It is impossible to imagine repairs without performing work to ensure the horizontal level of the floor, on the surface of which it is then laid decorative coating... For this, after filling the cracks in the base with a special solution, a screed is made. Covering the entire area of the room to a height of more than 20 mm, it hides irregularities, insulates the floor, absorbs noise and hides engineering networks. A semi-dry screed is popular, having a drying time reduced to 10 hours. The strength of the screed is provided by reinforcement for which mesh and fiberglass are used.
If you are going to align or plan a floor base in an apartment, you should figure out what a semi-dry floor screed is. To ensure the base is horizontal, a dry mix is used for floor screed, prepared with the addition of a small amount of water to the cement-sand mix. The amount of added liquid is regulated by the recipe, which guarantees the strength properties of the screed after hardening.
It is impossible to imagine a repair without performing work to ensure the horizontal level of the floor.
The working composition is a moistened mixture of sand and cement, which retains free-flowing properties. The composition contains special additives, as well as plasticizers.
Depending on the scope of work, the distribution of material is carried out by different methods:
Various methods are used to prevent cracking of the formed surface:
It is not difficult to determine the readiness of a semi-dry composition for use. Squeeze the composition with the palm of your hand and make sure that no liquid is released under pressure. Due to the low concentration of moisture in the semi-dry mixture, the screed is not poured, but poured onto the floor surface. Depending on the need for laying heating communications and other engineering networks the thickness of the leveling layer changes. Height differences in the floor surface also affect the thickness of the screed.
The thickness of the leveling layer varies depending on the need for laying heating communications Consider the features of the application of the technology of semi-dry leveling of the floor base. This method is in demand in a number of cases:
A semi-dry mixture does not create an increased load on the floor surface, which allows it to be used with an insufficiently high load capacity of the base.
A semi-dry screed is known among professional builders as a light screed. Its main characteristics include:
The possibility of accelerated installation of the topcoat is an important characteristic of a semi-dry screed An important characteristic of a semi-dry screed is the possibility of accelerated installation of the topcoat:
The characteristics also include the amount of costs for laying the screed. The price depends on the floor area, the thickness of the layer being formed, the reinforcement method used, the amount of plasticizers introduced, as well as other features of the work. If it is necessary to dismantle the old coating and clean the premises, the cost of the work increases. According to its characteristics, a semi-dry screed compares favorably with other types of screeds, performed dry and wet.
The semi-dry variety of bulk coating includes not only cement-sand screed. Powdered vermiculite or perlite crumb is also used as a light filler introduced into the composition of the screed. It is also carried out with increased thermal insulation properties. To align the screed, use a rule that is moved along metal guides. Then plasterboard sheets, moisture-resistant plywood or chipboards are laid, followed by sealing of the butt sections.
Semi-dry screed compares favorably with other types of screed in its characteristics The method of smoothing height differences in the floor using a semi-dry screed has a number of advantages. The main advantages of the technology:
The method of smoothing height differences in the floor using a semi-dry screed has a number of advantages Hard to find construction technology that has no weaknesses. The semi-dry method of forming the floor base is no exception.
The main disadvantages of the technology:
However, moisture is not the only problem when working with a semi-dry method. The main enemy of this technology is the amateurish approach to the implementation of construction activities. A poorly executed seal promotes shrinkage of the coating during operation, which causes deformation of the finish coat.
The amateurish approach to the implementation of construction activities is the main enemy of this technology. And also the leveling of the floor base in a private house is carried out using a variety of technological methods.
The following options are possible:
The choice of a particular screed method depends on individual characteristics premises and customer requirements.
The choice of a certain method of making the screed depends on the individual characteristics of the room. According to the complete algorithm for performing work, you must adhere to the following steps:
After the completion of the main operations, moisture-resistant plywood, particle boards and other sheet materials are installed, which serve as the basis for laying finishing coating... Let's consider the specifics of the main stages.
To level the floor surface using semi-dry technology, the following materials will be required:
Tools and materials needed to level the floor surface The list of equipment and tools includes:
It is also necessary to prepare additives corresponding to the used recipe.
When laying the screed, the specified thickness of the leveling layer should be ensured:
The specified thickness of the leveling layer must be maintained when laying the screed. If it is necessary to lay underfloor heating heating lines, the thickness of the semi-dry base increases in accordance with the diameter of the pipes through which the coolant circulates. When deciding on the thickness of a semi-dry base, one should take into account the load created by the screed material on the floor surface. With a layer thickness increased to 7 cm, the load per square meter of the base increases to 100 kg.
At the preparatory stage, the following operations must be performed:
After completing the preparatory operations, a deeply penetrating primer should be applied to the substrate to prevent moisture saturation. After surface treatment, marking is performed, as a result of which the horizontal line is bounced along the perimeter of the walls at the level of the fill thickness.
It is important to reliably waterproof the floor and professionally lay the insulation, guided by the given algorithm:
Laying waterproofing and insulation of the base Insulation sheets should be carefully adjusted to prevent heat loss.
The increase in the strength properties of the screed is provided by various methods:
Surface and volumetric reinforcement not only increases the load capacity, but also prevents cracking.
Reinforcement increases the strength properties of the screed Installation of lighthouses requires a responsible approach. The flatness of the surface depends on the quality of the installation of the guides.
The installation technology provides for the execution of work in a certain sequence:
After performing these operations, you should wait for the cement composition to solidify, which ensures the immobility of the guides.
Measures for the installation of beacons require a responsible approach Builders use various solutions for screed:
When preparing a screed mixture on your own, the proportions should be observed:
The volume of a semi-dry mixture is determined by the following factors:
To increase the thermal insulation properties, accelerate hardening and ensure the possibility of using the mixture for heated floors, special ingredients are introduced into the composition.
The proportions should be observed when preparing the screed mixture on your own. The process of laying the composition is simple:
One day after the completion of the installation, expansion joints should be cut.
To ensure the flatness of the screed, perform the following work:
To prevent moisture loss during hardening, cover the screed with polyethylene.
After a set of operational strength, measures are taken to lay various types of decorative coatings:
The topcoat is laid on sheets of moisture-resistant plywood or particle boards.
Compliance with the technology requirements when performing work on the installation of a semi-dry mixture guarantees a long period of use, strength and reliability of the intermediate layer intended for the installation of a finishing coating. The quality of the work is influenced by the correct preparation of the floor surface, the qualified installation of the guides, as well as the careful compaction of the composition.
A semi-dry floor screed is a direct alternative to traditional floor leveling schemes. Minimal water inclusion and fast completion times greatly simplify the overall process of preparing and arranging the leveling layer.
This method is similar in many respects and is enviably popular with people who do not want to mess with a liquid solution.
The technology of work involves arrangement on any base and surface
A semi-dry screed is a complex of works on leveling the floor, involving the use of a semi-dry concrete or cement-sand mortar of various strengths. For reinforcement, standard methods of reinforcing the mixture are used - fiberglass or metal mesh.
Through the use of a limited amount of water, drying concrete mix is much faster. So, the average drying time is 4-5 days, which is 5-6 times faster than the drying of the traditional type.
Application of a semi-dry mix is possible on most types of substrates - hardwood floors, concrete slabs, sand or gravel cushions. That is, the device of a semi-dry floor screed can be performed in any room, with any type of base and its technical condition.
The most rational use of this method in conditions when the term of work is limited, and the operational state of the carrier does not provide for the use of liquid and heavy solutions.
The absence of a large amount of moisture has a positive effect on the total weight of the leveling layer and the drying process. After the moisture has completely evaporated, the screed becomes strong enough and ready for any floor covering.
Due to the low moisture content, the screed has a high density and does not shrink when dry
Among other advantages of the semi-dry method, the following can be distinguished:
Semi-dry floor screed is allowed not to carry out additional insulation of wooden structures, building materials and other things that may be exposed negative impacts moisture. The slightly damp mixture is allowed to move freely over the surface of the leveling layer after 12-16 hours.
For flooring flooring, one should proceed from the characteristics of the material itself. Ceramic tiles can be laid for 2-3 days, linoleum for 7-10 days, and it is better to postpone laminate flooring and do it for 35-40 days.
When using a mechanized method, the speed of work increases significantly
Despite a lot of advantages, the presence of the disadvantages of a semi-dry floor screed has not been canceled. The disadvantages include such points as:
The problem with the distribution of the mixture is solved by introducing special plasticizers into the solution, which make the mixture more pliable and soft. When filling the mixture, the first step is to fill and tamp at the corners and mating points. This will eliminate voids and subsidence in these areas.
Arrangement over a large area is rarely done manually - for this, a construction team is hired with the presence of special equipment. The trowel allows you to perform the screed in a mechanized way, greatly simplifying and speeding up the process of grouting.
The minimum layer thickness of 30 mm is the main disadvantage of this type of screed. To solve this problem, the following solutions are used - an increase in layer thickness by 2-3 cm, a separating waterproofing device and reinforcement with the addition of fiber.
The increase in layer thickness contributes to a significant increase in the strength and performance of the mortar after drying. Laying waterproofing allows you to exclude direct contact and interface of the solution with the supporting elements, thereby removing the emerging stresses that can damage the layer.
Fiber is characterized by low weight and easy handling - the material is simply mixed with dry components or added to water
Reinforcement of a semi-dry screed is not necessarily a measure, but it is possible to significantly improve the physical and technical properties of the mortar, the durability of the coating and the surface as a whole. As in the case of wet screeds, two materials are used for the semi-dry method - fiberglass and reinforcing mesh.
Fiber is a composite material that increases the strength properties of concrete and cement-sand mixtures.
Among the advantages of this material, there are such points as:
Reinforcing mesh is a more traditional and familiar material. It is made of plastic and metal with different cell sizes. It fits at the stage of preparation or pouring of the mixture, provides for pairing with various elements and sections of the supporting structure.
For reinforcing a semi-dry mortar, it is recommended to use fiberglass, since this component will not weigh down the overall floor structure. The use of a reinforcing mesh, in the form of fiberglass or plastic mesh, is not prohibited, but it will still not give such a result.
If mesh reinforcement is more familiar and categorically do not want to apply modern ways, then the technology of laying the mesh will consist of several stages. The first step is filling and leveling 2-3 cm of semi-dry mass. Next, they carefully lay the required amount of mesh, knit adjacent canvases with a wire and fill in the last layer of 2-3 cm.
The technology of semi-dry floor screed provides for a complex of preparatory measures that greatly simplify the process of finishing work and directly affect the quality of their implementation.
Basic steps in finding the highest point on the floor surface
Preparatory work takes place in stages and consists of the following actions:
Dismantling of old finishes, skirting boards and floor cladding is carried out using hand tools and a hammer drill. Large debris is collected in strong bags and taken to a landfill; it is better to use a construction vacuum cleaner to remove fine dust.
Elimination of minor damages is carried out by sealing using construction and cement-sand mixtures. Deep potholes and cracks are embroidered, cleaned, primed and repaired with a similar composition.
To eliminate small surface imperfections, you can use a cement-sand mortar.
Calculations are performed using a simple algorithm. To do this, a horizontal line is drawn on the wall around the perimeter of the room. This can be done using a laser or bubble level. From this line, every 50 cm, measurements are made to the floor surface.
The smallest distance will indicate the highest location on the floor plane at this point. That is, from this point, the thickness of the screed layer should be calculated. To do this, the minimum possible layer thickness of 3 cm is subtracted from the found distance and a second line is drawn.
For the arrangement of waterproofing, roll materials or polyethylene film with a thickness of 100 microns or more can be used. The material is laid over the entire floor area and is admitted to the walls with a margin of 15-20 cm. A special damper tape acts as a heat and sound insulation strip, which is glued to the bottom of the wall to the height of the screed.
Solution preparation is carried out in two ways - manual and mechanical
Mixing can be done mechanically or manually. In the first case, an electric pneumatic blower or mixer is used. This is a special device that allows you to mix, prepare and supply the solution to the work site.
The manual method involves kneading a semi-dry mixture directly on the floor surface. In most cases, it is the second method that is used, since the equipment is quite expensive and is used only when pouring over large areas.
The standard proportions of the mortar are not much different from the classic mixture - 1 part of cement to 3 parts of sand. For 1m3, 500-600 grams of reinforcing fiber is added.
The water must be clean, free of rust particles and technical waste. The maximum allowable number of clay inclusions in the sand should not be more than 3% of the total mass. When using Portland cement, it should be borne in mind that the finished solution will have a smaller brand. Therefore, it is recommended to take Portland cement grade M500.
General scheme for installing and fixing linear guides to the surface
When cooking by hand, it is advisable to enclose the area for mixing the ingredients. Further, in the established place, a hill is poured from three parts of sand and part of cement - the cycle is repeated the required number of times. Next, water is poured into a bucket and the required amount of fiber is mixed. The exact amount depends on the manufacturer and the volume of the mixture.
Water is gradually poured into a hill of cement and sand, mixed well. To determine the consistency of the solution, take a small amount of the mixture in your hand and squeeze it strongly. If water drips, and the mixture crumbles, then add more dry components. The result should be a solution that forms well under pressure and does not release water.
The setting of the guide beacons is carried out after the arrangement of the waterproofing layer. You will need to purchase a beacon or plasterboard profile. The first linear guide is set at a distance of 20-30 cm from the wall. For this, a cement-sand mixture is used, which is pinned under the guide until the upper edge of the profile is equal to the intended floor level.
The distance between the second and subsequent guides is selected based on the tool with which the semi-dry screed will be aligned. Usually, this distance is less than the length of the instrument by 20 cm.
Semi-dry floor screed - do it yourself technology
The technology of the device implies that floor leveling work begins once after a certain amount of mortar has been prepared. The manual method is well suited for realizing where the mixture is fed additional equipment problematic.
The initial setting of the mixture will occur after 50-60 m, which will affect a significant deterioration in its plasticity and complexity of distribution.
A semi-dry do-it-yourself floor screed is performed in the following sequence:
After finishing work, the surface is covered and left for at least 12 hours. If desired, over time, you can dismantle the guides and wipe the formed seams. After 4-5 days, you can start finishing the premises.
As a supplement to the text version, we recommend a video - semi-dry floor screed, technology for arranging concrete base and manual alignment.
The average cost depends on the brand of cement used, additional additives to the mortar, the use of additional equipment, etc.
Below is the average cost of the main Supplies and the rental price of the necessary equipment.
The traditional ties are being replaced by new, more modern technologies which are more efficient and less labor intensive. Semi-dry screed allows for Finishing work much faster. Repair times are reduced, and the quality of the coating is in no way inferior traditional method leveling the floor. According to experts, it is much easier to work with the materials that are used to create such a coating, therefore this method is becoming popular.
To level the floor surface, a semi-dry cement-sand mortar is used, which allows you to create a coating that meets all the requirements for the quality of modern finishing materials.
Semi-dry cement-sand mortar Unlike traditional technology, various components are used to enhance the performance of the coating. For example, fiber is added to the composition to increase flexural and tensile strength. To give elasticity to the finished mixture, plasticizers are added to its composition.
Thus, after the completion of all the work that will be described below, a stable base for finishing is obtained, which meets all the requirements for strength and durability.
There is a semi-dry floor screed, the technology of which involves the use of fiber. And also there is a method of making such a coating with a reinforcing material. These methods use different components that increase the positive qualities of the material. In the version with fiber, there are no special additives, except for itself, and when using a reinforcing mesh, plasticizers and hardeners are added to the composition.
Before leveling the floors, it is necessary to glue the polypropylene tape around the entire perimeter of the walls in the room where the work will be carried out. This will create an expansion joint that neutralizes deformations and prevents sound transmission from the floor to the walls. Polypropylene tape can be glued with liquid nails. How exactly to do this, you can see in the photo below or watch the video.
Stick on polypropylene tape
In this example, we will consider the option of making a subfloor using fiber. You can also find a video with the production of this type of work. Before starting the manufacture of the mixture, it is necessary to prepare the base. If there are fragments of old coverage or global depressions on it, they must be eliminated. The remains of the old coating are removed using a perforator, and the pits are filled with cement-sand mortar. Before starting work, you need to complete the installation of communication elements: electrical wiring, heating pipes or.
The mixture must be made in certain proportions: cement, sand, water in a ratio of 1: 3: 0.3.
The mortar is kneaded in the area where the screed will be located. To do this, mix the cement with sand in appropriate proportions. From these components, a sink is created, into which water with fiber is poured. Then mix gently, avoiding liquid leakage.
Mixing solution If all the ingredients are used in the correct ratio, then you should get a mixture that, when squeezed in a fist, creates a lump and does not crumble.
A clenched fist creates a lump In this case, the liquid should not protrude from this lump. After making sure that the mixture has the correct consistency, you can proceed to the next step.
A semi-dry do-it-yourself floor screed, made using this technology, is evenly distributed over the entire surface of the room. Excess or lack of material in individual areas should be avoided. Next, the mixture is pressed. To do this, use a special tool or simply press the surface with your feet. At this stage, the surface is not even enough, therefore it is necessary to make beacons along which the final alignment will be made.
The laser level is installed in the room where the work is done. The platform is leveled with a grater and the distance from it to the laser beam is fixed with a ruler.
The ruler fixes the distance Two meters from the site, make another one at the same distance from the beam.
Two meters from the site By applying the rule, a line is created between the pads. It will be a lighthouse. It needs to be done from one wall to the opposite.
The gaps between the lighthouses are carefully overwritten with the rule. At the same time, the formation of depressions or bumps is not allowed.
Overwrite If, during work, a pit has formed in any place, then the mixture is added to this area and rubbed again. All bumps and irregularities are cut off by the rule.
This method allows you to create a very flat and strong base under Decoration Materials... We have a lot of videos on our site with all the stages of such work. Having carefully watched the videos, you can apply the information received in practice.
In rooms that have an area of more than 30 m2, it is necessary to arrange expansion joints. It is required to carry out such work to compensate for the linear expansion of materials over large areas.
Arrange expansion joints To do this, using the rule, recesses are made half the size of the screed thickness from one wall to the opposite. The distance from one seam to another must be at least six meters. the expansion joint is filled with grout. With or any other decorative materials that do not require glue, the seams are left empty.
To wipe the surface, use special grinders. On small areas, you can use a float, which removes all defects on the surface. After processing the base with these tools, a very flat and smooth surface is obtained.
Special grinders A semi-dry floor screed with your own hands is the best way to create an excellent base for finishing materials.
After the material has hardened, tiles can be laid on it, linoleum or laminate can be laid. The properties of such a coating allow you to arrange warm floors or raise the level without loading the floor. Semi-dry screed creates a durable coating that does not deteriorate for a long time and does not require maintenance.
In this video, you will learn how to independently make a semi-dry screed step by step.
Thanks to this material you will receive detailed useful information.
Photo source: abvmaster.ru;
www.masterstroy.net
Uneven floors can ruin the look of any interior. It is impossible to lay either parquet or laminate on such a floor. The floor covering will not only not hide the irregularities, but also deteriorate faster. Therefore, the first step in repairing any room should be a floor screed: semi-dry, dry or wet. It all depends on the time frame in which you need to invest, on the effort and costs that you have to decide on.
Semi-dry screed is the leveling of floors by using a rigid, semi-dry cement-sand mortar, the strength of which is provided either by a metal mesh or by adding polypropylene fiber. This type of screed in terms of time is a cross between a wet and dry screed. If, with a dry screed, proceed to further work it is possible immediately, with wet - after 2-4 weeks (up to 28 days), then with semi-dry - after 4 days.
Fiber: 10 sq. square meters of it will need 0.27 kg
At the same time, a semi-dry floor screed has a number of advantages. When using it, inexpensive, but high-quality materials are used. After the cement-sand layer is applied, leveled with a rule and sanded, it no longer requires additional processing: it is not necessary to level or moisten it, as is done when screed with liquid cement-sand mortar. This results in a solid monolithic even base under flooring, which is not afraid of cracking and shrinkage.
When installing a semi-dry screed, you do not need to worry that the liquid will leak out of the solution and flow to the lower floor. Semi-dry screed with fiberglass is not only durable and resistant to mechanical stress, but also has sound and thermal insulation characteristics... Installation of such a screed can be carried out using mechanized means, which greatly facilitates the process.
A semi-dry floor screed is applied to the following base:
Semi-dry floor screed is carried out with sand-cement mortar. To ensure the strength and solidity of the screed, either a metal reinforced mesh, which is covered with a semi-solidified solution, or simply add fiber to the solution. Polypropylene fiber prevents cracking. For a semi-dry floor screed with the addition of fiber, you will need the following materials:
Anti-shrink steel mesh reduces cracking, and in the event of cracks, keeps the material solid. For a semi-dry cement-sand screed based on a mesh, you will need:
For the implementation of a semi-dry screed on a floating basis, which additionally provides thermal insulation, the following materials are also used:
To prepare a solution using fiberglass, 120 liters of sand, 150 g of fiberglass, 50 kg of cement are poured into the pneumatic blower. Fiber consumption for a room of 20 sq. M. - 0.54 kg. Everything is mixed for 3 minutes, after which water is added, the solution is still mixed and fed through a hose to the place where the screed will be carried out.
When using a reinforcing mesh for the preparation of a solution, take 1 part of Portland cement-400 and 3 parts of sifted sand. The mixture can be prepared directly at the place where the screed is laid, even without the use of a concrete mixer. First, sand is poured, then cement. Water is gradually added to the dry mixture. The main thing with her is not to overdo it. The solution must be plastic. If you take it in hand, it will form easily. But the water should not drain from it.
Also, during kneading, an elasticizer is added, which will make the screed even more plastic and resistant to temperature increases (important for laying underfloor heating). The solution is thoroughly mixed and then applied to the base. In addition to the usual mortar, sand concrete and other ready-made dry mixes for floor screed are used, which are diluted with water according to the instructions for use. Hardening accelerators, plasticizing materials, reinforcing fibers and light fillers such as foam crumbs or expanded clay are added to screed solutions. Thorough mixing of the solution is a guarantee of the quality of the future screed. Tools that come in handy for a semi-dry floor screed:
As with any screed, first you need to prepare the base. To do this, remove the remnants of the old floors, sweep away all the debris and examine the remaining surface.
If there are deep pits, sharp protrusions between the plates, then they are covered with either a primer or special glue. It is important that the flaws, if they remain, are substantially smoothed out. The primer also prevents the substrate from absorbing moisture.
The use of edging tape is especially important when installing underfloor heating. After all, the temperature affects the further quality of the floor. The tape is either bought ready-made, or a large roll of expanded polyethylene is cut into tapes. It will provide sound insulation and the safety of the screed.
After preparing the solution (as described above), the first layer is laid. Its thickness is about 20 mm. The first layer of the solution is tamped well, after which it is laid reinforcement mesh... Pieces of mesh are tied together with pieces of wire or welded. On top, 3-4 cm of a semi-dry solution is poured and tamped. If fiber is added to the solution, then additional mesh reinforcement is no longer required.
To achieve perfect flat surface work is underway to level the poured solution. Via laser level determine the differences in the base. An important stage of the work is the installation of beacons. These can be profiles for drywall, which are laid in a solution, and then the surface is leveled according to the rule and the excess material is removed. To install beacons from profiles, the entire surface is drawn with lines.
The distance between them should not exceed the length of the rule with which the floor will be leveled. Heaps of solution are poured along the lines, on which the profile is laid. A rule is set on the profiles by the edge, which is pulled in the direction of the profiles. Excess material is removed, and the grooves are slightly loosened and the solution is re-added. By profiles, using the rule, all unnecessary is removed.
In order to rub the semi-dry solution, use a grater. When the solution hardens somewhat, the profiles are removed, and the traces of them are immediately filled with solution and polished. A grinder is used for this.
After the screed is laid, it must be covered with a film so that it does not dry out too quickly. For the maturation of the cement stone, it is necessary to provide a humidity regime during the day with a screed thickness of 5 cm.After 4 days, decorative flooring can be laid: from linoleum to parquet boards and vinyl tiles. After performing such a screed, any material will fit perfectly on leveled floors.
This method is called "semi-dry floating screed", it is performed using a conventional mortar and metal mesh laid on a layer of heat-insulating materials.
The very first step is to remove all debris from the screed base, including the remnants of the old floor.
When you see the quality of the floor, if you wish, you can fill in some bumps and irregularities with glue. It is important that there are no abrupt transitions, depressions, bulges. The bulges are knocked down or cleaned off, moistened with water, after which a solution or glue is applied. There is no need to rush to apply self-leveling, otherwise all the liquid will drain in one place and the effect will be exactly the opposite. To smooth out irregularities, use: technonikol, bikrost, linocrom.
Around the entire perimeter of the room, a tape of foamed polyethylene is laid (isolon is also suitable). Fasten the edging tape with liquid nails, double-sided tape or silicone. The strips should be slightly wider than the future screed. The excess can be cut off. The resulting edge will become an interlayer between the wall and the screed, providing sound insulation, shock absorption and durability of the structure.
To avoid the ingress of moisture in the bathrooms or premises of the first floor, all seams are hermetically glued, and then fusion is performed using roll material. The rolls are preheated, fused onto the base and the lower edges of the walls, the strips are glued together. A cheaper option is to use bitumen impregnated roofing material.
The next stage is the installation of the thermal insulation layer. Before that, you need to use a laser level to measure the entire area and determine the irregularities, make the appropriate marks on the walls. In places with deep recesses, you will need to lay an additional layer of expanded polystyrene. To adjust the thickness of the polystyrene to the required one, use a thermal cutter. She cut out the required thickness of the foam layers.
Beacons are screwed onto the leveled floor surface. In this case, screws for wood. They are easy to screw in and adjust the height. This method is suitable specifically for polystyrene, since it is light and loose on the floor, and with any movement it gets lost. When laying a layer of expanded polystyrene, you will need to make holes in the sheets so that they fit well in those places where the beacons are installed. Sheets must be stacked very tightly, without unnecessary gaps. If there is a need to lay communications or wiring, then it is easy to cut the necessary holes in the foam for this - grooves. When laying the pipes, they are wrapped in isolon, and the wires are placed in a corrugation made of stainless steel or plastic. When laying EPS boards, leave a path between them unpatched. This is done so that you do not have to stomp on fragile foam plates.
The mortar is kneaded either in a tank using a construction mixer or on the floor. The finished semi-dry mixture is scattered with a shovel in a layer of 2 cm over the entire surface of the room. Next, the mesh is laid. If it consists of several pieces, then they are fixed to each other with a wire. A new layer of solution is poured and leveled from above. It must be trampled down carefully. Next - alignment using the rule and level. If irregularities have formed, then the solution is poured in those places. In order for it to better adhere to the previous layer, the lower layer is slightly loosened.
The penultimate stage will be grouting and sanding. Thanks to this, ideally smooth surfaces are achieved. When the screed hardens, knock down the bumps with a metal spatula, and level the places of their formation. To do this, moisten the solidified surface from a spray bottle, spread a solution of sand and cement (1: 1) on top, rub it with a wooden or polyurethane float. After leveling, the surface is checked again using a rule and a level. Next, the beacons are removed, and the places where they were installed are additionally overwritten. Grind the surface with a grinder.
Semi-dry screed has strength and durability due to the use of reinforcing mesh or fiber additives. In order to at the same time insulate the floor, they use the technology of "floating screed" with the laying of a heat-insulating layer. Ensuring the strength of the structure, tight deadlines for floor readiness for further operation, a variety of methods and means - this is what distinguishes a semi-dry screed from other types. The video will help to fully present and understand the technology of the process.
As a proven and reliable contractor for the installation of semi-dry floor screeds, we recommend the company "Eurostroy 21 Century" (website of the company), which has been in the construction services market for over 10 years and knows absolutely everything about this method of floor leveling! On the site you will find detailed description technologies of work, a lot of useful articles, interesting videos, as well as more than 1000 photos from various objects. And if you wish, of course, place an order for a free departure of the measurer to your facility.
Beginning renovation work Each owner understands the importance of selecting high quality materials. But I want practical products to be distinguished not only by their durability, but also by their convenience and ease of use. Consider what a semi-dry floor screed is, where the technology came from and what are its features, differences from traditional options.
Area leveling technology first appeared in Germany in the last century. Proving to be extremely convenient, the semi-dry floor screed quickly gained popularity, first in Europe, and then came to us. The main difference from the traditional wet screed is in less water, as well as the addition of polypropylene fiber. Semi-dry leveling differs from dry leveling by "moisture", that is, by the addition of liquid.
The use of technology is justified in the following cases:
Do-it-yourself work is possible, in rooms on any floor, where heavy materials cannot be used and a dry floor screed will not be enough, for example, due to the limited height of the walls. In addition, the floor surface turns out to be perfectly flat, which does not require leveling with leveling masses, which are much more expensive than a semi-dry composition.
Important! The price of the mixture is one third lower than the wet one, besides, the composition practically does not shrink.
Any method of leveling surfaces has its own advantages and disadvantages. Analyzing the pros and cons of a semi-dry floor screed in comparison with a wet cement screed, we note the following advantages:
Comparing the semi-dry technique with the dry Knauf, professionals speak in favor of the first, the reasons are as follows:
Users note the durability of floors with a screed with plasticizers, as well as non-susceptibility to damage at high through loads. Evaluating the advantages of the technology, the speed of work, the minimum drying process, and the absence of the need for further leveling are noted.
But there are also disadvantages:
Advice! To form straight and even corners, it is recommended to tamp the composition. The process does not take much time, but it eliminates the disadvantages of the technology.
It should be remembered that the minimum amount of water provokes a quick drying of the mixture. The most common mistake made by masters is choosing the wrong thickness of the composition overlay, it has time to dry before it grasps with the base. In turn, a layer that is too thick has a high mass, which negatively affects insufficiently strong floor slabs.
The technology of a semi-dry floor screed differs from the usual procedure in its versatility. It can be laid out on concrete slabs, the floating screed is laid out on polyethylene, on membrane material and thermal insulation. To ensure high practical qualities, it is recommended to separate the composition from the subfloor with a waterproofing material along the entire perimeter of the floor, and to separate it from the wall panels with expanded polystyrene tape - this will serve as a good sound insulation.
Important! Such a “floating structure, which is not attached either to the base or to the walls, is not subject to the stresses that arise when adhering to the walls and can break the base.
The following list of devices will be useful to the wizard:
Useful water, dry mix packaged, personal protective equipment and "soles" - these are special pads for shoes with a wide flat platform. They are put on to prevent the finished level from being pushed through when grinding and leveling it. Such "soles" can be made independently from any plane (wood, plastic), equipped with straps.
The correct device of a semi-dry screed requires preliminary preparation.
The stages of work are as follows:
Advice! Expanded polystyrene tapes can also be laid under the screed. The material will serve for additional sound and heat insulation.
Advice! The width of the layout of the mixture is from 3 cm, this must be remembered when placing beacons - as a result, they must be recessed into the screed.
You need to start laying the mixture from the far edge of the room. Distribute the solution in portions, laying out layers of insulation at the corners and joints. As soon as the perimeter is laid, the paths between the beacons are filled. The work phase is best done with an assistant who will ensure a continuous supply of material.
The mixture is laid at the level of the beacons, compacted and leveled using the rule. It is imperative to check the uniformity of the layer, without voids, cavities. The lighthouses must be recessed - they do not pop out, remaining in the mixture forever.
Advice! If you don't want to leave the beacons, they are taken out as quickly as possible so that the mixture fills the void. In this case, the beacons should be made of very thin rods - this makes it easier to minimize the risk of cavities.
The composition can be laid out in layers, especially when reinforcing, but simultaneous laying of the mixture is also allowed. But what and how to reinforce? Consider the materials and the advantages of their use:
Important! The steel mesh prevents only the propagation of cracks, but does not exclude the possibility of their occurrence.
Reinforcement with a mesh is done as follows: the composition is laid out on a pre-laid mesh, then leveled. But a semi-dry screed with fiberglass can either be laid on a synthetic material or have fiber elements directly in the mixture itself.
Reinforcement has its advantages - so the screed does not sag, does not crack, and when using synthetics, it does not lose its qualities during the entire service life. A semi-dry screed made according to German technology can crack only with poor preparation of the base, violation of the technology for preparing the mixture.
Due to the minimum amount of liquid, the composition dries 2-3 times faster than a standard cement-sand screed. Laying is carried out on a prepared and dried base so that during the ripening period the mixture experiences minimal stress. For these reasons, the layout is carried out precisely in strips, taking into account the expansion gaps.
The approximate calculation of the time required for drying is 10-14 days and depends on the following factors:
Partial hardening of the surface is observed after 12 hours, but subject to a certain microclimate.
Optimal conditions:
Partial drying allows you to move around the surface, but you cannot yet cover the floor with a finishing cladding. To more accurately determine the drying time, you should pay attention to the following components in the mixture:
The screed with the listed components dries no more than 7 days, the main drying parameters are indicated on the package.
Since the mass does not contain free water, it hardens quickly, it is also important to take into account the fact that when laying the film, the composition does not adhere to the base. Therefore the minimum layer thickness is 40 mm. If it is necessary to arrange a thick layer, it is recommended to pour a layer of dry expanded clay - this minimizes the risks of uneven distribution of the load on the base.
Thickness options for laying on different substrates:
Advice! When laying under an electric underfloor heating, the semi-dry mixture is laid out in accordance with the instructions written from the floor manufacturer. It is recommended to use plasticizers to ensure the elasticity of the composition.
It is not necessary to spend money on the purchase of the composition if the house has the right brand of concrete, or better Portland cement 400 D20. Also, clean river or quarry sand with a strength modulus of not more than 2.5 is useful. The main thing is that there are no remnants of peat, plants in the sand mixture, clayey fine inclusions are allowed up to 3%.
Fiber is added at the rate of 0.5 kg per 1 m3. So the screed will be denser, the mixture ultimately looks like thick sour cream. Water is added by eye, the exact proportion has not been established. It is necessary to try on a small volume, adding water in portions - if the mixture compressed in a fist does not emit water droplets, the lump does not lose its shape - it's done. When laying out cement base with a spatula, there will be no residue on the tool, the base is smooth.
Advice! If there is an excess of water, you can add a dry composition. Fiber is first mixed with water, and only then all other ingredients are mixed.
A simpler formula for the ratios:
The solution is mixed for at least 5 minutes. Many craftsmen allow the addition of fiber to the ready-made composition, and in the size of 900 g / 1m3. In this case, the progression must be especially careful.
So that there are no questions left on how to make a foundation, watch the video from professionals:
