How to make a heated floor in the bathroom with your own hands: a step-by-step guide

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Irina Zhirova
Last update: April 2019

Warm floors are still considered a rarity in bathrooms, but they are no longer surprising. They give coziness and comfort. Every year the number of people wishing to install such a heating system is growing. Everyone knows how unpleasant it is to stand barefoot on an ice tile, and next to a bath or shower, the floor is also constantly wet.

We will talk about how best to make a warm floor in the bathroom, point out and warn what you need to pay close attention to. In our proposed article, methods of construction of all acceptable electric and water types are analyzed. Independent wizards will find detailed manuals on how to install and connect systems.

Varieties of underfloor heating + their features

What to prefer - heating systems water or electric? It makes no sense to burn kilowatts of electricity to heat the floor in a house with a powerful heating boiler. It will be more rational to make some changes to the existing heating system in order to direct the hot coolant into the pipes located in the floor.

Of course, it is best to think about connecting a warm floor even at the stage of heating design. But even in the working system, it is easy to find a point at which it will be possible to break the pipeline to insert an additional distribution comb.

It distributes coolant flows and is called a collector among engineers. Each flow is directed to a separate heating circuit, the floor is heated by several such circuits. All of them are connected to the collector, the coolant is supplied to the collector using a special circular pump.

If the floor area in the bathroom is small (up to 5 square meters), then you can refuse the distribution comb and pump and use shutoff taps and a temperature regulator. In large rooms, this equipment is indispensable: the boiler will consume too much energy and floor heating will have to be recognized as ineffective.

Arguments for choosing the most suitable under floor heating, which is most often used in the arrangement of a hygiene room, is given in the article we recommend.

Warm water floor
In the bathroom, it is allowed to lay on the floor not every coating, and the water floor even more tightens this selection. The material must be with a heat transfer resistance index of up to 0.15 sq. M. * K / W. This corresponds to ceramic and stone tiles. See product label for underfloor heating

In electric floors, the heating “core” are:

  • heating cables, mats;
  • infrared carbon emitters.

Heating cable or mat? The fundamental difference is seen in the complexity of laying and the height at which the floor rises.

For a heating mat, a layer of thin tile glue above itself of 3-4 mm is enough, so that the tile on the floor instantly gets warm. The cable in the mat is fixed to the nylon mesh with a given step.

Warm electric floor
Operation of a warm electric floor (like any other electrical device) implies compliance with safety measures. In order for the cable to be used in the bathroom, it must have an IP67 protection standard. The temperature controller can be moved to an adjacent room

If you use a cable, not mats, then you have to lay it on the floor manually, the installation step is set arbitrarily. From above the cable is poured with a layer of DSP 30-50 mm thick. The smaller the pitch, the colder the room can be heated.

The cable heats the floor longer, but such heating can be used not only as additional, but also as the main one. Mats do not cope with this task. In addition, they have a higher price.

However, the industry also produces a thin heating cable, which does not need to be covered with a solution of up to 30-50 mm. On such a cable, as on mats, you can immediately apply tile adhesive, but at the same time it is possible to adjust the pitch of laying. As a result, the advantages of both cable and heating mats are brought together.

Now about infrared heat ... If we all had an idea about electric cables before, then infrared heat is a novelty. In this case, we are talking about a two-layer thin film, inside of which lies an even thinner carbon crystal lattice emitting in the infrared range.

Film underfloor heating is no better and no worse than electric cable. They have their own scope.Infrared film better suited for dry installation under a parquet board, laminate without the use of mortar and glue, which do not adhere well to its smooth surface.

therefore tile infrared in the bathroom - a very dubious decision, despite the fact that manufacturers allow it to be used in wet rooms (bathrooms, showers).

Warm infrared floor
If you use infrared film in the bathroom for full heating, you need to cover at least half of the floor with it or additionally install the same wall panels

There are other reasons not in favor of the film. The width of the area on which it is laid should be a multiple of the width of the film itself. Otherwise, either the entire area will not warm up, or it will be necessary to lay the film in pieces, apply voltage to each piece separately, connect many contacts manually. All this reduces the reliability of the design.

Heating mats also have a standard width, but it’s much easier to close the area of ​​any size and shape by cutting the grid to which the cable is attached, but without damaging it. In terms of electrical safety, cable underfloor heating also wins, because they have a ground loop, but heating films do not.

So, if you do electric underfloor heating in the bathroom, then on the basis of cable or mats. It is easy to assemble such a heating system, it is enough to own the basics of electrical engineering knowledge. Mounting a water floor is much more difficult.

And what else gives us comparison of electric and water floor? The screed-mounted heating system with water circulating through the pipes is prohibited for use in apartment buildings because of its solid weight and the risk of accidents. Perhaps the device is only on the first floors, and then after receiving a bunch of permits.

Connecting to a central heating system is also not an option, even for apartments on the ground floor. Where can I get the coolant in this case? From the heating riser.

But having done an additional way through the bathroom, the water will return to the same cooling tower. Apartments located lower floors will not receive their heat, their owners will rightly begin to express dissatisfaction. Yes, and in the summer the floors will not warm.

Electric floor device
In the bathroom, it is recommended to use a two-wire wire in the electric floor. A single-core with two ends is connected to the network, and a two-core - with one. An insulating sleeve is put on the other end. You can lay out a two-core cable on the floor as you like, but a single-core cable must be returned to its original point

By electric heating circuits there are no such prohibitions. Once there is no water in the system, then flooding is also excluded - incidents that bring a lot of trouble to both the perpetrators and the victims. The device does not use as powerful and heavy screed as is required by water varieties.

And again, back to the need to raise the height of the floor. In the variant with an electric floor, its level, as mentioned above, rises by 30-50 mm. And with water - 80-100 mm. I don’t want to build too high a podium, but a water-heated floor is more economical during operation compared to an alternative electric option.

Steps for building an electric floor

Before buying a heating cable or mat, we focus on the free area of ​​the bathroom. We do not take into account the area under the bowl with a screen, a shower, plumbing furniture, a washing machine, a washbasin and a toilet. There is no point in heating elements for these items. Moreover, the cable will overheat and fail in such places.

Power electric floor in the bathroom

The standard floor power for bathrooms is 170-180 W / sq. meter. This norm is multiplied by the laying area. For example, the total area of ​​the bathroom is 5.5 square meters. meters. Minus the area occupied by various objects, we get, say, free 3 square meters. meter.

We multiply the average standard value of 175 by 3, add a reserve of up to 10% to the result and get 525-575 W / sq. meter. This is the required power of the floor heating elements.

Installation Instructions for Cables and Mats

Preliminary calculations make it possible to buy components and consumables in the required volume, after which you can safely proceed to the system design.

Step 1. We clean the base from debris, remove the dust with a vacuum cleaner, smooth out irregularities (1-2 leveling bulk layers are enough).

Step 2 We install thermal insulation. Heat-insulating sheets must be laid on the floor with the reflecting surface up and the joints between them glued with mounting tape (duct tape).

Thermal insulation of electric floor
Penofol is suitable for thermal insulation, and on the ground floors it is recommended to make the thermal insulation layer thicker using polystyrene foam and polystyrene. But in any case, the front surface must be reflective so that the thermal energy goes in the right direction

Step 3 Waterproofing. We roll out a film or a rolled waterproofing membrane, carefully level it and press it to the base, raise the edges on the walls (20 cm). If you have to use several panels, then we put them with an overlap of 10 cm, fasten the joints with tape.

It is allowed to use both coating and cast waterproofing in several layers. Each previous coat must be thoroughly dried before applying the next.

Step 4 Edge processing. We fix a damper (edge) tape along the walls along the perimeter.It is needed to create a “floating” screed in order to avoid the appearance of cracks and swellings on it. The tape should be taken up to 20 cm wide so that it is sufficient for the height of the floor, including the tiled coating.

Step 5 Laying the cable (or mats). We check the working condition of the cables and start laying. The heating cable is placed on a substrate to which it can be attached.

In this quality, a metal mesh is suitable. In addition to fixing, it will not allow the cable to sink into the screed and provide strength. We observe that the cable does not cross. We handle it carefully to avoid even the smallest damage.

The end of the heating cable is connected to an electric coupling. It will be necessary to drown it in the screed, while placing it as close as possible to the thermostat (thermostat), but keeping the distance between the wall and the connection at least 20 cm.

It is much easier to spread an electric mat on the floor. The process is somewhat reminiscent of cutting fabric.

Installation of electric mats
If the electric mat rests against an obstacle (wall, etc.), it can be cut with scissors or a knife along the supporting grid and deployed at any angle or in the opposite direction. The section from the section must be moved away at a distance of at least 5-6 cm

Step 6 Install temperature controller with a sensor. In the right place on the wall a meter above the floor, drill a hole, guided by the dimensions of the thermostat.

From it, vertically downward, we drill a longitudinal gate and continue it along the floor towards the location of the sensor. It is advisable to place the sensor between the cables, and not close to one of them, so that it shows the temperature reliably. The distance from the wall is half a meter.

The sensor with the wire is placed in a corrugated pipe. Corrugation will protect the equipment. In the same corrugated tube we start the wire from the heating mats and direct both wires to the thermostat.

To do this, we stretch the corrugated pipe along the floor, put it on the wall in a stroba, try not to bend it strongly at the joint between the floor and the wall, so as not to damage the wires. When the screed is filled in, the corrugated tube with the sensor should protrude slightly from it.

Checking the operability of the electrical system
When laying a warm floor, the resistance of the mat is checked with a multimeter. 5-10% deviation from factory figures is allowed. Also check insulation resistance. If the megohmmeter is at least 10 megohms, the mat is reliable

Step 7 Screed. Installation is moving towards completion, so once again we examine all the elements of the cable floor, make sure that there are no defects, and proceed to pouring. We prepare the cement mortar and distribute it on the surface carefully and evenly with a minimum thickness of 3 cm. There should be no voids in the screed. If mats have been laid, skip this step.

Step 8 The final touch remains - stick the tile onto the screed or directly onto the mats with tile adhesive.

This is followed by a long drying period. It will be possible to turn on the electric floor no earlier than 28-30 days after completion of work. It is necessary to wait until the mortar and glue completely dry so that the screed does not crack.

Tips for laying infrared film

Preparatory work - as in the previous version. The infrared film is laid in parallel sheets on a heat-insulating material. Overlapping sheets are strictly prohibited. Next, you should install a thermostat with a sensor and make sure that the system is working.

The assembled structure is covered with polyethylene and reinforcing mesh. Fix the mounting grid with self-tapping screws, but carefully so as not to touch the contacts. The mesh on top must be filled with a cement-sand screed and once again test the system. After the screed has dried, they lay the tile on the glue.

Laying infrared film
The infrared fabric in the bathroom is laid out on the floor, retreating at least 20 cm from the walls and with an interval of 30 to 50 mm between the strips

The infrared floor can be tested no earlier than after 28 days, when it is guaranteed to dry.

Water system construction

Do it yourself warm water floor in the bathroom - the task is more complicated, but why not try to cope with it ... We have to assemble a structure from pipes and connect them to a source of hot water.

Metal-plastic and polyethylene pipes are suitable for the pipeline. Both materials are flexible and have low hydraulic resistance.

Thorough theoretical training

One heating circuit can cover an area of ​​up to 20 square meters. meters, which is enough for the bathroom, but if the floor is planned to be divided into autonomous zones, then water must be supplied to them through distribution manifold.

Manifold for underfloor heating
Collector assembly consists in connecting all its sections to the pump and mixer, installing thermometers, taps, air vents. After that, the assembled distributor can be fixed to the wall and pipes to it

The collector must be with flow controllers. With the same water supply to different length circuits, they will heat unevenly. A longer circuit will get worse. Moreover, the flow of water in it may even stop due to strong resistance. To eliminate these troubles, flow regulators in the manifold are used.

Scheme of work of a water heat-insulated floor
A faucet is also a must. The maximum floor heating temperature is 50 ° C; water is supplied to the heating radiators at higher temperatures. If you take water from the general heating system to the floor, then it must be diluted with cold water to the desired temperature, which the mixer does

A number of strict conditions in order to proceed with installation:

  1. The presence of a closed heating system using a circulation pump.
  2. The double-circuit boiler must have a power reserve.
  3. All work is carried out with the heating system turned off completely.

Pipes must be freed from the coolant.

In the thickness of the warm floor, one can distinguish the required functional layers:

  • base;
  • hydro and thermal insulation;
  • pipeline fromdurable pipes;
  • concrete screed or gypsum fiber;
  • decorative flooring.

In wooden houses you can also make water floor, but you should worry about reliable waterproofing. It needs to be made in several layers, only this way the wooden base of the floor will last for many years without repair.

Water Floor Installation Step-by-Step Guide

The construction of the water system is a cycle that includes standard types of work.

Stage 1. We clean the floor, if necessary, remove the old coating.

Stage 2. Waterproofing the floor. On the floor we lay a waterproofing film. It is desirable in one piece, but if there are several strips, then they must be overlapped and the seams connected with a blowtorch. The waterproofing material should also capture the surface of the walls (up to 10 cm up).

Stage 3. Pour a rough screed with a mixture of expanded clay and cement (thickness 3-5 cm). Dry thoroughly (up to a week), in the first days spraying the surface with water to prevent cracks.

Stage 4. We warm the surface with polystyrene, polystyrene or other similar material. On top we spread polyurethane with a foil reflective coating. We glue the joints with tape. Now the heat from the pipes will be directed only towards the room.

Stage 5. We lay the pipes. We bend them according to the developed scheme, maintain in the spaces between the pipes of 15-20 cm. We fix the curved structure. We connect the water supply pipe to the flow distributing collector.

Pipe laying with a snake
Pipe laying with the “snake” is the most common. An alternative is laying with a “snail”. The first option is easier to install, but gives uneven heating. In the second embodiment, the heating is generally more uniform, but there may be cold sections of the floor, since there are reverse turns between the supply turns

Stage 6. We turn on the coolant supply and check if there is a water leak in the system.

Stage 7. We make the second screed with the same solution as the rough one.If roughnesses of up to 5 mm were allowed in the rough screed, then now we pre-install the laths-beacons to perfectly level the surface.

Finish screed water floor heating
One of the purposes of screed underfloor heating is the accumulation of heat. With a thick screed near the water floor, heat storage is higher

The final layer of the screed dries 5-7 days - as much as the rough one. After complete drying, you can begin to finish the floor and lay the floor tiles.

Conclusions and useful video on the topic

Video # 1. Visual demonstration of the steps to install an electric mat:

Video # 2. The process of installing and connecting an electric cable floor:

Video # 2. Rules and stages of installation of pipes for water floor heating:

Today, every family can make warm floors accessible, and a bathroom with such floors will be transformed and become more comfortable. The underfloor heating system will last a long time if technical inspection and preventive maintenance are performed in a timely manner.

And what kind of heating floor is arranged in your bathroom? Tell us about how to choose the best option for you, how to stack and connect the system. Please write comments in the block below, post a photo and ask questions about the topic of the article.

Was the article helpful?
Thanks for your feedback!
No (12)
Thanks for your feedback!
Yes (69)
Visitors Comments
  1. Denis

    In general, I think it would be better to put an electric underfloor heating. Water heaters are powered by heating (if you live in an apartment), but it is only in the cold season, and it is allowed to the device only on the first floors. You can, of course, put it if you have your own boiler, or you live in a private house. And the electric version can be turned on or off at any time, and it’s not particularly energy-consuming, it won’t work for you around the clock. The most optimal is to discuss the device project with knowledgeable people and entrust the work to specialists.

    • Sveta

      Do you really need a warm floor in the summer, when it's so hot? Most people at this time are looking for coolness.

  2. Andrew

    I tried to independently make a warm floor in the bathroom, but then I decided to turn to specialists for help, because I realized that my knowledge and skills were not enough. The specialist, like Denis, advised an electric version of a floor-mounted heating system. Firstly, it is built easier, and secondly, in high-rise buildings it is allowed to use only one. In general, they installed an electric floor, and I do not regret it.

  3. I want to make an electric heated floor in the bathroom, but I am afraid for safety. All the same, there is a shower and a washing machine, water leaks are quite likely. What is the best waterproofing for the bathroom? And is it not dangerous in principle?

    • Expert
      Alexey Dedyulin

      Hello. Electric underfloor heating is installed in humid rooms in compliance with the conditions of grounding, the installation of machines and RCDs. The wire should also be protected by a special coating, and best of all, immediately buy a cable designed for installation in such rooms. TP do not lay under shower cabins.

      For safe installation, it is advisable to initially invite an experienced electrician with a tolerance that will advise you everything, help you choose, install the system and connect it.