When thinking about what the thickness of the floor screed should be, you should consider many factors. Do not assume that a more impressive thickness will make the design better. Many home masters who do not have the appropriate experience sin this. In practice, it turns out that the final pouring strength does not always depend on the thickness, because the drying process may go wrong, for example, it will last several months, in this case the screed will not reach the desired characteristics. In order to achieve the desired result, it is necessary to carry out an accurate calculation.
Optimum thickness
Alignment of the sexes is a fairly important process, it is neglected very rarely. This is especially true for living quarters. As an exception, laying the topcoat on the logs may be. The thickness of the floor screed for the heated system will differ from the usual 40-mm fill. If you plan to lay water pipes, you will need a 70 mm layer, however, the thickness of the screed in this case should not be more than 100 mm. If we are talking about an electric source of heat, then it can be hidden under concrete, the height of which will be 5 cm or less.
After pouring, the mortar must not be heated by the method of starting a warm floor, because in this case the strength of the screed will be reduced. The basis for these figures are the requirements for the strength of the fill. Experts recommend being guided by more accurate parameters for the screed. Thus, the thickness of the screed over the warm water floor can be equal to the limit of 7 to 10 cm. As for the electrical system for heating, the thickness can be 3-5 cm.
For reference
The curing time of the largest thickness can reach 140 days. The system must be pre-tested for integrity and performance. This is especially true for water floor pipes. The system starts once again closer to the completion of the hardening process, so that the remaining moisture in the depths of the concrete is completely dried.
Minimum screed height
If you are guided by sanitary norms and rules, then in residential premises, pour the solution with a layer of 40 mm or more. This indicator is minimal. But in some cases, the formation of a thinner layer is allowed. This may include low activity in the operation of the premises, as regards utility rooms and pantries, because they are rarely visited.
If the thickness of the screed is less than 30 mm, then the strength of the material may be insufficient in unforeseen situations. This applies to falls of massive objects. From this it should be concluded that the minimum height is limited by a parameter of 35 mm.
It is important to pay attention to exceptions. If there is a goal to improve the heat and sound insulation qualities of the floor on an uneven base, a bedding should be formed for easy screeding. On the roughness of the plate, a solution is poured, the thickness of which will be 2 cm. After the material has dried, insulation or sound insulation is laid on top, then a thin separation film. At the final stage, a solution of the calculated thickness is poured to ensure normal strength.
Features of determining the thickness of the screed
Before you determine the thickness of the floor screed, you must determine the conditions under which the room will be operated. Therefore, to some extent you can determine the operational load on the surface. For example, public rooms like hallways, corridors, kitchens and living rooms require a significant layer thickness of 70 mm or higher or reinforcement, with which the height of the formation can be reduced to 40 mm.
If we are talking about a children's room, which will combine the playing space, it is important to achieve impressive durability of the coating. The thickness of the screed in this case should be 50 mm. If we take into account the above approximate parameters, the question arises as to what is the maximum thickness of the floor screed for the entire apartment. The answer to this question should be unequivocal - the layer height should be the same everywhere.
In some cases, the height difference between rooms or within the same space is created artificially, but this option cannot be called the simplest. If you are equipping a warm floor system or want to achieve high durability of the base for the finish coating, you should stop at a thickness ranging from 50 to 60 mm. This will be enough, which is especially true for the reinforcing layer. For calculations, the reference should be the doorways. Indeed, if you significantly raise the floor, taking into account the finish, you can reduce them in height, which will imply the need for installation of door leaves of unusual sizes.
Additional information on minimum screed thickness
Some experts believe that there is no optimal thickness of the floor screed in the apartment. This belief is based on the fact that the mentioned parameter will depend on several factors at once, among them:
- type of overlap;
- soil type;
- the purpose of the room.
All these conditions affect not only the final thickness indicator, but also:
- the cost of work;
- type of reinforcing mesh used;
- choice of brand of cement.
Based on the height of the concrete layer, it can be argued that the screed can have the following thicknesses:
The minimum thickness sometimes reaches 20 mm. This type of coating can be equipped without the use of reinforcement, but only if self-leveling mixtures are used for work. The average thickness reaches 70 mm. In this case, use reinforcement or reinforced mesh. The maximum thickness reaches 150 mm. In this case, the screed has the form of a monolithic structure with reinforcement. This option for a private house can act as a floor and foundation, which are combined into a single system.
The thickness will depend on the materials that you intend to use when arranging the system. For example, a layer of concrete with crushed stone may have a minimum thickness. For thin screeds, the most suitable choice is self-leveling mixes for finishing the floor. At the final stage, such a surface is covered with decorative material. Using this technology, it is possible to achieve the formation of a perfectly even, non-thick layer, after drying of materials of which it is possible to proceed with the installation of a decorative coating.
The thickness of the screed over the water heated floor is also determined taking into account the diameter of the pipes. If the diameter does not exceed 25 mm, then a layer of 50-70 mm will be sufficient. Experts believe that for normal operation of the system and good heating of the room, the thickness of the screed over the underfloor heating can be 4 cm. If the screed is higher, the thickness will complicate the adjustment of the supplied heat, because a huge part of the energy will be spent on heating the concrete.
What to consider when arranging screeds with a minimum thickness
Having familiarized yourself with sanitary norms and rules, you can understand that the smallest screed thickness can be equal to 20 mm. However, in this case, one feature must be taken into account. Depending on what material is used, the height of the layer may be different. If the screed is formed on the basis of metal cement, then 2 cm will be enough. If you do not plan to use a reinforcing mesh, then the minimum thickness cannot be less than 4 cm. This is due to the fact that a lower layer height will not be able to provide wear resistance and sufficient coating strength.
If the minimum thickness of the screed is provided, then you must observe several conditions, among them:
- screed surface leveling;
- the presence of a rough floor ;
- lack of fittings and pipes.
If we are talking about a technical room, then the thinnest concrete layer can not be used, because the surface will be subjected to increased load.
Additionally, the thickness of the screed system of a water floor heating system
Water underfloor heating is a system of heating elements - pipes, which are filled with water. They should be located throughout the floor area. Typically, such a system is placed in a cement screed to protect against mechanical stress. It is important at the same time to calculate the thickness of the screed for the water floor heating as correctly as possible. This will ensure the normal functioning of the system.
The thickness of the screed is the key to mechanical strength and proper system performance, as well as effective heat transfer and efficiency. If you equip a thick screed, then it will have a large heat capacity, as a result of which it will be much more difficult to regulate the temperature. Under these conditions, the screed heats up much longer, however, it gives off heat for a long period of time.
By laying a screed with a smaller thickness, you will get a floor that is heated in a short time, however, such a design can overheat and become cracked, the heat transfer will go in strips that are limited by the pitch between the pipes under the floor. When choosing the thickness of the screed for a water heated floor, you should take into account that this parameter determines the degree of protection of the pipeline and ensures uniform distribution of heat over the surface.
The total thickness of the screed for the living room should not be more than 100 mm. If we are talking about pavilions, auto centers and warehouses, then this parameter can be 200 mm or less. Screed thickness reaches 300 mm only in aircraft hangars. The minimum thickness when laying the underfloor heating system is 65 mm. The thickness of the screed in a warm water field should be equal to the limit of 20 to 50 mm. If the structure is suspended, a heat and sound insulation layer should be laid between the pipeline and the base, then the thickness of the screed will be 35 mm.
Pouring screed on the underfloor heating system
Once you have determined how thick the underfloor screed should be, you should start work. The base is cleaned, because a dirty ceiling will not be able to provide the desired degree of adhesion. On a clean and dry coating, you should go through a primer mixture in 2 layers. To calculate the volume of the screed, determine the thickness by multiplying by the area of the room. For residential and domestic rooms, laying screeds in the range from 65 to 70 mm is recommended. The layer above the pipes will be equal to 45 mm, while the thickness of the screed under the warm water floor will be approximately 20 mm. If you use mixtures for self-leveling floors, you can reduce the layer thickness to 45 and 25 mm, respectively. This is due to the fact that such mixtures have a higher density.
Experts do not recommend saving much on thickness, because in this case the floor can negatively react to unexpected loads. If you plan to install large objects in the room, then reinforcement of the top layer with a metal mesh should be provided. It can be used pointwise or over the entire area. In order to strengthen the screed, use solid additives such as fiber or polypropylene shavings. The first allows you to get a mixture called fiber-reinforced concrete.
Having chosen the impressive thickness of the screed underfloor heating, you will expect the layer to solidify up to 1.5 months. Before you start laying the finish coat, you must wait until the base is completely dry. In this case, the bulk floor is more convenient, because it is characterized by fast polymerization.
About the features of screed laying
If you decide to fill the screed for a water floor heating, then the technology of the work will differ only in the presence of damper joints. If we are talking about a room of 10 m 2 , then the seams will be located on the walling. A special cushioning strip must be placed along the bottom of the wall. In the future, this will compensate for the expansion of the material when exposed to temperature.
When the room is more spacious, additional seams will be required. Among the functions of the damper tape is not only compensation, but also thermal insulation from the walls, because the coating has a heat-repellent foil. In order to achieve a positive result, it is not enough to choose the thickness of the screed in a warm water field. It is also important to check the operability and hydraulic density of the system. It is necessary to ensure the presence of a heat-reflecting layer under the pipeline in order to eliminate heat loss. The choice of materials for screed should be approached as responsibly as possible, this is true in relation to cement, which, during improper and prolonged storage, cakes.
Conclusion
Before leveling the floor, you must correctly determine the thickness of the screed underfloor heating. This parameter depends not only on the wishes of the user, but also on the structural features of the building, the properties of the floor, the floor power, facing materials and other factors.