When considering how thick your floor screed should be, there are many factors you need to consider. Do not assume that a more impressive thickness will make the design better. This is the sin of many home masters who do not have the appropriate experience. In practice, it turns out that the final strength of the fill does not in all cases depend on the thickness, because the drying process can go wrong, for example, it will last several months, in which 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.
Optimal thickness
Leveling floors is a pretty important process, it is neglected very rarely. This is especially true for residential areas. An exception may be the laying of the finish coating on the logs. 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, then you will need a 70 mm layer, however, the thickness of the screed in this case should not be more100 mm. If we are talking about an electric heat source, then it can be hidden under concrete, the height of which will be 5 cm or less.
After pouring, the solution cannot be heated by 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 above the water heated floor can be equal to the limit of 7 to 10 cm. As for the electrical system for heating, the thickness can be equal to 3-5 cm.
For reference
The curing time of the largest thickness can reach 140 days. The system must be pre-checked for integrity and performance. This is especially true for water floor pipes. The system starts again closer to the end of the hardening process so that the remaining moisture in the depth of the concrete is completely dried.
Minimum screed height
If you are guided by sanitary norms and rules, then in residential premises it is necessary to fill the solution with a layer of 40 mm and above. This figure is the minimum. But in some cases, the formation of a thinner layer is allowed. This includes low activity in the operation of the premises, with regard to utility rooms and storerooms, because they are visited very rarely.
If the thickness of the floor screed is less than 30 mm, the strength of the material mayfail in unforeseen situations. This applies to falling massive objects. From this it should be concluded that the minimum height is limited to a parameter of 35 mm.
It is important to pay attention to exceptions as well. If there is a goal to improve the heat and sound insulation qualities of the floor on an uneven base, a backfill should be formed for a light screed. A solution is poured on the unevenness of the slab, the thickness of which will be 2 cm. After the material dries, a heater or sound insulation is laid on top, followed by a separating thin 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 decide under what conditions the room will be used. Therefore, to some extent, you will be able to determine the operational load on the surface. For example, public rooms such as hallways, corridors, kitchens and living rooms require a significant layer thickness of 70mm or more or reinforcement with which the seam height can be reduced to 40mm.
If we are talking about a children's room that will combine the playing space, it is important to achieve an impressive coating strength. 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. Answer this questionfollows unambiguously - the height of the layer must 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 floor heating system or want to achieve a high strength base for the finish coat, then you should stop at a thickness ranging from 50 to 60 mm. This will be enough, which is especially important for the reinforcing layer. For calculations, doorways should be a guide. After all, if you raise the floor a lot, taking into account the finish coating, then you can reduce them in height, which will imply the need to install 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:
- variety of overlap;
- ground type;
- purpose of the room.
All these conditions affect not only the final thickness index, but also:
- work cost;
- 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:
- minimum;
- medium;
- maximum.
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 the work. The average thickness reaches 70 mm. In this case, reinforcement or reinforced mesh should be used. 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 you intend to use when arranging the system. For example, a layer of concrete with the addition of crushed stone may have a minimum thickness. For thin screeds, self-levelling floor finishing compounds are the most suitable choice. At the final stage, such a surface is covered with a decorative material. With the help of this technology, it is possible to achieve the formation of an ideally even thin layer, after the materials of which have dried, you can proceed with the installation of a decorative coating.
The thickness of the screed above 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 suffice. Experts believe that for normal operation of the system and good heating of the room, the thickness of the screed above the warm floor can be 4 cm. If the screed is higher, then the thickness will complicate the adjustment of the heat supplied, because a huge part of the energy will be spent on heating the concrete.
Things to consider when arranging a screed with a minimum thickness
Familiarizing yourself with the sanitary norms and rules, you will be able to understand that the smallest thickness of the screed can be equal to 20 mm. However, in this case it is necessary to take into account one feature. 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 a minimum thickness of underfloor screed is provided, then you must meet several conditions, among them:
- leveling the surface with a coupler;
- presence of subfloor;
- lack of fittings and pipes.
If we are talking about a technical room, then the thinnest concrete layer cannot be used, because an increased load will be placed on the surface.
Additionally about the thickness of the screed of the water floor heating system
Water heated floor is a system of heating elements - pipes that 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 a water-heated floor as correctly as possible. This will ensure the normal functioning of the system.
Screed thickness is the key to mechanicalstrength and proper operation of the system, as well as efficient heat transfer and economy. 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. The screed under such conditions heats up much longer, however, it also gives off heat for a long period of time.
Laying a screed with a smaller thickness, you will get a floor that heats up in a short time, however, such a design can overheat and become cracked, heat transfer will go in stripes 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 consider 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 space 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. The thickness of the screed reaches 300 mm only in aircraft hangars. The minimum thickness when laying the underfloor heating system is 65 mm. The thickness of the screed on a warm water field should be equal to the limit from 20 to 50 mm. If the structure is hanging, then a heat and sound insulating layer should be laid between the pipeline and the base, then the thickness of the screed will be 35 mm.
Filling the screed on the underfloor heating system
Once you have determined how thick the floor heating screed should be, you should start work. The base is cleaned, because a dirty floor will not be able to provide the desired degree of adhesion. Pure anddry coating should be walked with a primer mixture in 2 layers. To calculate the volume of the screed, determine the thickness by multiplying by the area of \u200b\u200bthe room. For living and domestic rooms, it is recommended to lay the screed in the range from 65 to 70 mm. 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 may react negatively to unforeseen loads. If you plan to install large items indoors, then you should provide reinforcement of the upper layer with a metal mesh. You can use it pointwise or over the entire area. In order to strengthen the screed, you should use solid additives such as fiber or polypropylene chips. The first allows you to get a mixture called fiber-reinforced concrete.
By choosing an impressive thickness of the underfloor heating screed, you will expect the layer to harden up to 1.5 months. Before starting to lay the top coat, you must wait for the complete dryness of the base. In this case, a self-leveling floor is more convenient, because it is characterized by rapid polymerization.
About the features of laying the screed
If you decide to pour a screed for a water-heated floor, then the technology of work will differ only in the presence of damper joints. If we are talking about a room in 10m2, then the seams will be located along the building envelope. 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 are 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 right thickness of the screed on a warm water field. It is also important to check the performance and hydraulic tightness of the system. It is necessary to ensure the presence of a heat-reflecting layer under the pipeline in order to exclude heat loss. The choice of materials for the screed should be approached as responsibly as possible, this is true in relation to cement, which cakes when stored improperly and for a long time.
Conclusion
Before leveling the floor, you must correctly determine the thickness of the underfloor heating screed. This parameter depends not only on the wishes of the user, but also on the design features of the building, floor properties, floor thickness, facing materials and other factors.
