SELF-LEVELING MIXTURES
Self-leveling compounds are also called self-levelling compounds, floor levelers and self-leveling floors. This is a fairly simple way to level the floor, while getting an excellent result. Suitable if the height difference is not more than 3 cm. Such mixtures can be used to level the floors for finishing with tiles, cork, linoleum, carpet, etc.
The basis of the self-leveling mixture is cement, but in addition to it, the composition also includes special modifying additives that can increase the plasticity and fluidity of the solution. Some additives make it possible to reinforce the solution and in the future to restrain the appearance of microcracks. Depending on the composition, self-leveling compounds are divided into:
- high-strength;
- for warm floors;
- fast hardening;
- thin-layer.
In addition, there are self-leveling mixtures on sale, designed not only for rough finishing, but also for finishing, as well as compositions with special properties. There are also compounds for rough leveling, they are designed for surfaces with significant irregularities.
All self-leveling compounds boast a number of advantages:
- simplicity and high speed of work with them;
- freezing speed;
- high strength indicators, so this leveling method is quite applicable for rooms with a high degree of traffic;
- resistance to temperature changes.
There are few disadvantages to this method of leveling the floor - these are, rather, its features. Large differences in the level of the floor surface cannot be leveled with a self-leveling floor. You need to work with mixtures very quickly - if you hesitate and allow drying, then a flat surface is unlikely to be achieved.
Creating a concrete base
Pouring a reinforced concrete base is required to create a durable high-quality floor (for more details: "How to make a concrete floor in a private house with your own hands - instructions"). It is best to mark the surface for pouring with rails 5 cm wide and 2 meters long. It is worth adhering to a step between them of about 1 meter, which will allow you to fill the solution with stripes. A square meter of reinforced mesh 3 centimeters thick is laid in the center of the room. Along the perimeter of the room, the joint of the base with the walls is glued with a damper tape.
This is done in such a way that it protrudes a couple of centimeters above the level of the future concrete screed. It is best to use concrete mix grade M100. The fill starts from the far corner of the room opposite to where the entrance opening is located. The strips are poured sequentially, and after the mixture dries, the slats used for marking are removed and the seams are filled with mortar. The screed is covered with polyethylene and regularly moistened for better fixing and achieving maximum conditions.
Application process
The thickness of the screed and the materials used depend on the technical parameters of the building, so it is necessary to know the maximum possible load on the foundation and foundation. Cement-sand mixtures are used for the mortar, usually grade 150 cement is used for such work. Such a mortar is laid on the base using a vibrating screed.
Floor device with semi-dry screed.
Before you start laying out the solution, you need to check the base, and, depending on the results, determine the required solution. The thickness of a mechanized semi-dry floor screed depends on the specific tasks of the coating. If you want to lay a coating with the same height in each of the rooms of the house, then the thickness of the screed must be calculated separately for each room, taking into account the thickness of the finish layer.
In general, preparing the surface is one of the most difficult tasks in the screed process. If there are gaps and gaps between the plates, they are covered with a solution, the surface itself is cleaned of debris and dust, treated with a degreasing solution and a primer is applied.
Also, an important part of the preparation will be the calculation of the zero level of the screed, which will subsequently indicate the maximum level of pouring the solution. Previously, a water level was used to calculate the zero level, now laser, more accurate levels are in use
After preparation, pouring and distribution of the mixture will follow. The best option would be to fill the whole room in one day, so as not to create seams between the sections. However, if breaks cannot be avoided, then the seam will certainly be left in order to avoid cracks.
Laying with the help of a vibrorail.
With the help of vibrating slats, the mixture is compacted, and most accurately it is leveled with a leveling squeegee. All work with a semi-dry screed must be carried out without interruption, otherwise possible errors and temporary inconsistencies may cause deterioration of the final screed.
If the semi-dry floor screed is created exclusively by mechanization, then the solution is prepared at the construction site using special equipment. The finished mixture is transported to the site to be poured at a distance of up to 160 meters, and if an apartment on the upper floors is poured, the distance is reduced to 100 meters.
How long does a gypsum-based floor screed dry?
So, the first thing that determines the hardening time of the screed is the basis of the solution. Screeds (or levelers) for the floor are made either on a gypsum basis or on cement.
Gypsum screeds set in about 3-4 hours, and complete drying occurs in a week. It is after 7 days that you can lay carpet, linoleum, laminate or parquet, pour the self-leveling floor. But the tiles on the gypsum screed can be laid after 3-4 days. However, these calculations are only valid for screeds up to 40 mm thick. Further, the thicker the layer, the longer the screed dries.
That is, if for a screed up to 40 mm the formula applies
10 mm = 42 hours (1 day and 18 hours),
then for screeds thicker than 40 mm, for every additional 10 mm, add about 90 hours (3 days and 18 hours). To dry the screed with a thickness of 80 mm, it will take not two weeks, but three. With an increase in the thickness of the layer, the process of curing and drying slows down significantly.
Preparatory stage for soil
So, the device of the subfloor on the ground begins directly with the processing of a piece of land
It is important to know the depth of groundwater in order to eliminate the risk of flooding the foundation. To do this, you can prudently install a drainage system that will perform the function of draining water.
Once the groundwater problem has been resolved, the foundation process can begin. Coarse-grained river sand and gravel with a fraction diameter of about 3 centimeters is used for this. The depth of the layer of these materials should be about 30 centimeters. As soon as it falls asleep, tamping is carried out using a large amount of water. It is unacceptable to use black soil or peat instead of sand, as they are subject to leaching. In this way, they often make a warm floor in the garage, which has proven itself well.
Features of waterproofing under self-leveling floors
Basic principles of waterproofing works:
- Regardless of the chosen type of waterproofing, its layer must be continuous, thus eliminating the risk of water penetration under the floor structure.
- At the junctions with walls and other vertical surfaces, the waterproofing layer should extend vertically upwards by at least 10-15 cm.
- If the base is of high quality, then waterproofing can be carried out using an insulating tape, which closes the joints of the plates and from above it is covered with a layer of mortar.
- To prevent the finished mixture from leaking at the junction with the walls, a special sealed tape is laid around the perimeter of the entire room, which is fixed to the wall with a construction stapler.
Installation
Each type of underfloor heating under a concrete-based laminate has corresponding installation features, we will briefly consider each.
The first type is the water floor.In a simplified form, it looks like flexible pipes laid through a certain system, through which warm water moves, from above this installation is poured with a concrete screed. This type involves the installation of several layers, here they are in the sequence of their arrangement:
Waterproofing is laid on the existing concrete base. At the same time, it is necessary to lay the damper tape around the perimeter.
Next, a heat-insulating layer is mounted, it is most convenient to use foam, the thicker it is, the better the effect can be achieved
But here it is important to control the level of raising the floor so that it does not exceed the rest in the house.
Metal-plastic pipes are mounted on the insulation, it is important that they withstand high temperatures. They need to be fixed using special fasteners-dowels.
Do not forget to make a pipe outlet for connecting to the heat exchanger.
Pipe layout
From above, the pipes are poured with a screed, and a laminate is already mounted on it in accordance with the rules for carrying out such work.
The total thickness of the underfloor heating under the laminate on the concrete floor varies from 5 to 15 cm.
Reinforcing mesh on the pipes of a warm water floor
The electric underfloor heating in its composition has an electric cable, which actually performs the function of heating. Here the energy of electricity is converted into heat. In living rooms, it is advisable to use a two-core cable, it produces less radiation. Although there are options for arranging this type with a single-core wire. For such underfloor heating, a self-regulating cable is mainly used, which is also used to heat water pipes. This type of cable will not allow overheating at one point, because thanks to the matrix, which is located along its entire length, it determines where to add thermal energy and where to take it away.
Heated floor mats
The installation diagram looks like this:
- Cleaning the floor from dirt, if necessary, laying thermal insulation, but it is not mandatory. Regarding the pouring of the screed, it is done as needed, its thickness is not more than 30 mm. Here it is necessary to use a reinforcing mesh.
- Such a floor, before laying the cable, must stand for at least 2 days.
- Cables must be laid in accordance with the manufacturer's instructions.
- Before fixing the sensor and thermostat, you need to make sure that the system is functioning, that everything is working. Next, you can make a screed from above, its thickness is 3-10 cm.
- It is possible to mount a laminate in a month after completion of work.
Manufacturers offer a slightly simplified version - special mats are produced for this, the cable is already fixed to them, you just need to lay them and make a screed on top.
Well, the last type is an infrared warm floor - the most optimal solution for a laminate today.
Laying infrared film
Its installation includes only 3 steps:
- Thermal reflective material.
- Laying infrared film.
- Polyethylene coating.
Fiber tie
As in the previous method, water must be added to the solution in such an amount that it is enough to impregnate and saturate the cement. It is the low water requirement that gives the semi-dry type of screed special advantages, among which there is a high strength of the final coating and minimal shrinkage of the layer, which minimizes cracking.
Fiberglass.
For a fiber screed, fine sifted sea sand with a grain diameter of 0.01 to 0.05 mm is required, Portland cement M500, produced in accordance with GOST, a plasticizer used to increase the strength, mobility and elasticity of solutions, and fiber with reinforcing properties, which increases the strength of the solution and does not gives rise to cracks.
Fiber screed process
We pour sand into the mixer in the amount of 120 liters, to which 120-150 grams of sand and 50 kg are added.cement. Next, 15 liters of water are poured and a certain amount of plasticizer in the amount of 1.5 liters per cubic meter of solution.
After the screed is laid, it is polished with a special machine, which gives a greater evenness and density of the layer. Sometimes during ironing, microcracks can form that do not affect the characteristics of the floor.
After the floor has been ironed, it is protected from external factors that can adversely affect the final quality of the screed.
How to care for a semi-dry fiber screed?
If a room with a freshly made mechanized floor screed has drafts, then its surface is covered with polyethylene for a day, which gives the cement protection from moisture changes. Instead of polyethylene, you can constantly moisten the screed with water. Already after 12 hours the screed is suitable for walking, but after 94 hours you can put the finishing layer.
Fibre-reinforced fiber provides many advantages over traditional reinforcing meshes for such work. The addition of propylene fibers to the solutions minimizes the appearance of cracks, while the steel mesh is used after they appear. Thanks to the fiber, a mechanized semi-dry floor screed lasts longer and retains its appearance.
A solution for a mechanized screed is made immediately before the start of work, at the construction site. For mixing, a pneumatic blower is used, which combines the functions of a mixer and a concrete pump. The components are loaded into the reservoir of the pneumoheater, mixed and fed, under the influence of compressed air, to the installation site.
The feed is carried out through dense rubber hoses (diameter 50-65 mm). The power of the pump allows you to transport the mixture horizontally to a distance of up to 180 m, and vertically - up to 100 m (to a height of 30 floors). The pneumatic blower is installed on the street near the house (under the windows or at the entrance to the entrance), sand, cement, fiber and other additives (if necessary), water are stored nearby. The components are mixed outdoors, and there is no need to bring them into the house or lift them to the desired floor - the finished mixture is fed to the place of work through hoses. Thus, the room in which the screed is laid will remain relatively clean - without construction dust and lumps of mortar on the walls.
What can replace the damper tape
In fact, the damper tape is polyethylene foam, cut into strips 15 cm wide.
It follows from this that in the absence of a special tape, we can replace it with ordinary rolled polyethylene foam (izolon, penofol, foilizol) cut into strips of 10-12 cm (depending on the thickness of the screed).
Moreover, it will be cheaper at times compared to buying a special damper tape.
So, let's say we need 50 meters of this same tape.
To do this, we take 5 linear meters of rolled PPE (1 m wide) and dissolve it into strips of 10 cm using a conventional construction knife. Thus, we get the same 50m. damper tape.
Mounting process
When the concrete floor has been introduced into the pie on the ground, the process of laying the heating circuit can begin.
There are a number of rules:
- in order to prevent excessive heating of the coating, it is necessary to carry out a competent placement of pipes over the entire area of \u200b\u200bthe room. A denser installation is carried out along the perimeter, and in the center the contour should be less frequent, and the indentation from the walls of the room should be at least 15 centimeters;
- regardless of which laying scheme is chosen, it is necessary to observe the interval between adjacent pipes from 0.3 meters;
- if the pipe is located at the junction of the slab and the ceiling, it should be separated with a special metal sleeve;
- the length of the heating circuit should not be allowed to exceed 100 meters, since in such a system the main parameters of the coolant circulation will decrease (read: “How to make a warm floor with your own hands in a private house”).
Laying is done in two main ways:
- bifilar - in a spiral. In this case, uniform heating of the pipes is characteristic due to the alternation of supply and return sections. A low-power pump is used to supply liquid, and laying pipes is very simple due to the observance of an angle of 90 degrees between adjacent sections;
- meander - zigzag. The coolant in such a system cools down during its passage along the contour, and the surface warms up unevenly. Pipes can turn along the course in absolutely the opposite direction, which affects the complexity of installation. This method is more suitable for rooms with a linear slope, since the coolant will circulate faster and will not have time to cool. A cabinet with equipment is installed at the top point of the circuit. Also, this method of laying allows you to heat the most spacious rooms.
Concrete screed and its functions
The screed, when constructing floor heating structures, simultaneously performs a protective, leveling and heat transfer function.
At the same time, the laying of a warm floor in a screed is carried out only if water pipes or electric wires are used as a heating element.
Infrared film floors should never be poured with concrete.
Protective function
Concrete layer protects underfloor heating from damage
Filling the heating elements with a layer of concrete makes it possible to protect them from external physical influences. Without a screed, electric or water floors can be crushed by the weight of the furniture placed on the floor covering or be subjected to regular impact when people move around the room.
All this can lead to a violation of the flow of the coolant through the pipe or to damage to the insulating braid of the heating cables. Concrete in this case allows you to avoid such troubles and significantly extend the life of the entire heating structure.
Leveling function
If the base is uneven, then it is worth leveling it with a concrete screed
In the event that the draft base has some defects in the form of horizontal slopes, bumps, depressions or cracks between the floor slabs.
If the rough concrete base is relatively even, then the step of installing the underlying concrete screed can be skipped.
If the subfloor has too obvious defects, then it will be simply necessary to lay a water or electric underfloor heating in the screed.
Heat transfer function
For any heating system, an important indicator is its coefficient of performance (COP). Properly poured concrete screed makes it possible to maximize this figure.
The thing is that concrete has excellent thermal conductivity, which cannot be said about air and many floor coverings (linoleum, laminate, etc.). Therefore, a thin layer of concrete mortar laid on top of the heating structures contributes to a faster transfer of thermal energy.
In addition, the heated concrete mass can transfer heat to the room for a long time, which helps to maintain a comfortable temperature.
To maintain high heat transfer properties, it is not recommended to cover the concrete floor of underfloor heating with materials that have insulation properties - carpets, warm linoleum, etc.
The best option to maintain high efficiency is tile or porcelain tiles.
Thermal insulation layer
You can get a base that is protected from freezing and heat loss by creating a high-quality heat-insulating layer. Yes, and the underfloor heating system will be additionally protected from external influences of low temperatures. The functional essence that the design of a warm floor on the ground has is that the heat-insulating layer blocks the leakage of heat (about 20%) and directs it straight up into the heated room.
A high-quality thermal insulation layer has a number of features:
- low thermal conductivity;
- high strength;
- preservation of the main characteristics at high humidity, etc.
To date, you can choose many types of materials for laying thermal insulation.
Particular attention should be paid to expanded polystyrene
There are several options for using this material:
- pure polystyrene foam needs to be coated with polyethylene on both sides;
- expanded polystyrene coated with aluminum foil - the easiest way to fit and does not need additional fasteners;
- extruded material does not need additional coating.
LEVELING WITH GYPSUM FIBER SHEETS GVL
Leveling with GVL is called a dry screed. This process is much simpler and faster, but the quality of the finished screed is inferior to the monolithic one. A layer of expanded clay is laid under the GVL, which plays the role of a heat insulator. The technology allows the use of other materials that have similar thermal insulation properties.
GVL leveling begins with cleaning the surface of dust and dirt, after which a waterproofing material is spread on it, which can be a plastic film. Its strips are laid with an overlap of about 10-15 cm on top of each other and with a 10 cm approach to the walls. It is better to use an edge tape around the perimeter of the room, which is located between the plastic film and the expanded clay layer.
Expanded clay must be carefully compacted and leveled to the intended level. The first plate is mounted in the corner closest to the door, fastened with self-tapping screws. When the first layer of GVL is ready, proceed to the installation of the second, which is attached to the glue. Be sure to shift the sheets by 25-30 cm relative to the first layer. For reliability, the second layer can be attached with screws to the first. Some experts recommend installing beacons in the form of wooden bars or metal U-shaped profiles. For movement on expanded clay, sheets of plywood or GVL are used.
At the final stage, the joints of the plates and the attachment points with self-tapping screws are primed, then the rest of the surface is also primed, the excess plastic film and edge tape are cut off. An important advantage of this method of floor leveling is the ability to perform it in stages, in several approaches, and not in one day, and this greatly facilitates the process when floor leveling is done by hand.
Dismantle or restore
Dismantling you can easily do it yourself. You should not start repairs if you do not have the necessary skills as a builder, you do not understand anything in this matter. In this case, you need to seek help from craftsmen from construction organizations. All kinds of newspapers and magazines are just full of offers of construction and dismantling services.
Over time, any floor covering becomes unusable. Concrete may begin to paint, flake and crack. In such a situation, it is worth deciding whether to dismantle the old screed or it will still serve. Basically, the masters advise to dismantle the screed. Such work is cheaper than restoration.
There are points to take into account:
- Is there a need to make the floor lower.
- Poor floor appearance. It may be more beneficial to simply reinstall it.
- Low quality cement.
- Do I need to repair communications or pipes that are located under the floor covering. You may need to install new ones.
- Will the floors of the rooms on the lower floor withstand the additional weight of the upper floor.
- Working with a jackhammer can be dangerous.
Houses that were built in the middle of the 20th century had a wooden or mixed floor: wooden beams were laid on top of metal ones, and there were areas with reinforced concrete elements in the toilet and bathroom.The process of dismantling the concrete floor has its own characteristic features. If you have removed the old cement screed, and now you want to start the process of pouring a new one, then you will not be allowed to implement this project, since the total weight of the cement solution will be large, and the load on the floor will largely exceed the permissible norm. The right choice would be to install the screed on uneven places from lighter building materials.
Proper deletion rules
When starting to overhaul the floor surface, you will have to dismantle the floor screed, the price of which from construction companies is quite high. But we ourselves are able to remove skirting boards, remove linoleum, dismantle laminate, remove parquet or carpet.
Most often, the dismantling of the floor screed is carried out by the impact method using power tools: perforators, jackhammers, diamond cutting wheels. At home, you can use ordinary crowbar, a sledgehammer, a hammer, a chisel, if the thickness of the coating allows.
Dismantling the floor with the use of electrical devices significantly increases productivity. But such a dismantling of the floor screed will also have an increased price. Specialists using the impact method using powerful pneumatic concrete hammers, perforators, and diamond cutting equipment will quickly, but not cheaply, dismantle the floor screed. And in the case of a heavily metal-reinforced coating, the work is carried out using a special joint cutter.
The dismantling of a cement (concrete) screed in any way is carried out by breaking the base into pieces. For the removal and removal of cement-concrete residues, stock up on bags of durable material in advance.
You need to be prepared not only for a huge amount of construction debris, dust, dirt, but also for increased noise generation, which is better to immediately discuss this with your neighbors. It is better to talk and agree on a schedule of noisy work in advance than to receive "guests" from various authorities later, invited by angry residents of nearby apartments.
Dismantling the floor screed will test the strength of not only the neighbor, but also your patience. All repairmen who have passed this difficult test will no longer be afraid of anything! Good luck with the screed!
