Finishing work

I want to make a renovation! Bathroom: safe and comfortable floor (part 2)

The bathroom is ready for renovation. It is empty, clean and somehow unusually spacious. Dismantling is done, garbage is removed. Repair work can begin. Today we’ll talk about how to repair the floor in a prepared room. What technologies should be used to make the floor reliable, beautiful and easy to use?.

Screed – the base of the floor

Why do you need a floor screed? She has several tasks. First of all, with the help of a cement screed, the floor is leveled, smoothed and turned into a base for finishing. A monolithic concrete or cement layer on the floor increases the level of sound insulation. This is especially true in apartment buildings, in an apartment located above the first floor..

And on the ground floor and in a private house, a screed is one of the methods of insulation. Another screed is a way of arranging the system «Warm floor». It protects heating elements, makes it possible to carry out high-quality finishing work, accumulates and evenly releases heat.

Waterproofing is needed under the screed

Waterproofing the bathroom floor is required. In some cases, it is done under the screed, and in some – from above. If you intend to install any system «Warm floor», waterproofing is done under it. If the floor is not heated, then the screed waterproofing will protect the concrete from excess moisture.

Waterproofing is different. For example, roll materials are rolled out over the entire area of ​​the bathroom, overlapping seams are soldered together. Rolled waterproofing products include roofing material, roofing felt, various films. Various mastics (bituminous and synthetic), epoxy resins can be classified as lubricants for waterproofing.

In a room where water can spill onto the floor, it is advisable to combine waterproofing methods with each other. So on a layer of bituminous mastic, you can lay a layer of roll material, and on top process it with another 1-2 layers of mastic. Waterproofing materials need to process the angle of abutment of the walls to the floor and the lower part of the wall.

DIY bathroom floor screed

You need to start, as always, with planning and layout. The level of the new floor is marked on the walls. It is better to do it with a slight slope, 1.5-2 degrees. This slope is not noticeable either visually or when walking. But he will do the owners a good service. If water accidentally spills on the floor, it will not flow into hard-to-reach places.

How high will the new screed be? If facing with ceramic tiles is planned, 10-15 mm must be subtracted from the floor level. This is the thickness of the tile itself and the layer of adhesive mixture used for laying it. System «Warm floor», if needed, it should be under or inside the floor screed. It depends on the thickness of the concrete layer. The total thickness of the screed should not be less than 3 cm. How to proceed if it is decided not to equip a warm floor? The base for a new cement (concrete) screed must be primed with a ready-made deep penetration primer. Then beacons are installed at a distance of 70-80 cm from each other. With the help of a building level, the horizontal level of the floor and the uniformity of a slight slope are checked. All beacons must be in the same plane.

For the screed, concrete is used (if the total layer thickness is 5 cm or more) or a cement-sand mixture (for a thinner screed). Concrete is composed of cement, sand and gravel. To get a high-quality mixture, you need to thoroughly mix the components in a ratio of 1: 2.5: 3.5-4. That is, 2.5 buckets of sand and 3.5-4 buckets of gravel are taken on a bucket of cement. The cement-sand mixture is sold in bags. The required proportions in the finished mixture are observed by the manufacturer. You can do it yourself. For one bucket of cement, you need to take three buckets of sand.

The prepared mixture fills the space between the two beacons and leveled it out with the rule. So gradually fill the entire floor area. After half an hour or an hour, the surface of the dried screed must be wiped off. It is better to pull out the lighthouses from the frozen, but not yet fully strengthened screed, and fill the formed cavities with cement mortar. This is especially important if the floor will not be covered with tiles. For example, if the owners want to make a new-fashioned polymer flooring. It is better to leave the finished floor covered with plastic wrap for several days. If the screed is not allowed to dry out, then cracks will not appear on it..

Warm floor in the bathroom

If we remember that we often stand on the bathroom floor with bare feet, then it becomes clear that a warm floor is very pleasant. Having once assembled the system «Warm floor», the owner will improve the microclimate in this room for many years. The heated floor will always be dry and the air not too humid.

Which of the three types of system «Warm floor» to choose for a bathroom? They are all good, but each has its drawbacks. To make a choice, you need to learn about all three.

Water heat-insulated floor

Electric underfloor heating

The system is a structure made of metal or plastic pipes through which water flows from the heating system. The pipes are closed with a coupler, and then with any finishing material. The thermostat allows you to control the degree of heating.


Not too expensive system. Does not require additional costs during operation. Absolutely safe.


Difficult to mount. In the bathroom, it makes sense only if there is a heating riser (if the heated towel rail worked from heating, not hot water). Requires thicker screed than electrical systems.

How to install? There is no need to make a screed for this option of underfloor heating. It is necessary to trim the concrete slab and make high-quality waterproofing. After that, the floor is insulated with expanded polystyrene plates or other dense insulation. A heat-reflecting screen should be placed on top of the insulation. It is needed so that the thermal energy heats our floor, and not the floor slab. A reinforcing mesh is laid on the screen – the basis of the future screed. The mesh on the grid should be small. No more than 50 mm.

Special pipes for a warm water floor are laid evenly, with a step of 100-150 mm. They are fixed on a reinforcing mesh. There is no need to lay pipes in the places where the washing machine or furniture is installed. The beginning and end of the pipe must come out of the floor in the place where the heating riser is located. You can connect the laid pipe directly to the heating pipes. At the same time, the new floor will work. But the owners will not be able to manage it. In order for a person to influence his work, the pipe is connected to special equipment. It includes a manifold, thermostat and special taps.

After laying the pipe and checking the operation of the system, beacons are carefully placed and a screed is made. The main task is not to damage the floor structure.

Electric underfloor heating

The system heats the floor using electric heating elements. Installed under a cement screed or directly under a tile. The temperature can be adjusted.


Very easy to assemble. Takes up less space. This is important if a high volume screed is not possible..


The system is not cheap to purchase and to operate. They emit a small amount of electromagnetic radiation during operation..

How to install? You need to install an electric warm floor on the same insulated and reinforced base as when installing a water one. You can use a special heating cable and lay it out on the floor yourself, following the instructions. And you can buy ready-made heating mats, where the cable is already laid out with a snake and fixed. Installation of mats is much easier.

The thermostat of the electric underfloor heating is installed on the wall. The connection wires are brought out to the heating zone and there they are connected to the electrical system. After checking, the electricity must be turned off, and carefully screed.

Film (infrared) warm floor

Film warm floor

The system consists of a heating foil that is electrically supplied. The kit includes insulators, temperature sensor, thermostat.


Easy to assemble. Very thin material, does not require a large amount of screed. Very quickly, in just a few minutes, heats up the tile. It consumes one third less electricity than an electric floor heating.


You can, of course, look for flaws in this system. For example, a thin screed can cause cracked tiles. Yes, and it is not cheap. But the infrared warm floor has a lot of advantages that cover these disadvantages..

How to install? Installed under the tiles on a ready-made screed. Do not forget about thermal insulation under the system «Infrared floor heating». The special insulation included in the delivery is spread directly under the foil. The film is cut into strips of a given length along special lines. The film is laid out so that the copper strip is at the bottom, and the contacts are directed to the wall with the thermostat.

We attach the contact clips to the copper strip. Installation wires are connected to them. The places where the wires are connected and the cut of the film must be insulated. Then the temperature sensor is connected and also carefully insulated. It should be noted that the system «Infrared floor heating» accompanied by detailed instructions. Even a teenager will follow it..

How do you lay tiles on a film floor? There is no need to do a screed here. A thin reinforcing mesh with a fine mesh (10-20 mm) is neatly laid on the film. A tile is placed on the grid on a thin mortar. The base of our bathroom is ready. The floor is prepared for front finishing. How to properly tile the floor, and what other options for finishing the bathroom floor are worthy of attention? This will be discussed in one of the next articles in the series. «I want to make a renovation! Bathroom».