What Are The Requirements For High-quality Installation Of A Warm Floor

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

• Foundation preparation
• Drawing up a diagram
• Component calculation
• Thermal insulation
• Installing sensors and checking them
• Fixing the heating mat and cable
• Filling the screed
• Features of infrared heating

At first glance, it would seem that the installation of any option for a warm electric floor takes a long time and requires serious knowledge. But if you understand the technology and the sequence of all actions, then even a beginner in this industry can lay the heating elements. For this, there are certain instructions for laying a warm floor, which should be followed not only when choosing the components of the heating system, but also during installation work.

Foundation preparation

To begin with, you should pay attention to the base where the electric floor will be laid. If possible, remove the old coating together with the concrete screed to the floor slab.

This in turn will increase the distance between the ceiling and the floor in the room. Any resulting debris should be removed. Next, the rough screed is poured, necessary to give the surface horizontal evenness. The thickness of the solution is up to 3 to 5 cm.

When there are no special defects in the subfloor, then you can not waste time on a rough version of the screed, but proceed with further actions. But you still have to perform a screed to level out height differences, potholes or other defects. In this case, you will need to fill in the screed with a layer thickness of 30 to 70 mm. You can proceed to the next stage only after the leveling layer has completely dried.

Drawing up a diagram

Until the direct distribution of the heating elements on the floor surface in the room, it is best to sketch a diagram on your own, on which to mark the areas with furniture, the chosen laying step and other points that will play a significant role. This scheme will be useful in the future during the flooring, so as not to damage the heating elements.

When drawing up a scheme, you should pay attention to some points that will allow you to get a high-quality result:

• The distance from the walls of the heating elements must be at least 100-150 mm.

• Straight-line distribution of heating elements is optional. Even the heating mats (sections) can be cut in every situation. The main thing is that the heating cable is not damaged. These actions are carried out in order to rationally use the heating system, reduce energy costs, and also concentrate the main heating of the subfloor in the right places.

  

• In the presence of bulky furniture in the room, built-in furniture, as well as heavy household appliances that are not planned to be removed from their premises, the heating elements should not be laid. Heat transfer will noticeably decrease, therefore, warm heated air will return back. This will lead to overheating of the system in a separate area and will entail repair of the warm floor.

The step of laying the electric underfloor heating displayed on the diagram is calculated using the following formula:

h = (S * 100) / L

S is the occupied area of the heating elements.

L is the length of the cable or heating mat.

The minimum pitch for laying the heating section is 80 mm. But it should not exceed 200 mm.

Component calculation

It is worth calculating the required amount of a heating element based on what the heating in the room is used for. In the case of the main heat source of the heater power required 160-180 watts per m ². If this is an additional heating system working together with radiators or other sources, then it will be enough to select a power of no more than 140 W / m ². In the latter case, everything will depend on how the room is insulated and the presence of heat absorption sources (windows, doors).

Initially, the area of the base that will be heated is determined. This, as mentioned earlier, will not include the total area, the area of furniture and other stationary items. It is the resulting area that will be useful, on which the heating elements should be laid. As a result, it remains only to determine the total length of the heating cable or other element for heating the base of the floor, to determine its total power. Each meter of heating cable is usually between 16 and 21 W. This should be checked at the time of purchase.

A simple example can be given:

In a room with an area of 15 m ^2, it is required to create a heater with a power of 100 W for each square meter. So we get the total power that will be needed - 1.5 kW. If you choose a cable with a power of 20 W for each meter of cable, you will have to purchase 75 meters of a heating element. In this case, there should be no connections in individual sections, since the resistance will change.

The same principle of choice is characteristic of the thermomat. But besides this, mounting tape is additionally purchased. It will allow not only high quality, but also easier to carry out fastening of heating elements to the base (concrete screed).

Thermal insulation

Underfloor heating should transfer heat exclusively to the base of the floor in the room.

So that this is exactly the case and there is no heat loss to the rooms below, the installation of the heat-insulating layer should be performed with high quality. This will maximize the efficiency of the heating system as well as reduce energy costs.

The most optimal insulation option is penofol, presented in the form of rolls, having a foil coating. It is very easy to attach it to the base due to the existing self-adhesive layer. Bonding is carried out joint to joint. To avoid areas with gaps, all joints are glued with foil-based tape.

The heat-insulating layer should overshadow the walls somewhat. This will improve the thermal insulation properties of the entire room.

Alternative insulation options will only reduce the distance from the ceiling to the floor. In this case, you can purchase expanded polystyrene or polypropylene.

A damper tape is attached from the insulation on top of the wall. It is created to compensate for the thermal expansion of the concrete screed, as well as the floor covering during heating. So that there is no direct contact between the heating element and the insulation layer, a metal mesh is laid, which simultaneously serves as a reinforcement layer. It can be used for attaching a cable or heating mat.

Installing sensors and checking them

It is much easier to operate the system if the appropriate sensors and instruments are available. In underfloor heating systems, this role is played by a thermostat and a temperature sensor. All this allows you to set a certain temperature inside the room depending on the needs, as well as the time for turning on and off the system.

The sensors are installed in the wall, near the socket at a distance of at least 30 cm from the base of the floor. But the temperature sensor is mounted in the floor itself. For this purpose, from the place with the thermostat perpendicular to the base, a strobe is made in the wall, which drops somewhat to the floor. A corrugated pipe is initially placed in it, into which the temperature sensor is placed. It should be noted that the sensor in the corrugation should not intersect with the heating elements, but be located between their turns. To prevent the solution from entering the corrugation, all holes are sealed with a sealant.

Before laying the heating cable, the resistance is measured, which must correspond to the passport data. Only a slight deviation of no more than 10% is allowed. Here a multimeter will be an excellent assistant. If everything is correct, you can start distributing the heating elements, according to the previously created scheme.

Fixing the heating mat and cable

When all the above steps are completed and the surface is completely ready, you can proceed to the correct laying of the floors, or rather the heating element. A mounting tape is perfect for the cable, to which each element of the underfloor heating structure is attached.

If there is a reinforcing mesh, then the cable is attached to it using special plastic clamps. This is very simple and fast to do. The main thing is that the order of laying the warm floor is observed. The same steps are performed when laying the heating mat. But there are rules and requirements here:

1. You should trust the recommendations from the manufacturer to choose exactly the option that is necessary for a particular room.
2. During installation, as well as when cutting, you should carefully monitor the condition of the heating cable. It must not be damaged.
3. If the room temperature is less than -5 degrees, then it is better to postpone the installation and laying of floors.
4. It is better to entrust the connection of the mats to the network to specialists (an electrician).
5. The thermostat allows you to automatically disconnect the heating mats from the network. You can't do without it.
6. The mats should not stretch under force. All these external influences will damage it.

7. Creation of cable grounding.

   

Pay attention to the distance between the turns. It must be kept identical over the entire subfloor area of the room. The contractor is only required to properly decompose the heating elements and then connect them to the thermostat and other components.

All parameters of the cable resistance, as well as the correct connection, should be checked after installation.

Filling the screed

The mixing ratio is very important. Without their strict adherence, it will not be possible to obtain the desired result. If there is no desire to independently prepare the material for the screed, then you can buy a ready-made version in the store - dry mixes containing all the necessary components.

When self-mixing, the components should be selected based on the following proportion:

• 1 part cement.
• 4 pieces of sand.
• 5 pieces of crushed stone.

• 5 parts of water (you should be careful with water, as a very liquid solution is well distributed between the heating elements, but it will quickly crack and fail during operation).

  

• 01 part of the plasticizer, which gives the solution elasticity and strength.

Components such as perlite or expanded clay should generally be kept away from the mortar for underfloor heating. They not only disrupt heat exchange, but can also lead to overheating of the elements of the underfloor heating in a separate area.

The screed layer of a warm floor is usually 30-50 mm. It is within these limits that you should work in order to get the best efficiency of the heating system. Complete drying of the solution is carried out within 28 days. During this time, you cannot turn on the warm floor and start it up.

The concrete screed is used only over the heating cable. The heating mat no longer requires such a serious external load. For him, instead of a screed, a layer of tile glue is enough, which dries much faster. You can install ceramic tiles immediately.

Features of infrared heating

For infrared underfloor heating, special attention should be paid to the preparation of the base, or rather its high-quality leveling. Only a slight deviation from the horizontal line is allowed (about 1 mm per 2 meters of area).

When laying underfloor heating, one must not forget about the flooring of the thermal substrate, which can be polyethylene foam, with a layer thickness of 3-4 mm. Be sure to have a foil cover on one side.

If you need a high-quality distribution of the film floor, you can cut individual sections. But this should be done exclusively in specially designated places. For this there is a dotted line with a "scissor" image. These areas are subsequently insulated with bitumen insulation. It often comes together in a set of IR underfloor heating. Also, during installation, the distance from the walls in the room must be maintained, which is at least 100 mm.

Infrared stripes are laid on the substrate.

A gap of 5 to 10 mm is maintained between the strips. Instant failure of the heating element is guaranteed if it is bent at an angle of 90 degrees. Wires with voltage current are stripped at a distance of up to 10 mm with a special knife so as not to damage the wire itself. The resulting contact is placed and clamped in the terminal. When everything is done, it is insulated with bitumen insulation.

The infrared floor heating is characterized by parallel connection. For this, copper cables with multiple conductors are used. The cross-section of the cable must be at least 1.5 mm ². All other components (temperature sensor, thermostat) are connected without fail for high-quality operation of the heating system.

As a result of all these actions, a full-fledged "cake" is obtained, from which heat is transferred within a maximum of 30 minutes after turning on the network. The only feature is the infrared warm floor, when the flooring and interior items in the room are warming up, from which heat is already transferred to the air. Installation does not take much time and money. The main thing is to clearly follow the existing instructions for installing a separate component taken.

Video:

Video:

Video:

Video: