Infrared underfloor heating under plywood
In carrying out repair work, underfloor heating is already a matter of course. They are installed not only in houses and country cottages, but also in the most ordinary city apartments.
How to Plywood a Floor for Tiling
Underfloor heating on plywood is especially popular. This is due to the fact that it is possible to mount such floors without the involvement of specialized professionals, and the results and further operation can delight the owners for many happy years. In addition, this specificity of installation provides for the laying of underfloor heating not only in the standard version, but also with the coating on top of ceramic tiles, which is especially important in the kitchen, hallway and even in the bathroom.
Tips for the job
Depending on the choice of material for the underlayment, changes and installation method. For example with plywood substrate, the use of conventional dowels is not recommended. To ensure that the wood veneer can expand without hindrance when installing plywood, you should use mounting brackets.
This is especially true if there is a potential for moisture. This method of mounting allows you to install a floor heating system under the tiles with the full confidence that the substrate will not swell.
In total, it is possible to use several permissible options for the installation of the rough coating:
- If plywood sheets are mounted on a concrete screed, the material should not take less than 12 millimeters.
- In the case where the floor is wiring, pipes or other communications, it is more relevant to conduct the coating with the device of the lag. You can use 2 options for the device “black” floors, either a double coating of thin sheets, or a single layer of 2 centimeters thick.
- If as the basis are boards, or any other floor made of wood, the thickness of the plywood coating can be any. The main thing that it does not squeak and does not sag.
Specialist recommendations for plywood in underfloor heating
The material for the subfloor under the underfloor heating also determines the subsequent method of installation. For example, a plywood base assumes the absence of standard dowels.
It is necessary to use brackets for fasteners, thanks to which the wood veneer in the plywood sheet could expand without hindrance during thermal expansion.
It is especially important to consider this point in rooms where high humidity can occur. bathroom, shower, kitchen.
In this case, a warm floor on the plywood can be covered with tile or stone, and for many years of operation there will be no swelling and falling out of the decorative material in the floor covering.
Types of electric underfloor heating
While the water underfloor heating can be installed directly under the wooden floor, i.e. under the plank flooring, the electric one can be installed only under the covering made of relatively non-combustible materials. There are 3 main varieties of electric heating coatings of the considered type, each of which corresponds to its own power and type of finish:
- Heating cable. The range of operating power varies within 120-180 W/m2. As the final coating, it is recommended to choose porcelain stoneware or ceramic plates.
- Mats. Are analogous to the above modification, but with the difference that the heating conductor is fixed to the substrate. Therefore, in addition to the power of the heater itself, products are characterized by the pitch of its location on the substrate. Optimal option of finishing coating. tiles based on ceramic or granite.
- IR-emitting film. The working surface of the material radiates thermal energy on the principle of sunlight and heats the surrounding objects. Its wattage varies widely, from 150W to 220W per m2. Installed under parquet, linoleum and laminate.
Peculiarities of installation of underfloor heating cable linoleum
Calculate the required output of the floor heating and purchase the required cable length and thermostat. Make a diagram of the cable arrangement, taking into account that the distance between the coils must be at least 7.5 cm to the furniture. 10 cm and the heating devices. at least 20 cm. Choose a spot on the wall to place the thermostat.
After completing the installation of the cable floor heating system, a visual check of the integrity of all elements and their correct connection is made. After that, measurements of circuit integrity and insulation resistance are made with a tester and megohmmeter (insulation resistance should be at least 10 megohms).
Installation of electric cable system
No less popular in the organization of warm floors on the wooden floor are systems based on heating cable. This is a special conductor, when passing an electric current through which heat is released. Its laying is carried out according to the following technology:
- The installation of the support bars is carried out.
- Then on the free surface between them a material for the reflection of thermal radiation is laid.
- On top of this coating is laid out a special substrate under the heating cable. a galvanized mesh.
- Then the heating conductor is laid on it.
- All loose elements are fixed.
The choice of base materials and finishes, as well as the main devices should be carried out taking into account the following features:
- To avoid overheating of the wooden structure the maximum temperature of the heating elements should not exceed 400°C.
- The thermal conductor is distributed over the surface as evenly as possible. with the exception of places where furniture and interior items are installed. no heating elements should be under them.
- The thickness of the finishing coat directly depends on the type of its material and its heat-conducting characteristics. For wood, this value is 2-2.5 cm.
Arranging a plywood underfloor heating system
Installation of floor heating on a plywood base, in contrast to the traditional methods of laying, is done without a rigid fixation. Sheets of material are attached to this method of installation with fixing brackets made of metal. This allows the wood veneer to expand with increasing humidity, eliminates the appearance of bloating, cracks.
Layout of plywood for heated flooring
Several methods are used to install intermediate plywood flooring:
Attention! Plywood sheets are attached to the concrete with dowel-nails, adhesive mortar.
- On the basis of wooden beams are used thick sheets of thickness 2 cm in 2 layers with the seams apart;
- On old wooden floors any thickness of the material is used.
Tips when working
Depending on the choice of material for the underlayment, the installation method also changes. For example, with a plywood base, the use of conventional dowels is not recommended. In order that the wood veneer could expand freely when installing plywood should be used fixing brackets.
This is especially important if there is a risk of moisture. This method of mounting allows you to install a floor heating system under the tiles with full confidence that the subflooring will not swell.
In total, it is possible to use several permissible options for the installation of the subfloor:
- If plywood sheets are mounted on the concrete screed, take the material no thinner than 12 millimeters.
- In the case where the floor is wired, pipes or other communications, it is more relevant to conduct the coverage with the device beams. You can use 2 options for the device of black floors, either a double coating of thin sheets, or a single layer of 2 centimeters thick.
- If the basis are boards, or any other floor made of wood, the thickness of the plywood coating can be any. The main thing is that it does not squeak and does not sag.
The following recommendations are for the adhesive. For flooring, two-component or alcohol content versions are considered the most suitable. It is also possible to use a water analog, but only if the device is planned in rooms without high humidity.
It is also important to install the sheets not in their original form, but beforehand, cut them into 4 equal parts. This will help in the operation to avoid deformation and unnecessary stress.
When installing, do not lay the flooring against each other. Leave a temperature gap of about 4 mm between the sheets and about 8 mm between the floor and the wall.
As for tile floors, to the extent of their properties, such floors will in fact be cool. Additional coverage, especially when calculating the device of the floor heating, in the form of plywood will have a great effect on the comfort of operation. It is much more pleasant to walk on a heated and pleasant covering in the same bathroom than on a cold floor.
Filmed floor heating
The infrared emitter function is similar to that of the sun. Like sunlight, infrared radiation is absorbed by the objects which then emit heat into the surrounding area.
Thermal radiation is not absorbed by the air, it only dissipates it slightly. Almost all the energy of the emitter reaches the objects. walls, ceilings, furniture and other things, heating them.
Preparing the floor for the installation of heating systems with infrared emitters
Preparation of a warm floor in a wooden house for installation is possible in three ways:
Option 1. Used in very dilapidated flooring, when the floorboards creak underfoot, sag or fail in some places.
- dismantle the upper floor covering and the subfloor;
- check the condition of the beams, if necessary replace damaged parts;
- Expose the beams, carefully check the level, fasten;
- pour a cushion of expanded clay to prevent heat loss, let it stand for 2. 3 days;
- lay the subfloor, the gaps between the boards are allowed in 1,5. 2 cm;
- Treat the subfloor with antiseptic;
- Place parchment on the subfloor
- lay the flooring;
- the gaps between the floor and walls caulk installation foam;
- lay plywood on the floor, preferably 10-12 ply water-resistant plywood. Fix the plywood with screws 40-50 mm long along the perimeter of each sheet at a distance of 150. 200 mm between them. If in any place plywood breathes. additionally fix these places;
- Fill the gaps between the veneer sheets with putty;
- Before laying the veneer sheets, treat their lower sides with hot oil-varnish, and after finishing the laying, treat the entire floor surface with oil-varnish as well.
The floor will be ready for installation of the emitters in 3 days.
Option 2. Condition of the floor. individual boards are slightly loose and squeaky. Nail heads start to come out of the board in some places. The following measures are sufficient:
- To punch all the nails flush with the boards, in the creaking areas to strengthen the boards with screws about 80 mm long;
- Remove the baseboards;
- lay the plywood on the floor as described above.
Installing the film floor heating
An infrared ray emitter is available in the form of a film in rolls. It can be laid not on the entire surface of the floor in the room, it is quite acceptable to leave a gap to the walls of about 10 cm.
Important! It is forbidden to overlap thermal film.
The place for installing the thermostat should be chosen in the most convenient location, for example. as close to the wiring as possible.
It is better to lay the wires parallel to the wall, and tighten the copper contacts with pliers. Seal the joints with insulating material, insulate copper contacts with silicone sealant.
Connect the thermostat and fasten it to the wall in a convenient place. Switch on the thermostat and apply voltage to the emitters, and after a while check the heating of the sheets. If caught cold. check the connection points with a tester and fix the contacts that do not work.
Connect the grounding, using for this purpose foil tape, its end should be connected to the wire diagonally and along the length.
The whole floor must be covered with a layer of polyvinyl foam foil, and then you can lay the floor covering of your choice. laying over the foil is not dangerous, because the maximum heating temperature of the foil radiators is max. 40 oC.
About some rules of installation of the underfloor heating
- The floor covering has to be installed with a view to possible future repairs.
- It is strictly forbidden to use any metal fasteners. nails, screws, screws, staples, etc.
- If you are planning to install heavy furniture or equipment on an infra-red floor, it is necessary to provide for air s in advance.
- Do not install the film floor near other electrical heating devices. stoves, fireplaces, etc.
- The maximum length of one piece of film is 15 metres.
- Do not install the foil at subzero temperatures.
- Grounding is a must when installing and operating the floor heating in a wooden house.
All wires should be connected to the temperature controller according to the instructions