. At lower temperatures, hardening slows down. At 10 degrees Celsius, it will go twice as slow.
Drying the screed is a different process. The thicker the layer, the longer it will dry. High humidity and low temperatures slow down drying. For styling ceramic tiles residual moisture of the screed is not of fundamental importance. But for parquet - this is the number one factor. It will take at least six months to dry the screed.
About tools
To work, you will need very simple tools:
- Primer brushes.
- Two or three buckets with a volume of 20 liters for the preparation of the solution.
- Powerful electric mixer.
- Spatulas.
- Level.
- Rule.
About materials
The strength of the resulting screed depends on the quality of the materials. If you intend to make a mixture of sand and cement, pay special attention to the sand. The slightest admixture of clay will ruin everything. The quality of cement is more difficult to check, but low-quality cement is less common.
It is more convenient to use ready-made cement-sand mixtures from reliable manufacturers. Read the information on the package.
- You can make a screed in the bathroom alone. A large area needs to be filled with an assistant.
- If the screed needs to be done in an apartment building panel house, identifying and repairing all cracks, crevices and holes in the ceiling is a big problem. It is easier to cover the floor with thin polyethylene. Raise its edges to the walls by 20-30 cm. You will get a kind of bath for the working mixture - not a drop will leak to your neighbor.
- As a filler, it is very effective to add crushed expanded clay (bedding). It reduces the consumption of the mixture, takes away excess water, and then gives it away during hardening - the screed does not need to be watered. Additional advantages: the weight of the layer is reduced, the screed with an admixture of bedding never cracks. Add bedding no more than 30% by volume.
- Thoroughly mix each portion of the mixture. Careless mixing reduces the strength of the hardened material.
- If there is any doubt about the quality of the dry mix, mix one or two handfuls of pure Portland cement into each batch.
- Do not use ordinary expanded clay as a filler - it floats to the surface.
In conclusion, we repeat: making a wet floor screed with your own hands is not difficult at all. Take on this job. The reward for you will be saving decent money on the services of workers.
It is difficult to independently determine which floor screed is better. If 10 - 20 years ago only cement-sand was used, now a lot is known various kinds 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 she be?
Floor material, or rather the way it is laid, implies compliance with certain requirements for the base during implementation.
This applies directly to the surface on which the finish coating will be mounted. In general, when performing a screed, it is important to consider the following points:
- the area must be flat and leveled horizontally. Deviations not 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.
- Improve surface quality.
- Create good warmth, - hydro and - sound insulation.
Any of the types are good, but you can get the best result by completing the necessary list of works using different technologies and materials.
Wet screed
For a wet screed, crushed stone or gravel filler is used.
With a complete analysis of the question of which floor screed is better, you can start with the wet pouring method. It is made on cement, therefore there are only 2 options: concrete and cement-sand screed.
The difference between them is that the first method requires a filler with a large structure: crushed stone or gravel. The rest of the details 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 a concrete and cement-sand base, 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 finish screed. In addition, large-scale capital construction is carried out with its help.
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Its wide popularity is due additional features composition:
- The wet screed of their concrete is poured and hardens much faster than the cement-sand screed.
- When processing large areas, the total cost is much less than dry or semi-dry.
- It is allowed to make a layer of any thickness, which involves the use of concrete for leveling almost any curvature of surfaces.
The hardening time of the mixture also depends on the thickness of the layer.
Mortar analysis can reveal several disadvantages inherent in this method. First of all, this is a mandatory reinforcement of the structure. In addition, there are a number of reasons why many prefer other methods:
- long hardening time of the mixture, depending on the thickness of the layer;
- significant shrinkage and possible cracking;
- the flooded base must be constantly monitored and periodically moistened;
- laborious process self-produced mixtures;
- sufficient complex alignment of the horizontal direction of the surface.
The completed base is quite heavy, which contradicts the requirements for pouring the screed into apartment buildings, and in private ones it will lead to an additional load on the foundation.
Semi-dry
A 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 that of which the wet screed is made.
However, the mixture differs in the level of moisture content. Based on the name, the amount of water in this case should be added half as much.
An example is the composition for the manufacture of a mixture in proportions of 1 to 3, respectively, of cement and sand. To do this, you need only 24 - 26 liters.
After the distribution of the material, it is rammed
Semi-dry screed is performed as follows. The composition is evenly distributed over the previously designated area. Laying takes place in several layers, where each is rammed.
Having reached the desired level, indicated by beacons, the excess is removed by the rule. Walking on the surface is allowed after 2-3 hours. At this time, you need to perform the final leveling and smoothing the base with a metallic brush.
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To conclude which floor screed is best suited in your situation, you need to take into account some features of a semi-dry mixture before a wet manufacturing method. First of all, it is possible to single out the period during which the compositions, which were mentioned a little higher, solidify. In addition, there are several other distinctive features:
- High density semi-dry method.
- No reinforcement required.
- Shrinkage occurs during the drying process.
- Such a screed is mounted much easier, the installation of the finishing layer is allowed, on which, immediately after complete drying and hardening, a decorative coating is laid. For installation instructions for a semi-dry screed, see this video:
The disadvantages of the semi-dry method of pouring the screed relate only to the large weight of the structure and the impossibility of mounting in a thin layer. No others have been identified so far.
Dry
The technology by which the dry screed is installed differs significantly from the work required for wet and semi-dry installation.
For this case, sheet materials and loose heat insulator are used. The order of work is as follows:
- Wooden logs or slats are laid out on a rough screed or concrete base.
- After they are aligned in the same horizontal line, the elements are fixed to each other. The easiest way to use this metal corners for roof assembly.
- Expanded clay is poured between wooden lags.
- On the backfill, sheets of chipboard, OSB or plywood are laid, which are attached to the rails with self-tapping screws and glued together with glue.
Dry screed is quick and easy to install
Compared to the dry method, wet and semi-dry floor screeds are much cheaper, but this technology has its own advantages that are not characteristic of 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 of materials;
- when planning the installation of a floor heating system, it is considered the most acceptable option. The design is easily disassembled in the event of a malfunction in the system.
For this it is necessary
First of all, determine the zero level. If the workers do not have laser devices, then it is best to do this with a water level (spirit level). Linear, or rack - carpenter's level, is not suitable for this. The zero level should be “beaten off” immediately in all rooms, at an arbitrary height (the most convenient height is approximately 1.2-1.5 m from the floor). The technology is simple:
First, in an arbitrary place, the first mark is placed. Then, with the help of a water level, it is transferred to other parts of the wall, other walls and other rooms (with a laser device this is even easier). As a result, we get a lot of marks located strictly at the same level, relative to the horizon (and not relative to the existing floor). Separate marks are connected between
with a solid horizontal line. This line is considered the zero level, and will be used in the future to determine the horizontal plane, at all major stages of work. The zero level must be set exactly, and it is better to check it personally. This is needed later
in order to correctly set the level of the screed - from the highest point of the existing floor, and correctly calculate the consumption of the solution - according to the average thickness of the floor screed. To perform this operation
required to measure the distance from zero level, to the existing floor in different places of the room (the more such measurements, the better). At each measuring point, on the wall, with chalk, the value obtained is recorded. Most small value will point to the highest point of the existing floor. The largest - to the lowest. The difference between these values will indicate the level of elevation difference on the existing floor. Let's say that the minimum value is 1.22 m, and the maximum is 1.27 m. In this case, the height difference will be 0.05 m, or 5 cm. The minimum thickness of the floor screed in the apartment
from polymer cement (cement mortar with the addition of a plasticizer) should be 30 mm. If the layer is thinner, the screed will crack and crumble. Therefore, it is strictly not allowed to reduce the screed “to zero”! An exception to this rule is the leveling of the floor with special compounds (the so-called "levelers" or "self-leveling mixtures"). The minimum and maximum layer thickness in this case is determined by the manufacturer, for each specific composition. If your premises are to be used
several floor coverings, it is necessary that they outer sides were on the same level (the floors did not have drops and steps at the junctions of different coatings). Since different coatings have different thicknesses, it is necessary to plan the screed at different levels so that the height differences of the screed compensate for the different thicknesses of the coatings. Let's say that your apartment will use two floor coverings: parquet and ceramic tiles. Calculating the thickness of a pie might look like this
: It's in theory. In practice, it is better to slightly increase the difference
- a couple of millimeters. The thickness of the parquet "pie" is always fixed - there is nothing to add or subtract. And the thickness of the tiled coating can always be leveled a little - due to the thickness of the adhesive layer. Therefore, it is better to leave a margin of 2 mm. - in case the parquet "pie" lies a little higher. Usually builders buy for these purposes
ready-made dry cement-sand mixture, packaged in bags. Sometimes some additionally add cement and various plasticizers to it. Take an interest - which dry mix, specifically, the manufacturer your builders are going to use. If the first one that comes across on the market is no good. Dry cement mix can be very different in quality and price. The amount of marriage is amazing! Moreover, different types dry mixes are designed for different jobs. In the estimate, you can put a high-quality mixture at 90-120 rubles per bag, and pour third-rate material into the screed at 70-75 rubles. Taking into account the fact that for a screed with an area of 75-80 sq.m. it takes up to 100 bags of dry mix, then the “savings” are not bad - just pay for the delivery. But why do not you save, but for you? The normal color of the dry cement mixture is pure gray. The mixture should not have a yellow, brown, or red tint. This happens when there is an excessive content of sand in the mixture, or if low-quality sand was used in the preparation of the mixture, with an admixture of clay. It is not necessary to additionally add cement to a high-quality dry mix - this will only worsen its properties. It is also not recommended to use PVA glue instead of special plasticizers - cracking of the screed after drying is possible. All plasticizers should be added strictly in proportions specified by additive manufacturers. Before the device of a wet floor screed
it is necessary to properly prepare the base. To do this, the floor surface is carefully swept and inspected. Sometimes builders produce so-called. "iron" floors - coat the floors with "cement milk" - a liquid solution of pure cement. Before the device of a coupler this film layer needs to be removed since. it has poor adhesion (adhesion) to the substrate. The base in general must be strong, not having delaminations and dust-free. All delaminations are cleaned, large cracks are covered with a thick cement mortar (preferably based on Non-Shrink Cement - BUTs). Dust is removed (ideally) with a special “construction” vacuum cleaner, if it is not available, the surface is carefully swept. Additional dedusting is carried out with a primer. Ideal for these purposes is Betokontakt, which gives a rough surface and creates excellent adhesion between the base and the screed. Although "Betokontakt" is quite expensive and it is acceptable to use other soils. Walls and partitions with which the screed will come into contact must be temporarily waterproofed. To do this, a roofing material tape is glued to them, from below, so that its upper edge is 10-15 cm higher than the level of pouring the screed. Some builders recommend that customers install floor waterproofing in all rooms. This is absolutely wrong! Firstly, waterproofing will create a layer between the screed and the base, which will prevent adhesion. This will reduce the strength of the tie. Secondly, in the event of a leak from the neighbors from above, all the water will remain in your apartment, filling the “trough” of the waterproofing. This can be regarded as a touching concern for the neighbors below, but it is unlikely that when you make repairs, you are achieving just that. However, since the pouring of the screed is associated
due to the fact that a fairly large amount of water is on the floor, so as not to disturb the neighbors below, you should carefully examine the base for through holes, cracks and crevices (especially in places where floor slabs and floor slabs meet walls). If any are found, they should be covered with BUTS. In this case, we will call the “beacons” the guides along which the screed plane is aligned. The correctness of their installation directly depends on how even your screed will be. For lighthouses, builders use (usually) metal pipes or profiles. The main requirement for the beacon is that it should provide sufficient rigidity - it does not bend and can be securely fixed in the desired position. Everyone has their own ways of installing beacons: someone puts them on "slides" from a thick solution, someone fastens them to the base with adjustable screws. The main thing here is the possibility of precise height adjustment and rigid fixation. Beacons are installed in parallel
, so that the distance between the beacons allows you to rest on two parallel beacons the ends of the rail-rule, which will be used to level the mortar. Beacons are aligned
with the help of a rack level - both along the length of each beacon, and all beacons among themselves. Now almost none of the builders
does not prepare the mortar manually - portable concrete mixers are quite widespread. The quality of the solution prepared in a concrete mixer is usually higher - because. mechanization of the process allows for better mixing of the composition. To make it easier for you to level the screed
, builders sometimes increase the amount of water in the solution. This cannot be done. the result will be a loss of screed strength. To increase the plasticity of the solution and facilitate its leveling, special additives are used (eg ESCODE-P80), which allow achieving good plasticity with a small amount of water. Strictly speaking, the normal water content in the cement paste (thickness of the mortar) is determined using special (very simple) instruments. In practice, builders do it "by eye" and, with sufficient experience and a conscientious approach, they are not mistaken. By eye, the solution should have the consistency of a thick dough - not be lumpy, crumbly, slightly spread on a flat surface, but not spread. The prepared solution should be used within 1 - 1.5 hours. If part of the solution is not used during the day, then it is impossible to leave it overnight, covering it with a film and adding water (as some builders sometimes do). The pouring of a wet floor screed in each room (or on each plane) must be done at a time. You can't fill half the room today and half tomorrow. This is allowed only in different rooms, or at differences in the level of the screed. In this case, between the screed planes, filled in different time or having different levels, it is better to leave a damper seam 1-2 cm wide. When pouring the screed, it is recommended to often “pierce” the freshly laid, liquid mortar with a thin metal rod. This is done in order to avoid the appearance of air voids in the thickness of the screed. Sometimes, when pouring a mortar, air “lenses” are formed in the thickness of the cement paste, and the severity and viscosity of the mortar prevents them from rising to the surface on their own. The puncture solves this problem. Failure to perform this operation
- the main reason for the marriage allowed by builders when installing a floor screed. Although there is nothing complicated in it. To care for the floor screed, you just need to provide it with sufficient moisture for 7 to 10 days. (SNiP 3.04.01-87 p. 4.8). The fact is that cement gains 90% strength within 24-28 days after the preparation of the solution. For the chemical processes that take place in the solution, water is required - the solution must solidify, and not dry out. The natural drying of the screed leads to the fact that the solution does not have time to harden. The screed is “allowed” to dry only after the required strength has been achieved - otherwise it will definitely crack. To prevent premature drying of the floor screed
, for starters, you need to moderately moisten it with water 2-3 times a day. Two or three days later, after pouring the screed, you need to remove the beacons, treat the recesses remaining from them with soil and wipe them with fresh mortar. Then the screed should be moistened again abundantly and covered with plastic wrap for 2 weeks. If for some reason this is undesirable, then you should continue to evenly wet the screed 2-3 times a day. There is no need to rush here! The result of "acceleration" technological process can be very deplorable - the screed will have to be completely redone. Now about how to evaluate the result.
If you find a marriage, I recommend that you immediately call an expert. Determining the extent of a disaster and how to deal with it requires professional knowledge and experience. Yes, and it is better for a professional to talk with scammers. Of course, the work of an expert is paid for by the perpetrators of the marriage. All further actions must be documented!
Violations of quality standards should be immediately recorded on paper (preferably photographed). If the builders refuse to sign a bilateral act, call the witnesses and act the marriage yourself. At uneven surface floor screed or unacceptable slope - oblige the builders, at their expense, to eliminate the marriage. To do this, it is best to use a leveling compound, which is applied in a thin layer (after all, you do not need to increase the thickness of the screed due to someone else's oversight). Such a composition is quite expensive, but this (agree) is not your problem. The application of the composition requires special attention to the observance of technology and the high qualification of builders. If your builders give you doubts in this regard, hire specialists, and pay for their work at the expense of the builders who allowed the marriage. If there are cracks
- “embroider” cracks, prime and cover them with BUTS. Although with a large number of cracks, the screed will have to be completely removed. Here, much depends on the nature of the cracks - it is better to invite an expert after all. If there are voids in the screed (determined by tapping), remove the exfoliated areas, prime and refill. Although even here it may be necessary to completely remove the screed, it cannot be determined without inspection. From this article, you learned what a wet floor screed is and how to fill it. Every adult, even without special building education understands that in order to put any coating on the floor indoors, you must first level its base, which is why a floor screed is needed. What is a floor screed? This is a construction procedure for forming a flat surface on the floor.. Today there are a huge number of varieties of screeds. When performing repairs of apartments, office and industrial premises often used both wet and dry floor screed. A screed solution, referred to as wet, is used quite often and is prepared from sand, cement and water. Additional fillers may also be used. This is the easiest and most inexpensive way to level floors. The main tasks of a wet screed: According to the specific preparation of the type of floor surface, the implementation of the final layer, wet screeds are divided into four types, which are presented below. It is also possible to make self-levelling floors by applying more liquid mixture, which is able to spread on the floor without physical intervention. But it is not worth using only self-leveling floors without creating a key screed. Preparing the floor for a wet screed involves drafting repair work, which include: Note: The primer must be allowed to dry for five hours! As thermal insulation material expanded clay, polystyrene foam plates are used. But the insulation must be tough enough. Expanded clay has the worst heat-insulating, sound-proofing characteristics, but is more reliable, has a longer service life. When performing a wet screed on the ground, insulation must be carried out necessarily, and on the slabs in some cases (for example, if the basement is located below). When performing a screed 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. If it is planned to lay wiring, install an underfloor heating system, repair and construction work is also carried out at this stage, with the obligatory consideration of all technological specifics. Wet screed is performed in several stages, which are listed below. In order for the wet floor screed to be completely even, a system of lighthouses is used in the process of its implementation, which is formed on the floor from profile rails. For the installation of a beacon rail, it is recommended to use a solution intended for making a screed. The use of beacons is used even in small areas. There must be at least two of them so that the solution can be leveled. The proportion of the standard solution: 1 part - cement, 3 parts - sand. To improve the strength characteristics, it is possible to additionally mix the adhesive mass into the solution, which is used to perform tile work. The finished mixture should not: Concrete is recommended to be ordered in finished condition. It's made much better. Plus, it's so much more profitable. Concrete is commonly used for this type of work in private country cottages, as well as the premises of the first floors of buildings. Thick-layer wet screed concrete mix on the upper floors is used only in some cases. Important! To obtain quality screed, the area of \u200b\u200bthe room must be poured at once, since the cement mortar tends to harden after an hour, after which it will be impossible to correct it. If concrete was used as a liquid screed, then after it hardens, the surface is polished with special grinding equipment (a grinder with a special nozzle can be used). This event will help remove noticeable irregularities, prepare the floor surface for laying any type of flooring.
Wet floor screed installation method
Operation number 1. Determination of the horizontal.
Operation No. 2. Determination of the maximum height of the existing floor and the level of height difference.
Operation No. 3. Calculation of height differences when installing a multi-level wet floor screed.
For laying parquet, a multi-layer coating is created - the so-called. "pie". It consists of: the parquet itself, plywood, glue and mastic.A few words about the quality of the material for the device of a wet floor screed.
Operation number 4. Preparing the surface for pouring a wet floor screed
Operation number 5. Setting up beacons
In those places where the screed will have a level difference, plywood formwork is installed, which will prevent the solution from flowing from one zone to another.Operation number 6. Preparation of the mortar and pouring the floor screed
Operation number 7. Wet floor screed - care
Operation No. 8. Acceptance of work
(4m=4000mm)Conclusion
If you would like to sort things out on your own, here are some suggestions:Wet screed types
Subfloor preparation
If the base is soil, then it is preliminarily cleared of vegetation, then a layer of sand is poured (at least 10 cm). When expanded clay is used for this purpose, sand is also poured over 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 obtained much easier, cheaper, since the minimum amount of solution will be used. If repair work is carried out in the bathroom, toilet, then the laying of water pipes is carried out at the same time.thermal insulation
Waterproofing
As a material for waterproofing, roofing material, a thick film can be used. Strips of material should overlap up to 15 cm, go 10 cm onto the walls facing water pipes, which must be lubricated with sealant above the planned level of pouring the solution. Waterproofing is necessarily carried out in bathrooms, as well as in other rooms that are connected, for example, with a basement.Reinforcement
Installation of additional equipment
Stages of wet screed
Placement of lighthouses
Applied solution
After carrying out full preparation for the implementation of a wet sexual screed, it is necessary to prepare the mixture. As a floor screed mortar, you can use ready-made mixtures specially designed for leveling floor surfaces. Today, on the market of building materials, they are available in a fairly wide range, they may differ from each other in some characteristics. To prepare them for use, you must strictly follow the manufacturer's instructions.Filling the floor
Grinding
