Insulation of underfloor heating pipes. The choice of insulation for underfloor heating. Mineral mats for underfloor heating
Looking for how to make a warm floor correctly? Would you like to delve into the process, and not rely on installers? Looking for underfloor heating? An overview of underfloor heating heaters is offered, it will be told what kind of energy effective insulation choose and why it is beneficial. Let's analyze the doubts about the choice and give two types of cost savings calculations to make the right decision.
Underfloor heating is used:
- for heating a cottage or a house without radiators, it is also possible to combine with radiators;
- for underfloor heating ceramic tiles or other materials and comfortable feeling to human feet.
Warm floor, based on this, it happens:
- water;
- electric.
Now we will talk about water systems floor heating and about their component - a heater for a water heated floor. We will also consider with calculations the effect of insulation on heat loss.
Why do you need underfloor heating?
Insulation is used during installation and provides maximum heat transfer from the warm floor. Thermal insulation must meet the following characteristics:
- Create maximum heat flow upwards.
- Ensure that there is no heat loss down to the floor slabs.
- Do not break down over time.
Imagine structural composition It consists of:
- Concrete base of floor slabs.
- Waterproofing.
- Lateral.
- Insulation for underfloor heating.
- Distribution of pipes with a heat carrier.
- Screeds with plasticizer.
- Floor finish.
The minimum thickness of the screed is about 50 mm.
Types of underfloor heating
The main types of insulation:
- Styrofoam board 2 cm without coating.
- 2 cm styrofoam board with coated bosses.
- Styrofoam 2-10 cm smooth plate with a quarter.
A foil substrate for underfloor heating with markings 3-5 mm thick is used during installation, but it is not a heater.
It is worth using a plate with coated bosses rather than uncoated ones. The cheaper coated slab requires additional anchor plates to hold the pipes between the bosses.
Smooth is interesting for its price and is used not only for underfloor heating, but also for warming the foundation, basements, building facades. Just on such smooth plates with a quarter, you can lay a foil substrate with markings and mount the pipe using fasteners.
Doubts about the choice of insulation
To remove all doubts by choice heater for underfloor heating Let's look at the financial side of the issue. To do this, we will calculate the warm floor of a room of 50 sq.m. All installers advise a 2 cm coated slab with bosses worth 600 rubles per square. The total cost of such a heater is about 30,000 rubles. If you add another 4cm smooth slabs with a quarter, then it will cost 150 rubles per square meter and in total it will be 7500 rubles. This amount of "savings" is what we are talking about. This is only a plus of 25% to the cost, but we will calculate what final result we will get. We will make calculations in the program for warm floors for two rooms:
- Room 1 - correct option choice of thermal insulation.
- Room 2 - standard version insulation.
Room 2
Let's start with him. We set the standard type of flooring under unheated basements, the pipe pitch is 20 cm, the room temperature is +20 ° C, the layers above the pipes and the layers under the pipes with 2 cm insulation. Heat carrier temperature +40 °С. After calculation, the program gives standard normative data, except for the downward heat flow, which is 58 W/sq.m., which is comparable to the upward flow. It can be concluded that with this option, the lower floor slab is heated.
Room 1
We set all the same data, only in the layers under the pipes we provide additional thermal insulation of the floor with polystyrene foam 35 density 40 mm thick. After the calculation, the program gives a result with an increased heat flux upwards and reduced by a factor of three to 18 W/sq.m. flow down. And this will give real savings in money.
On settlement room in 50 squares we lose 2 kW! If we translate this into money when heating with gas at average Russian prices for blue fuel, we get 2268 rubles. in year. The simple payback period for additional costs for more efficient insulation is 3.3 years.
Why you shouldn't skimp on floor insulation
In our calculations, we used the minimum cost natural gas for the consumer, If we consider more expensive sources of energy, diesel fuel or electricity, the simple payback period is reduced by several times and can be one heating season.
What are the other benefits of energy efficient heaters:
- They allow you to make excellent thermal insulation of the floor of a house or cottage, which leads to the overall energy efficiency of the house and brings its characteristics closer to passive houses.
- Raises the energy efficiency class of the house, which increases the value of the property.
- It makes it possible to install dispatching and control systems, including underfloor heating.
Main conclusions:
- When using heaters of small thickness, heat is lost in the lower direction. The heat loss is comparable to the heat flow up into the room.
- Insulation of the required calculated thickness pays off on average for 3 years of operation of a warm floor when using natural gas as an energy source.
How to choose thermal insulation
The choice of insulation can be made according to the following criteria:
- Recommendations from experts and sellers.
- Online reviews on YouTube.
- The price factor.
- Brand fame.
One of the main qualities of the future underfloor heating is not only comfort, but its efficient heat transfer and reasonable costs for heating the coolant. Insulation with a thickness of 6 cm or more will provide an energy-efficient solution for underfloor heating systems and will provide significant savings in just a few years.
Hurry up to make a smart choice!
What kind of insulation to put under the floor heating system? Let's find out what are the popular types of thermal insulation materials, their weak and strengths. I will talk about 5 options for insulation, which I personally used during the repair process.
Types of materials and their description
Popular thermal insulation for underfloor heating:
- Styrofoam;
- extruded polystyrene foam;
- Mineral wool;
- Penofol;
- Mats heat-insulating assembly for a heat-insulated floor.
Option 1 - foam
The most popular option due to the following advantages:
- Availability. The material can be purchased at almost any hardware store;
- Cheapness. The price per square meter is from 100 rubles per square meter;
- Large range of products. You can purchase material with a density of 15 to 35 kg / m 3 and a thickness of 20 to 200 mm. For use on the floor, I advise choosing options with a density of 20 kg and a thickness of 30 mm;
- Versatility. The material is suitable for water, infrared and electric underfloor heating.
The option also has disadvantages:
- Low material strength. At high loads on flooring the surface may bulge. To avoid this, it is necessary to make a screed of at least 6 cm;
- Installation inconvenience. It is difficult to tightly connect the sheets with your own hands, so the joints need to be filled mounting foam or fix sheets on the surface.
The process of floor insulation looks like this:
| Illustration | Stage description |
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Styrofoam is laid on the floor. The material can be laid without preparation according to concrete screed, slabs or rough wood decking. The most important thing is to place the sheets tightly so that there are no gaps between them. |
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Elements are fixed with dowels. Special fungi are used for fixing thermal insulation. All cracks are filled with cement mortar or mounting foam. |
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The film is laid.
The process is simple:
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Foil is covered for infrared systems. Reflective material can be used for other types of floors, but it is not required. Penofol is often used instead of foil, it creates a reflective surface and makes the surface even warmer. |
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A warm floor is laid on top of the insulated surface. It all depends on the type of construction. The surface is prepared with high quality and is suitable for any systems. |
Option 2 - extruded polystyrene boards
Extruded polystyrene foam or, as it is also called, Penoplex, is an improved version of polystyrene. Its main advantages are:
- High thermal insulation performance. Penoplex is 40% warmer than conventional foam plastic, which allows the use of thinner elements for insulation;
- High strength. Of all the thermal insulation materials that I talk about in the review, this one is the hardest and most durable. Therefore, Penoplex is ideal for rooms with a high load on the floor;
- Convenient connection system. The presence of grooves on the ends allows you to join the sheets very tightly. This increases the effectiveness of insulation and simplifies the work, you just need to combine the elements until they stop;
- durability b. The service life of the material is 50 years or more. Extruded polystyrene foam is not afraid of moisture, mold, chemical attack.
Of the significant disadvantages, one can be distinguished: high cost. A square meter of insulation 5 cm thick will cost you 250-300 rubles.
Installation instructions are simple:
| Illustration | Stage description |
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Penoplex is laid on the floor. The sheets are just tightly joined to each other. The elements are trimmed along the edges, narrow sections can be laid in pieces, after which it is recommended to carefully fill all the cracks with mounting foam. |
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Reinforcing mesh is laid A. If you are laying insulation under a warm water floor, then you can use this work option. It is simple, because you need to put a grid, and you can immediately attach underfloor heating pipes to it. It is convenient and reliable. |
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It is possible to lay reflective material under the reinforcing mesh. This option allows you to reflect heat into the room, so I recommend not saving and putting a layer of foil or Penofol on the surface. |
If you are laying an infrared floor, then the foil is not covered over the Penoplex, but over the screed, after pouring the surface under the heating mats, so the system will be much more efficient.
Option 3 - mineral wool boards
This version of insulation for underfloor heating system has the following features:
- High quality insulation. Mineral wool has good thermal insulation characteristics and is excellent for structures in which the most great importance has complete insulation of the cold surface;
- Compatibility with all materials. If polystyrene foam and extruded polystyrene foam are not very suitable for wood, then mineral wool is great solution in all cases. For wooden floors it is recommended to use mineral wool;
- Environmental friendliness. The material does not emit any harmful substances, is not damaged by rodents and does not support combustion.
The disadvantages are:
- High price. For a square meter of high-quality mineral wool 5 cm thick, you will have to pay around 250 rubles;
- Low moisture resistance. The material must be carefully protected from water, otherwise a fungus may occur over time.
The workflow looks like this:
| Illustration | Stage description |
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The surface is waterproofed. A polyethylene film can be laid on the surface. If you have wooden base, then it is better to put a vapor-permeable membrane. The material should go on the walls by 10-15 cm, the joints must be glued with adhesive tape. |
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Mineral wool is laid. The material is tightly packed on the surface. When cutting pieces, make them a little larger than necessary, this will allow the elements to fit tightly. Lay a damper tape along the walls immediately to create a deformation gap. |
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If you have wooden structure, mineral wool is laid between the beams. The material may be below the crate or be flush with it. Subsequently, the surface is covered moisture resistant boards and already on them the system of a heat-insulated floor keeps within. |
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Foil is laid on top of the mineral wool. The material is placed with laps of 10 cm at the joints and the obligatory gluing of the joints with foil tape. This results in a continuous reflective surface that is suitable for both water and electric underfloor heating. |
Option 4 - Penofol
This material is different from all the previous ones. Its main advantages are:
- Cheapness. For a square meter of material with a thickness of 5 mm, you will pay about 50 rubles;
- Ease. 40 square meters of Penofol weigh only 8 kg. It can be laid on any structures without weighting them;
- Efficiency. Foamed polyethylene has high thermal insulation characteristics. reflector with front side ensures the preservation of heat inside the room. That is, it turns out that the foil on the warm floor is combined with a heater;
Penofol - material based on polyethylene foam with a reflector on the front side
- Choice of options. The material may have a thickness of 3 to 10 mm.
The cons are:
- It is not worth using this option as a full-fledged heat insulator in the private sector;
- It is better to combine two materials, for example, extruded polystyrene foam 3 cm thick and Penofol 5 mm thick. This is quite enough to create a very high-quality insulation;
- For laying this material you need to prepare the surface.
The workflow looks like this:
| Illustration | Stage description |
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Lays on the floor waterproofing material . The film is glued at the seams and put on the walls to a height of about 10 cm, the excess is easily cut off later. |
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Penofol is laid on top of the film. It is positioned in the same way as the film. It is important to carefully straighten the material so that it lies without folds, and adjacent panels do not overlap each other. If you already have insulation installed and you need foil under a warm floor to create a reflective effect, then I recommend using Penofol instead. Due to the polyethylene layer, it is stronger and more durable. |
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Joints are glued special tape . This is a metallized adhesive tape with foil, which allows you not only to fasten Penofol, but also to create a continuous reflective surface throughout the room. |
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An underfloor heating system is laid on top of the insulation. It all depends on the option you choose. Next, the screed device is made. |
Beacons are placed on top of the structure and a screed is poured. The minimum thickness of the solution layer above the insulation elements is 30 mm, the maximum is 60 mm. This allows you to make the floor reliable and efficiently transfer heat from the system to the room.
Option 5 - special heat-insulating mats for underfloor heating
This option has the following advantages:
- Convenience. The product is a sheet of extruded polystyrene foam, in the upper part of which there is a profile with grooves or bosses for laying underfloor heating pipes. The size of the recesses is made for a standard metal-plastic pipe with a diameter of 16 mm, so the laying work is carried out very quickly;
- Choice of options. The thickness of the insulating layer can be from 20 to 70 mm. The configuration of the upper part may also differ, although this is not a fundamental point;
- Fast installation process. The work takes a little time due to the fact that you quickly and efficiently lay pipes, and then you can lay tiles or lay flooring without additional preparation. If desired, you can pour the screed, this also happens quickly and easily.
The disadvantage is the high cost, you will have to pay 300 rubles per square meter. But when you consider how much easier the process is, the costs are worth it.
The working process:
| Illustration | Stage description |
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The floor surface is leveled. For this, it is most often used cement mortar. The fewer flaws there are, the easier it is to lay a flat floor with minimal cost time. If plywood or OSB boards (oriented strand board) will be laid over the mats, then pay special attention to leveling. |
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Preparing damper tape. The roll is unwound, the protective layer on the adhesive strip is removed from the back, you don’t need to remove a lot, separate about a meter, then the film is removed as it is laid. |
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The tape is glued to the walls around the perimeter. The material is gently pressed to the surface, pay special attention to the corners. The tape is cut with an ordinary construction knife. |
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The first row is laid along the wall. The photo clearly shows that there is a special protrusion at the junction that tightly connects the elements and prevents them from moving, providing a reliable and even base for the underfloor heating system. Docking is carried out carefully so as not to damage the connection. |
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Laying is done over the entire surface. If a strip needs to be cut somewhere, it can be used on the other side, thanks to the connections, when using these mats, there is almost no waste left. |
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The pipe is laid. It is simply guided along the line, it is most convenient to push it with a light step of the foot. |
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The pipe is laid over the entire area. Thanks to the bosses, you can easily place the warm floor correctly and do not bend the pipe. Next, the floor covering is laid or the screed is poured. |
If it is not necessary to insulate the floor under the heating system, you can use mats without a layer of insulation. With their help, installation will be much faster than on an unprepared surface.
Conclusion
Using the review as an instruction, you can easily select the insulation under the warm floor and lay it correctly. The video in this article will help you better understand important points workflow. If something still remains unclear, ask in the comments.
By creating comfortable conditions in a residential area, it is necessary to strive for the heat to be distributed evenly throughout the entire volume during heating. Generally, following the laws of physics, warm air rises, while the floor remains the coldest zone. Often, temperature differences at the upper and lower levels of the human space are very significant. This creates discomfort and can cause colds. Uniform distribution of heat, constantly emanating from below, creates the necessary heat exchange. In order for the heating system to work effectively, thermal insulation for the warm floor is necessary. Today we will comparative review various thermal insulation materials.
The warm floor can be used both as an additional heating of the room, and by making it the main heating system.
- Reduces natural heat loss through the coldest surface in the room to the outside or into the ground. IN normal conditions the value of heat losses reaches 20% of their total volume.
- The radiated energy is evenly and rationally distributed around the heating perimeter. At the same time, it is not spent on heating floors and structural elements located below the heated area.
- Energy for additional heating is saved, the cost of heating is reduced.
- Additional sound insulation is created.
- Moisture from the ground or basement is prevented from entering the room through the floor covering.
Factors affecting the choice of thermal insulation
There are three main types of underfloor heating systems: water, infrared and electric. And the use of heat-insulating material directly depends on which of them will be installed. In addition, thermal insulation under a warm floor is selected taking into account the loads affecting the floor covering.
The main characteristics of materials for protection against heat loss can be considered:
- high compressive strength, elasticity;
- a slight degree of deformation when exposed to loads;
- resistance to aggressive environments;
- low thermal conductivity;
- high density (for floor insulation it must be at least 25 kg / m 3);
- minimum moisture absorption.
The correct laying of the thermal insulation layer guarantees the preservation of thermal performance during long-term operation
The main types of thermal insulation of a warm floor
Environmentally friendly dense natural roll insulation. The area of use is limited by the maximum height of the premises (when laying the material, the height of the floor is 3-4 cm) and the high cost of insulation.
Very important nuance - cork backing can only be used in combination with an additional ray-reflecting layer
Polypropylene
Polypropylene in the form of extruded boards: sound and thermal insulation coating with a closed cell structure. Not hygroscopic. Good for processing. Withstands temperatures up to 130°C. And they also use expanded polystyrene with an overlay in the form of a polypropylene film:
Styrofoam
Extruded polystyrene foam 50–100 mm thick: best thermal insulation for underfloor heating. Durable, Lightweight, Solid, inexpensive material, resistant to sharply negative and high temperatures and at the same time retaining its full properties during long-term operation. This is facilitated by the air filling of the cellular structure.
Expanded polystyrene is not destroyed in an aggressive environment. Does not absorb moisture and does not swell. Resistant to fungal attack, easy to assemble when laying.
Metallized lavsan film
Such a substrate as a coating of expanded polystyrene foam creates reliable protection from destruction of the floor when interacting with an alkaline environment cement-sand screed. Aluminium foil, without coating it with a high-temperature PVC film, is not used due to the instability of the foil layer to corrosion.
Underlayment to prevent heat loss must be laid over the entire surface to be heated, even if no heating pipes are planned to be laid in this place. This is done in order not to violate the integrity of the surface, to ensure the uniformity of the structure, to increase the reliability and strength of the coating.
Please note that whatever material is used as thermal insulation, a quality certificate must be issued for it.
The Expert Says: Testing Various Substrates
The right choice of thermal insulation will not only increase the efficiency of using the "warm floor" system, but also extend the life of all its elements, provide comfort and coziness in your home.