How To Choose A Thickness For Pouring A Solution Under A Warm Floor Of A Water Type

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

• Purpose
• Difference from conventional screed
• Number of screeds for underfloor heating
• Underfloor heating components
• Fill composition
• Minimum parameters
• Screed pouring limits
• Recommendations from experts

A warm floor cannot do without a high-quality poured concrete screed, which performs a large number of functions during operation. But for this, you should familiarize yourself with the general structure of a warm water floor, as well as find out what the minimum screed thickness above the warm floor should be in order for it to meet all the requirements and technology.

Purpose

The thickness of the underfloor heating screed will affect the performance of the entire system, as well as its ability to work effectively under conditions of external loads. At the same time, it should be understood that the layer must be optimal and comply with the recommendations of the manufacturers if a ready-made dry construction mixture is used.

If a very thin concrete pour is arranged on the base of the floor, then it will not be able to serve for a long time. In addition, there will be a very rapid heating of the surface and a quick cooling process. She will not be able to bring any benefit. Taking this into account, especially if the room constantly has loads not only from movement, but also from the furniture located, then the minimum screed under the warm floor will very quickly crack and lose its appearance. This will also lead to damage to the floor covering, which will be laid on top.

A thick layer of pouring concrete mortar will also not be able to show all the qualities of a warm water floor system. Heating up such a structure will be very difficult and problematic. There is a high probability of general failure of the pipeline in certain sections.

All this will cause large financial investments in heating costs. After all, it will take a lot of energy for the heat to pass through the thick layer of the screed, to warm the base of the floor in the room.

It cannot be said that there are universal indicators for the construction of a concrete screed over a floor heating system. The fact is that here it is worth taking into account some factors, such as the type of base, the configuration and area of the room where the work is carried out, as well as its purpose. After all, the load in residential premises will be much less than in industrial ones. Therefore, in the latter case, the fill layer should be slightly larger.

Difference from conventional screed

A conventional screed is somewhat different from a screed for a warm water floor. The fact is that in its last form, expansion joints must be arranged without fail. Even in rooms with a small area of up to 10 m ^2, they must be present. In addition, an amortization strip should be arranged, which is laid along the bottom of the wall. All this is necessary to compensate for the thermal expansion of the concrete screed during the operation of the warm water floor system.

For large rooms, additional seams are also made. Here, in addition to the tape, thermal insulation for the walls also performs the function of compensation. In this case, the thermal insulation must have a thermo-repellent foil.

Number of screeds for underfloor heating

At first glance, a very strange question about how many screeds should be arranged for a floor heating system. In addition to the rough screed, an optimal screed for underfloor heating is performed over the pipes. The last layer will serve as the basis for finishing the floor in the room. An alternative to a rough screed is a floor slab. But in this case, it should be almost perfectly flat and free from defects. Otherwise, you will have to arrange a layer to align.

A warm water floor must be installed on a base without errors. It should be flat. This is necessary so that in the future the pipeline is evenly distributed in the concrete screed for finishing.

Underfloor heating components

The entire underfloor heating system, together with the screed, has a certain thickness, which should have optimal parameters. In this case, you should first decide what is generally included in the heating system of the subfloor and how thick each layer can be.

• Initially, a layer of heat and waterproofing is arranged on a flat base. Polystyrene is often chosen as a heater due to the qualities and characteristics it exhibits during operation. Usually, the thickness of the warm floor is taken here in the range of 80-100 mm. It is this layer that will be enough to retain heat and send it in the right direction. Even if there is a basement below without heating. Waterproofing will not affect the total thickness of the underfloor heating, since it is made of a very thin plastic film.

  

• Insulation can be purchased with special grooves for placing the pipeline. In its absence, you can arrange a layer of reinforcement or purchase a MAK mesh, to which it is very easy to fasten pipes. For a metal reinforcement mesh, the thickness is approximately the same as the mesh and is approximately 4-6 mm.
• The pipe itself, which is used for the water floor heating system. The diameter can be completely different. But it is recommended to take no more than 20-22 mm in diameter. It will be sufficient for the system to work fully.

• Screed over underfloor heating with a fine finish. It has its own subtleties of preparing a solution and choosing the appropriate material (cement, sand, additives, plasticizer, etc.). A layer for fastening (glue) is also added to the finishing coating, which refers to ceramic tiles.

  

Fill composition

First you need to decide on the brand of cement for the solution. It should be M200-M300, depending on the purpose of the room itself. In addition, the composition may include plasticizers to avoid the appearance of cracks on the surface after pouring, as well as better distribution over the base. When a screed is arranged under a warm floor, the thickness must meet all requirements and recommendations.

Usually it is 50-70 mm. The filling level starts from the top of the system piping. Manufacturers of dry mixes for the preparation of concrete mortar can also advise the optimal parameters. This should also be guided by the installation.

Instead of plasticizers, "folk" remedies in the form of PVA glue can also be used. Such methods were applicable 15-20 years ago, when technologies were not so well developed. It is worth noting that the cost of various supplements is currently not so significant and can be purchased. In addition, their consumption is not large for the volume of concrete solution. In this case, the thickness of the screed over the underfloor heating pipes can even be somewhat reduced, due to the improved strength characteristics.

Minimum parameters

Building codes stipulate minimum limits for screed pouring. This is spelled out in the relevant documents. But not everyone knows about what thickness the screed for a warm water floor can be.

The minimum thickness of the underfloor heating screed should be 20 mm, if self-leveling mixtures without a layer of reinforcement are used in the work. If this is a classic concrete screed, then at least 40-60 mm along with an arranged reinforcement layer. True, the metal mesh is not always laid over the pipes. This is done in the event that there is a desire to strengthen the entire structure and create reliable protection for the pipeline.

The minimum screed for a water-heated floor can be considered for execution with an arranged sub-layer, when the base is leveled and adjusted to a horizontal level. In any case, the pipeline should be laid on a flat surface without errors and defects. You can talk about the minimum thickness of the screed over the warm floor if you completely forget about the reinforcement. This layer should be skipped so that the distance from the ceiling to the floor is not affected. Currently, there are alternative options for metal mesh - fiberglass. Adding its insignificant size to the prepared concrete solution will allow obtaining the same characteristics without increasing the pouring layer.

The minimum layer of screed for underfloor heating will not work when stress is manifested during operation. This can be installed bulky furniture, household appliances, etc. All this can damage the surface and render the floor covering unusable. So you should know what thickness of the screed for a warm floor will be optimal, and in what conditions it will be used.

Usually, a layer of underfloor heating screed will be sufficient in 60-70 mm, together with any kind of floor covering. All quality and efficiency in work will be manifested here. The floor will be warmed up in the required amount with minimal heating costs.

Screed pouring limits

The thickness of the screed over a water-heated floor can reach a certain height parameter, while it performs its functions. Nothing is documented about this. No one advises to choose the thickness of the screed for a warm floor under the tiles no more than 15-17 cm. Otherwise, there will be only a waste of money to buy material, as well as time to complete the work.

The minimum screed thickness for a water-heated floor cannot be provided when a monolithic structure is created. That is, the screed over the floor heating pipes also plays the role of the foundation of the house. The situation is similar in specialized premises, which are more of industrial importance (garage, storage rooms, parking lots).

Since water underfloor heating is mainly arranged in private buildings, it is here that another problem appears - problem soils at the base. If they are available, parameters such as the minimum thickness of the screed over a water-heated floor cannot be considered. The fact is that if an insignificant level of filling is created, over time it can collapse and affect all components of the structure, including the pipeline with a floor covering. The system is installed for years, therefore, care must be taken to create the required layer of screed over the warm floor.

With significant unevenness of the surface, large differences in height, you should think about leveling it to the required limit. All protrusions are knocked off, and the remaining areas are covered with dry material. Such manipulations are carried out before the installation of a warm floor.

The use of a backfill layer allows you to reduce the cost of preparing a solution for a concrete screed.

After all, every centimeter of the pouring level requires a certain amount of concrete solution. The higher this indicator, the more expenses. One cubic meter of concrete for pouring a room area of 10 m ² and a screed thickness for a warm floor of only 10 cm.

If the minimum screed of the warm floor has not turned out, but have reached the maximum limits, then it is worth remembering the difficulties and problems that you will have to face during the operation of the system. The floor surface in the room will heat up for a very long time. On all this money will be spent to "heat" the entire "pie". Consequently, the effectiveness of the warm floor will be minimized or nothing at all. So, when the underfloor heating screed is performed, the optimal thickness should be selected whenever possible.

Recommendations from experts

Everyone wants to get an answer to what thickness of the screed over a water-heated floor will be the most suitable. In any case, it will not be possible to get a definite answer here. For this, the base of the floor is studied, all the requirements for pouring, as well as operational characteristics. There are tips from experienced craftsmen who claim that compliance with the following conditions will maximize the effect of an arranged underfloor heating system.

1. The minimum thickness of the screed over the underfloor heating pipe must be 50 mm.
2. Communications placed in the floor screed should be placed in a protective corrugation. The minimum thickness of the screed for underfloor heating, passing over the corrugation, should be 20 mm.

3. For certain rooms (corridor, bathroom, kitchen), the minimum thickness of the underfloor heating without a layer of reinforcement is 70 mm.

   

   If it is possible to increase the strength of the solution by using various additives, then the level can be reduced to 40-50 mm. The device of a reinforcing layer that strengthens the entire structure helps here.

4. For children's rooms, the thickness of the screed over the warm floor is taken in the range of 50-60 mm. Additionally, a soundproofing layer is added to the overall "pie".
5. All living quarters should, if possible, have the same screed thickness for warm floors and tiles. A low level is provided only for the bathroom to exclude the possibility of water spillage in the event of a pipeline failure.
6. When choosing the optimal screed thickness for a water-heated floor, you should focus on the door openings. When installing a thick layer, you will need an individual order of door leaves. This in turn leads to high costs.

Determining all indicators of a screed for a warm floor will allow a competent attitude and seeking help from specialists. Based on their experience, they can suggest the right choice in a particular situation. If you do it yourself, it will not be superfluous to watch a possible video, as well as adhere to the recommendations of the manufacturers of the material used for work.

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