Stela for a warm floor. Why is she no insulation?

Do you intend to equip your house with a warm floor system? If so, it’s likely that during your research you have encountered the term "stela." However, what is a stela precisely, and why is it generally advised against insulating? Let’s examine this subject in more detail to learn about the function of stela in warm floor systems and the reasons insulation might not be required.

Let’s start by defining a stela in relation to a warm floor. The part of a radiant floor heating system that produces heat is called a stela, sometimes referred to as a heating cable or heating element. It emits heat uniformly throughout the floor surface and is usually installed directly within the floor structure as loose cables or mats.

Why, then, is there discussion about stela insulation? Insulation has long been thought to be necessary for home heating systems in order to increase energy efficiency and decrease heat loss. However, the dynamics are slightly different in warm floor systems with stela.

The nature of radiant heating is a major factor in the possibility that stela in warm floor systems can function without insulation. Radiant floor heating warms the items and people in the space directly, as opposed to traditional heating systems, which warm the air. This indicates that there is minimal heat loss to the surroundings as the heat produced by the stela rises upward, warming the floor and everything on it.

Furthermore, covering stela with insulation may interfere with the system’s efficacy and efficiency. Heat can be trapped by insulation above the stela, which can cause the cables to overheat and shorten their lifespan. Furthermore, insulation may make it more difficult for heat to be distributed evenly across the floor, creating hot spots or uneven heating.

In summary, insulation is important for many aspects of home heating, but for the stela in warm floor systems, it might not be required or even wise. Making educated decisions regarding the insulation needs of their heating systems can benefit homeowners by having a thorough understanding of the special dynamics of radiant heating and the purpose of stela.


The components of the warm floor are as follows:

  1. Embanking plate (reinforced concrete)
  2. Waterproofing, since the slightest moisture below seriously worsens the thermal insulation properties of any insulation material
  3. Insulation (its task is to minimize thermal losses down and create the maximum heat stream up, t.e. into the room, which we try to heed by our water floor system)
  4. A warm floor pipe, from which a heat stream comes in all directions

The minimum thickness of the screed is 65 millimeters, and the minimum distance between the pipe’s upper edge and the screed’s edge is 45 millimeters. To reduce heat loss through the walls and account for the expansion of the concrete screed, make sure to lay along the room’s perimeter. The concrete screed breathes because the wall and it are not rigidly connected. As a result, damping tape should be used to separate it from the wall.

It is our responsibility to direct heat upward into the heated room and keep it from draining into the street’s basement. It is suggested that we install a substrate for underwear for this.

Varieties of insulation materials

The following kinds of insulation are used to stop heat loss:

Polistyle stoves with bosses

Both when there is and is not a coating, this occurs. The bosses on a plate that isn’t coated can easily come loose when installing a heated pipe. You can move carefully along coated slabs without losing bobs. However, the warm floor pipe that runs between them is not fixed, meaning that anchor brackets will need to be used for additional fastening. One square meter of coating slab typically costs 600 rubles.

Polistyle slabs with plastic coating

Such a slab has a 2 cm thickness and a plastic coating that makes it easy to move along the plate without the bosses getting in the way. Whether the pipe is made of stitched polyethylene, metal, or plastic, it is securely fastened between the bosses and does not protrude. Fixation doesn’t need any additional components. One square meter of such a slab typically costs 680 rubles.

Polistyal smooth slabs

Reduced density, 2 to 10 cm thick, 2 cm thick plates cost 100 rubles per square meter.

A warm flooring substrate with markings

Substrates beneath the heated floor, isolin, and foilizol are not heaters! Their thickness, made of foamed polyethylene, is 3–4 millimeters. The sole purpose is to make smooth plate arrangement more convenient.

In the realm of heating and insulating your home, the question often arises: why doesn"t a stela, typically used for warm floors, require insulation? The answer boils down to the nature of stelas themselves. Unlike traditional heating systems that rely on air circulation, stelas work by directly heating the floor surface, which then radiates warmth upward. This method minimizes heat loss because the warmth is concentrated where it"s needed most – at ground level. Additionally, stelas are often installed within a layer of concrete or directly under floor tiles, providing a dense and stable thermal mass that retains heat efficiently. Therefore, while insulation is crucial for conventional heating systems to prevent heat loss through ducts or pipes, stelas operate differently, making insulation unnecessary for their effective functioning.

What does saving on the insulation lead

As an illustration, consider a 50 square meter room.

Usually use polystyrene foam with bobes, the cost of 1 kV. meters on average 600 rubles, thickness – 2 cm. In most cases, this thickness is not enough for insulation, with the exception of the southern regions. Additional insulation up to 4 cm will cost another 150 rubles per square meter. The total amount will be 7,500 rubles. Savings on this amount is discussed when choosing insulation. The owner of the house seeks to reduce costs and often chooses the cheapest option – a substrate for a warm floor, instead of the insulation itself. Ultimately, the economical owner of the house heats the street and spends even more means to maintain a comfortable temperature in the room.

Calculation of the cost of water warm floors

In front of us are two premises:

  1. the first with normal, high -quality insulation of the required thickness;
  2. The second – with a underwear substrate for the warming floor and the "economical" owner.
Characteristic House number 1 House number 2
Paul Square 50 50
Pipe temperature 40 40
Pipe diameter 16 16
Insulation 60 20
Thermal stream up 73.76 65.81
Thermal stream down 18.88 58.72
The maximum floor temperature 26.82 26,18

Three times over, the heat flow into the room in the first house, with a 4 cm heater, exceeds the heat stream. The room is heated, not the street, with all of the heat that the owner pays for! The heat flux up (into the room that needs to be heated) in the "economical" owner’s home is nearly equal to the heat stream down (to the street, nowhere). One square meter’s worth of energy shoots "into the pipe" at forty watts.

  • On 1 square meter with a underwear substrate, we lose 40 watts, 50 square meters – 2000 watts.
  • 1 cubic meter of natural gas gives 10 kW of thermal power and costs 4.5 rubles (the price depends on the region, from 4 to 8 rubles).
  • 10 00 W/2000W = 5 hours – there are so many 1 cubic meter of natural gas for heat loss.
  • The boiler works an average of 12 hours a day. 12/5 = 2.4 cubic meters of gas spent per day on street heating.
  • 2.4 (cubic meters) x4.5 (ruble) x30 (days) x7 (months of the heating period) = 2,268 rubles per year.

7500 rubles divided by 2268 rubles equals 3, which is the payback period. Thermal losses will rise when the warm floor substrate is used! These substances are not insulators!

Refrain from substituting underfloor heating substrate for insulation!

When using warming materials with insufficient heat insulation for full heat insulation or when using foils, nunol (they are also a underfloor heating), the owner of the house loses a lot of heat in the lower direction. This is either an unreasonable savings or a serious misconception of the homeowner. Heat loss in this case is comparable to the heat flow entering the room. The use of high-quality insulation of the necessary thickness pays for an average of 3-3.5 years of operation of a warm floor, when used as a source of energy of natural gas. Natural gas is the cheapest energy source. If we talk about other sources, then the insulation can pay off for 1 heating period (t.e. for 7 months).

Issue Lack of Insulation
Problem Heat Loss

It may seem easy to install a stela for a warm floor in order to keep your house warm during the winter. It’s important to realize why it’s not a stand-alone insulation solution, though. The stela radiates heat upward, which helps to provide some warmth, but it cannot stop heat loss from the bottom.

This is due, in part, to the stela’s preference for heating nearby objects and surfaces over the surrounding air. A significant portion of this heat can escape downward in older or inadequately insulated homes if there is inadequate insulation under the floor. This implies that even though the space directly above the stela may feel warm, the room or house’s ability to heat as a whole is compromised.

Furthermore, the stela may need to use more energy to maintain the desired temperature if there is insufficient insulation, which would increase heating expenses and waste energy. Furthermore, discomfort and unequal temperatures throughout the room may arise from inconsistent heating brought on by heat loss.

A warm floor system must be used in conjunction with appropriate insulation for maximum effectiveness. To stop heat from escaping below, this involves putting in insulation materials beneath the floor, like foam boards or reflective barriers. You can make your home more comfortable and energy-efficient by adding insulation in addition to the stela.

Finally, even though a stela for a warm floor can help with localized heating, it shouldn’t be your home’s only insulation option. It’s crucial to combine the warm floor system with appropriate insulation measures for maximum energy efficiency and comfort. By doing this, you can guarantee constant warmth throughout your house and eventually lower your energy usage and heating expenses.

Video on the topic

Do you need a reflector for a warm floor in a screed? Experiment

Cement screed of a water warm floor. Warming for warm floor.

Foil in the warm floor works or not? Thermal conductivity of the screed, ordinary and half -dry.

4. Warm heater thickness. Types of thermal insulation. Warm floor from a to me.

How to choose a warm floor insulation. Life hack from the check.RF

Foil in warm floor! What the research says?

Once again about the underwear substrate!

A underfloor heating substrate: is it necessary, which one to use, how to put?

What type of heating you would like to have in your home?
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Michael Kuznetsov

I love to create beauty and comfort with my own hands. In my articles I share tips on warming the house and repairing with my own hands.

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