Floor with drain: device, installation of a drain

In recent decades, the concept of “good repair” has changed very rapidly. For example, some time ago shower cabins were very popular. Now built-in showers without a pallet are gaining popularity. Their arrangement requires a floor with a drain, and its organization requires the installation of a ladder – a special device for collecting water from the floor. 

Types of drains

Drainage drains are cast according to the type of installation. They are of three types:

• Point. Usually the receiving opening is small, the grating is square, less often rectangular. Installed anywhere.
  

• Linear. The shape of the receiving chamber is rectangular, long and narrow. It is installed mainly along the walls, retreating from them some distance.
  

• Wall ladder. The drain hole is also long and narrow, but this design is different in that it is mounted not only on the floor, but also on the wall. The installation is immured into the wall, in the same place, behind the wall, there are sewer pipes, and the drain hole itself is located exactly near the wall.
  

Most often, to make a floor with a drain, point drains are used, much less often – linear ones. Installation of wall drains is generally a rather rare occurrence, since installation is possible only at the stage of overhaul, not only on the floor, but also on the walls. In addition, such devices are much more expensive.

Gate types

In addition to different design solutions, the floor drain (point or linear) has different types of gates. A shutter is a device that prevents odors from the sewer from entering the room.

The simplest seal is a water seal. In these devices, the discharge pipe has a bend in which water remains. It blocks odors. The disadvantage of such a system is the possibility of drying out. This happens if the water has not been drained for a long time. Also, the cause of drying out can be an incorrect installation (incorrectly selected slope) or the presence of floor heating – the warm floor in the bathroom “dries out” the water in the water seal.

Dry shutters for ladders are more reliable in this regard. They are of several types:

• Membrane. A movable spring-loaded membrane is installed, which, under the pressure of water, falls down, and in its absence blocks the drain hole, blocking the access of gases from the sewer to the room.
  

  

• Membrane made of a material having “molecular memory”. The principle of operation is similar to the membrane, but the reliability is higher – the springs can break, and the material simply striving to return to its original state is more durable.
• Float. This system has a float. In the presence of water, it rises, and when the water has gone, it falls down and blocks the entrance to the sewer.
  

  

• Mint. The drain into the sewer closes the device, which, under the influence of gravity, tends to take a position above the drain.

Dry drains are made mainly of plastic, grates are made of stainless steel or also plastic. There are models with a built-in check valve. It prevents the rise of water when the sewer overflows. When arranging a floor with a drain in an unheated bath, look for models that can be used in cold weather (there are some).

How to raise the floor in the bathroom for the installation of a ladder

The smallest drain ladder, mounted in the floor, has a height of 6-7 cm. At the same time, in order for water to drain normally into it, it is necessary to ensure a slope towards the drain hole of at least 1 cm per meter. This means that by making the floor with a drain, the height of the floor is increased towards the walls. The zero point in this case is the upper part of the installed ladder. How accurately the floor rises depends on the size of the shower or bathtub completely, if you plan to collect water from the entire area of ​​​​the bathroom.

Raising the floor in the bathroom or in the shower can be done in several ways. When choosing a method, it is necessary to take into account the bearing capacity of the floor, otherwise you can harm the entire structure.

Screed of different types

The most obvious way to slope the floor drain in the floor is to pour the screed. But the option is not always the best. Firstly, the usual cement-sand mixture has a lot of weight, and secondly, it “ripens” for a long time. But there are some good options.

• CPS. Ordinary cement-sand screed. The option is understandable, but very heavy – 15-16 kg per 1 sq. meter with a layer thickness of 1 cm. Not every floor can withstand such a load. You need to be especially careful in old houses.
• First pour a layer of expanded clay, pour cement-sand mixture on top (thickness not less than 3 cm). Not a bad option, but it must be considered according to the bearing capacity of the floor – will it withstand or not.
  

  

• Make an insulated floating screed. Plates of extruded polystyrene foam are laid down (not polystyrene, it will collapse under the weight of the screed), pour DSP on top (the minimum thickness is also at least 3 cm). A good option is that the floor will not be so cold, and the total mass is relatively small. An underfloor heating system is easily integrated into this option. More rational – electric, with water a lot of trouble during installation.
• Polystyrene concrete or other types of lightweight concrete. The option is very good, at the same time the problem of the “cold floor” is also solved – since these materials have good thermal insulation properties. Here it will be necessary to look for a compromise solution – between the mass of the screed and the strength characteristics.

The most common way to make a floor with a drain is using a screed. It’s just that the screed can be different, especially since the thickness of the “pie” is usually significant – rarely less than 12 cm – which makes it possible to make it combined. This allows you to provide the required reliability, but reduce weight. Most often, the floor with a drain is made insulated. But the maximum thickness of the insulation and screed is 10 cm, which is clearly not enough to install most ladders. The remaining centimeters are “gained” by laying a rough screed, but it makes sense to make it from lightweight concrete in order to reduce the load on the ceiling.

On the logs

In order not to overload the floors, you can make a podium in the shower or bathroom on the logs. The option is controversial, since high humidity and wood do not mix well, but sometimes this is the only way out. When choosing such a floor drain device, you need to use well-dried wood. Before use, it is treated with protective compounds (according to the instructions, but at least twice). It is desirable to choose from those impregnations that are intended for outdoor work or for direct contact with the ground – their degree of protection is higher. After the composition has dried, you can start working.

• Make it full of wooden joists. Logs are installed in an “envelope” with a center at the location of the drain. In general terms, the technology is as follows: holes are drilled in the floor screed for the installation of studs (M14-M16), the installation step is about 30 cm. Logs are attached to the studs (40 * 60 mm or 45 * 90 cm – from the size of the podium being built). The logs are laid (can be hung up) taking into account the creation of the required slope. On them – moisture-resistant plywood 12 mm or thicker, then GVL, waterproofing, on it – tiles.
  

  

• Make a flat wooden floor on the logs, and lay the tiles with a slope due to different thicknesses of glue. This option is good in small areas – if you do the drain exclusively in a small shower stall.
  

  

The advantages of these methods are the minimum weight, the disadvantages are the complexity of execution, since attention to detail is required, high quality waterproofing.

As you can see, the floor with a drain in the bathroom or in the shower can be done in different ways. Choose the option that best suits your conditions.

Criterias of choice

In addition to choosing a shutter design, it is desirable to choose the mesh size so that it is convenient to lay tiles on the floor: it is desirable that the size of the drain be a multiple of the size of the tile (including mosaics). Pay attention to the material of the body. For a shower cabin in an apartment or house, plastic is quite suitable. These are the most affordable options. More expensive ladders to the floor made of polypropylene, even more expensive – stainless steel.

It is worth choosing the height of the ladder. The minimum value is about 6-7 cm, the maximum is up to 20 cm. Of the technical characteristics, this equipment has only the maximum throughput – how many liters it is able to take per minute. Choose depending on the maximum pressure that your shower can give out: the throughput of the drain should not be less than the maximum amount of water to be dispensed. Both parameters are measured in liters per minute (l/min), so there shouldn’t be any problems.

Floor with drain: work order

Although the designs of the ladders are different, all floor-mounted models are installed according to the same principle – the sequence of work is the same.

It is much more pleasant to stand on a warm floor in the shower, because a floor with a drain is most often done with a layer of thermal insulation. The best thermal insulation material for this is high-density extruded polystyrene foam. It does not absorb water, does not rot, has excellent thermal insulation characteristics, and normally tolerates loads (the weight of the screed and tiles will withstand without problems).

It is more convenient to work with a level (laser level), which has the function of a plane builder. It will make the job much easier.

Preparatory work

First of all, a branch is removed from the sewer riser, where water will flow. The sewer pipe is laid with the required slope (2 cm per 1 meter), the socket is placed at the intended connection point for the drain. After the sewer outlet is installed, they take a ladder, make a preliminary marking – it is necessary to mark the height of the screed on the walls of the shower cabin:

• We install the level so that it marks the axis of the withdrawn sewer pipe.
• We set the ladder so that its axis is about 1,5 cm higher than the axis of the sewer pipe (see photo).
  

  

• After that, we raise the beam of the level to the height of the installation of the grate of the ladder (taking into account the fact that another grate will be installed – add its thickness).
• Since a slope is required for the normal flow of water. It is made 1-2 cm per meter long. From the existing lattice line of the ladder upwards, set aside the required distance.
  

  

• According to the found mark, we set the beam of the level. This will be the level of the screed, which must be maintained along the walls. You can draw this line with a pencil or marker.

Now you can measure the height to which you will need to raise the floor in the shower. In many ways, it depends on the parameters of the ladder (its height). Based on the figure obtained, it will be necessary to plan the layers of the screed and their thickness.

Determining the thickness of the screed layers

Usually they proceed from the fact that polystyrene foam 5 cm thick is laid in the screed. The minimum thickness of the screed is 3 cm (more is possible, less is not). This is in the center near the drain, towards the edges it becomes thicker (the required slope is created). From the existing screed height line, we put the resulting figure down (add the thickness of the polystyrene foam and the screed). At this level, it will be necessary to bring the rough screed.

A rough screed to reduce the load is made of lightweight concrete. It can be foam concrete or expanded clay concrete. Wet work can be minimized. To do this, foam blocks can be laid out at the missing height, fastened with a reinforcing mesh. On top, you can fill the DSP with a layer of 3 cm.

When arranging such a base, a damper tape is needed along the walls. Since in the presence of polystyrene foam or any other insulation, the floor may sag a little, it must be made incoherent with the walls. For this, you need a damper tape. It is exposed around the perimeter of the base. In height, it should be 1-2 cm above all layers.

You can use a special damper tape, you can use thin foam (1 cm thick or less). Even corrugated cardboard will do. The rest of the tape is then cut flush with the screed. She did her job – we got a floating stove.

The poured screed must stand for at least a week – the concrete must gain at least 50% strength. After that, you can continue to work.

Water proofing

To prevent the floor with a drain from leaking, good waterproofing is necessary in the shower. It is better to make it multi-layered. One of the layers can be done at this stage.

Usually coating waterproofing is used. It can be bituminous mastic or special waterproofing for pools. It is applied with a brush in several layers, with an approach to the walls of at least 30 cm. These mastics form an elastic waterproof film on the surface without seams and joints. This type of waterproofing is highly reliable.

Particular attention should be paid to the processing of corners. They can even be glued with a strip of rolled waterproofing (such as Hydroisol, etc.). Apply the first layer of coating waterproofing to the walls, then glue the joint of the wall and floor with rolled waterproofing (put on the same composition), and apply another layer on top.

For those who like to do everything with a margin of safety, the first layer of waterproofing can even be laid under the first corrective screed. All rules remain the same as described above.

Instead of coating waterproofing, you can use rolled. But you still have to lay it on bituminous mastic, well lubricating and pressing the seams. The entrance to the walls is about the same – about 30 cm. If the width of one roll is not enough, the panels are laid with an overlap of 15 cm, they are well coated with mastic.

Choosing a place to install a drain

In order for the tiles on the floor of the shower cabin to look at least normal, it is better to place the drain grate symmetrically with respect to the tile. Therefore, first, on a dry one, we lay out the tiles on the floor (taking into account the seams). When laying out, do not forget to step back a little from the walls – by the thickness of the tile and glue.

Next, we choose the position of the ladder so that everything looks and, at the same time, it was necessary to make a minimum of trimmings. Not only do they take time, they also spoil the view.

Installation of a ladder and insulation

The next stage is the installation of the ladder and the laying of thermal insulation. A ladder is placed in the chosen place, it is connected by a pipe to the sewer outlet (during installation, do not forget about the slope). After that, the insulation boards are laid. It is cut so that it is possible to overlay the installed ladder. A damper tape is also needed around the perimeter. This time it is better to make it also from polystyrene foam, but taking a thickness of less than -2-3 cm is enough. At this level, the Styrofoam will still prevent heat from escaping into the walls.

The joints of polystyrene foam are glued with adhesive tape (so that moisture does not leak out of the concrete). If there are large gaps, they can be tightly clogged with scraps, and then sealed.

Filling the screed

A reinforcing metal mesh is laid on the laid insulation. A ready-made grid of steel wire with a diameter of 3 mm and a pitch of 10 cm is enough. It is cut to size, laid on polystyrene foam. Next, proceed to the installation of beacons.

A floor with a drain must be done with a slope towards the drain. To do this, you need to set the beacons. You can use standard beacons (in a hardware store) or wooden planks. They are installed so that their surface sets the required slope.

When the preparatory work is completed, the ladder bowl is oriented along the walls. You can do this with a square. At the same time, it is necessary to align the measurements as you determined when trying on.

The floor is poured with a drain and an installed ladder with an ordinary cement-sand mortar (for 1 part of cement grade not lower than M400), 3-4 parts of coarse sand. Appropriate additives can be added to make the coating water-repellent.

The poured solution is left to “ripen”. This usually takes 28 days. At the same time, it is necessary to take care of the screed: maintain stable humidity, avoid temperature drops (optimally – around + 20 ° C), direct sunlight. The easiest way is to cover a piece of matting (an old bag) and / or a film. The first 4-5 days the surface should be moistened daily. It is more convenient to do this on matting – there are no traces of drops left. After 28 days, you can complete the finish – lay the tiles.