Methods of waterproofing a floor under a screed. How to waterproof a floor in an apartment - choice of technology and step-by-step instructions for carrying out the work Waterproofing the floor before screeding material

Smooth, beautiful floors are an integral part of modern renovation. To do this, you first need to make a high-quality screed that ensures the smoothness of the coating and, as a preparatory stage, waterproofing the floor underneath it. Waterproofing work can protect buildings from the penetration of water and other liquids, which, over time, can destroy all the previous efforts invested in repairs.

Why waterproof before screeding the floor?

Many people believe that repairs in living rooms without high humidity does not require additional work floor. But the first judgment may be wrong. Waterproofing work is needed absolutely everywhere, and there are several proofs of this:

• Protection against external leaks. In a living space, the bathroom and kitchen are the areas most susceptible to flooding. In this case, the global nature of the process will not affect the final result. And, provided that the apartment is located above the first floor, even an overturned bucket of water can cause discord between neighbors. Another type of external leak is a screed. More precisely, water, which is a significant component of potting mixtures. And which can also leak to people living on the floor below.
• Protection against internal leaks. The humidity level in rooms located close to the ground will definitely be increased. Such buildings include private houses, basements, apartments on the ground floors and garages. Needless to say, concrete is a porous material that is easily saturated with water. And in order to prevent moisture from spreading over the floor and walls, leading to cooling and destruction of them, experts recommend doing double waterproofing - before and after the screed. This is especially true for the construction of private houses.
• Improving the quality of the screed. To ensure that the concrete screed does not crack when it sets quickly, it needs to dry very slowly. Experienced craftsmen They even additionally moisten the coating by covering it with polyethylene. This significantly extends the drying time concrete screed. From a professional point of view, the waterproofing layer will contribute to this process in the best possible way.

Types of insulation

There are several types of materials for waterproofing under floor screed in an apartment. Thanks to them, not only a protective layer is created from water, but also the floor in the room is properly leveled for further repairs.

• Plastering. This insulation consists of several layers with a total thickness of up to 2 mm and is used in two types - cold or hot. It can be used well in brick and concrete buildings, but is completely unsuitable for wooden floors.
• Painting room. This coating is applied with a wide brush to painting work until a thickness of 2 mm is reached. Materials for coating can be bitumen mastics, as well as polymer paints and varnishes. Painted insulation also comes in two types - hot and cold. Cold look considered the most convenient due to the ease of application and high efficiency, as a result of the use of an epoxy-rubber mixture. With the hot method, you have to melt the bitumen, which is not always possible in a closed space.
• Pasting. The essence of such insulation is to secure waterproof materials to the floor. roll coverings, for example, roofing felt, isospan, technonikol, etc. Rolled strips are laid in several layers with a slight overlap. To fasten them, use mastic or a gas burner. The latter is used by specialists in the fused method. This insulation is universal and can be used in both concrete houses, and in wooden ones.
• Impregnating. It consists of a porous material that is pre-impregnated with astringent moisture-resistant mixtures. These can be polymer varnishes, bitumen resins, and petrolatum. The use of such insulation is recommended by professionals for wooden houses. In this case, it is advisable to impregnate not only the floor, but also wooden poles with all existing ceilings.
• Cast. According to experienced builders, this method is considered the most durable and reliable. For protective coating resort to a mixture of hot asphalt and bitumen mastic. It is poured in 2-3 layers to a thickness of 10-25 mm. Naturally, this greatly affects the cost of insulation and its weight. Therefore, in order to avoid unforeseen consequences, it is necessary to make all calculations with special care.
• Backfill. Here the name speaks for itself - this is insulation, which consists of bulk materials with increased moisture resistance. For reliability, bicarbonate powder and asphalt insulation must be covered in a thick layer - at least 50 cm, which, compared to other methods, is unrealistically large. However, such a thick pillow has an undeniable advantage - good additional thermal insulation, which is most often used either in the basement or on the ground floor, where the cold is felt most strongly.
• Mountable. The components of such insulation can be different - from profile tapes to plastic or metal plates. They are attached to the floor using special mounting ties.
• Injection. This is one of the best modern and high-tech solutions that creates protection against water by filling all microcracks with liquid material. Thanks to a special formula, the mixture penetrates into concrete and hardens in the form of crystalline formations. At the same time, the integrity of the structure is completely preserved and, moreover, withstands the penetration of moisture under pressure. This insulation also increases the resistance of the floor to aggressive chemicals.

Waterproofing materials

Technologies for waterproofing the floor in an apartment before screeding

Depending on the type of material, the technology of waterproofing work will vary greatly. Below are the most common methods of such processes.

Gravel-sand cushion

• Preparatory stage. Before starting construction on the site, it is necessary to remove fertile soil with organic impurities and level the soil itself.
• On the leveled ground, over the entire area of ​​the future floor, crushed stone should be poured, the size of the fraction should be no more than 50 mm. Next, the crushed stone must be compacted and leveled to avoid height differences. Depending on the location of the groundwater, different layer heights are needed - from 0.2 m to 0.5 m.
• The next layer will be coarse sand. It must be covered with a surface 0.1 - 0.4 m thick, and then watered well. After moistening the sand, it should be thoroughly compacted with a hand roller.
• It is necessary to place strips of geotextile on top of the gravel-sand cushion and glue them together with a construction hairdryer. This material is resistant to fungi, mold, rodents, rotting and chemical exposure without releasing toxic substances. It perfectly allows water and moisture to pass through, but prevents the layers from mixing, preventing the passage of larger particles such as sand, gravel, etc. Geotextiles are needed as a shock absorber and to protect the insulation from damage.
• The next step is to lay foam insulation, for example, penoplex or polystyrene.
• After completing all of the above work, you can carry out waterproofing with roll materials or immediately begin screeding on an already prepared area.

Important! Foam insulation cannot be used due to its instability to mechanical damage.

Waterproofing floors with roll materials

There are two types of insulation in rolls - built-up insulation, when special gas burners are used during installation to melt bitumen, and adhesive insulation, a roll of which is fixed to the base.

Roll insulation technology is as follows:

• First, along the perimeter of the walls you need to lay damper tape, which is foamed polyethylene. It is needed in order to avoid cracks in the joints between the floor and the wall. This is due to the fact that temperature fluctuations affect the floor area - it can expand and, accordingly, narrow, leaving behind huge gaps. To attach the damper tape, you can use dowel nails or glue.
• The next step will be leveling the floor area. Sometimes there are potholes in the floor that need to be filled with sand or sealed with cement-sand mortar.
• Roll insulation is laid on the floor in strips with a slight overlap of at least 10 cm, and with “climbing” onto the walls - 15 cm. Roofing felt must be glued to the floor with bitumen mastic, which is also used to glue the joints (overlapping).
• When using built-up materials, for example, glass insulation, they are attached to the base of the building floor gas burner. And overlapping polymer films can be easily welded with a construction hairdryer.
• Waterproofing materials in a roll are laid differently. Roofing felt needs at least a double layer, while polymer materials with fused films require a single layer. After waterproofing work is completed, the floor is reinforced and screeded. And the final step will be to trim off the excess pieces of insulation flush with the floor.

Important! Treatment with a primer (primer) is only necessary when using roofing felt, but when using polymer waterproofing films you can do without it.

Coating waterproofing

• First you need to remove the garbage, various pollution and dust from the concrete base. Particular attention should be paid to ensuring that there are no sharp objects, cutting protrusions and chemical stains, for example, from oils, solvents and other active substances, which, upon contact with the coating waterproofing mixture, will destroy its properties.
• For this waterproofing, it is best to use bitumen-rubber mastics with a cold application technique. First, you need to go over the entire surface with a primer (primer) suitable for the mastic used. It would be ideal to combine materials from the same manufacturer to guarantee the best result.
• Primer must be applied paint brush in one layer, while carefully covering all inconspicuous areas. Its action will reduce the amount of dust and improve uniform adhesion of the mastic to the floor. Particular attention should be paid to treating areas near pipes and at the joints with the wall. The drying time for the primer usually ranges from 2 to 5 hours. However, in a cold room, a different time for complete drying is possible.
• Applying mastic requires certain rules. It should be applied in several layers only after the previous one has dried and each time changing the direction of the roller. Again, hard to reach places near the batteries, treat with a thin brush with special care.
• Complete drying of the coating waterproofing usually takes about two days. After this, you can begin to perform the screed. When laying reinforcement, it is necessary to use plastic guides to avoid contact metal structures with coating waterproofing - under load they can damage it.

Important! To reliably waterproof a floor, you can use several methods at once.

Features of waterproofing under heated floors

There are no special restrictions when waterproofing underfloor heating. The material can be laid both on top of the cable and under it. This is explained by the fact that manufacturers expect the cable to operate under various conditions, incl. and on the aquatic environment. The only condition is that the cable must not be placed in direct contact with the waterproofing. To separate these layers, you need to use a metal mesh or a dividing screed.

When under the tile, the insulation itself lies above the cable. Therefore, experienced specialists strongly recommend filling the cable with cement-sand screed.

At bitumen waterproofing When using torches, exposed parts of the cable must be protected from flame and high temperature special materials.

Concrete is not afraid of high humidity. Moreover, being constantly in water or in a moistened state, concrete stone becomes stronger and stronger. And what usually needs to be protected is not the concrete itself, but ours or our neighbors’ property below, which does not need moisture at all. So waterproofing the floor under the screed is a matter of safety of property and our everyday comfort.

The problem of waterproofing a concrete floor can be solved in different ways. The point is that there is different types waterproofing materials. None of them are perfect, but correct use, all perform their task - protect against water penetration. But some are effective against moisture in its liquid state, while others cut off vapors. After all, concrete can also become wet due to evaporation or capillary suction. So to choose a material for waterproofing, you need to have a clear understanding of the ways in which moisture appears and in what form it can come. It is also worth thinking about where and how moisture will go if it does get into the concrete. The tasks are different, but waterproofing the floor under the screed must solve all of them at once, otherwise there will be problems.

What are the types of waterproofing materials?

It makes sense to separate all formulations according to the method of application. Often this factor is decisive.

Coating

They have a semi-liquid or liquid consistency. They are applied to the base with a brush, but can be in the form of a plaster mixture. Actually, the plaster we are used to is also a type of waterproofing of walls.

The easiest class of waterproofing materials to apply. Before drying, the compositions have sufficient fluidity or elasticity so that they can be applied to uneven grounds. They fill in irregularities, even quite deep ones. And this is their advantage. But under loads or mechanical stress they collapse. If coating waterproofing is used in a floor structure, you must walk on the surface carefully.

Pasted or laid

This is the oldest and perhaps most popular method of applying waterproofing. Back in Soviet times, roofing felt was used to protect against moisture. It still exists, and there is a whole list of others that have some additional properties. Modern roofing felt, by the way, although cheap, is too thin and unreliable. It is hardly suitable for high-quality waterproofing. If possible, take something more durable.

Waterproofing under floor screed in an apartment is usually done with film. Adherents of old technologies use roofing felt. At correct installation(with overlapping and double taping of joints) both materials fulfill their purpose. But only they should remain intact. And you will have to walk along them, setting up beacons, laying out and leveling the solution.

Penetrating waterproofing

There are two types. The first is applied to the surface of the concrete, the second is injected deep into the cement stone. The second type is usually used to repair the foundation, and the first is what we need. It is applied with a brush to vertical or horizontal surfaces.

Penetrating waterproofing is made on the basis of high quality Portland cement. Finely ground sand and special chemicals are added to it. Sold in powder form or ready-to-use formulation. Apply to the surface with a brush.

After application, the composition penetrates deep into the concrete. To what depth depends on the specific composition. There are those that can leak even half a meter. But this is not required for the screed. After application, the chemistry reacts with the components of concrete and forms insoluble compounds. These compounds clog the pores of concrete and “heal” even large cracks. This prevents the entry of moisture.

Penetrating waterproofing is usually used when there are problems

Penetrating waterproofing is available for concrete in various conditions. Available for application to concrete stones with cracks of varying depths/widths. The cracks are closed by insoluble crystals. Such compositions are suitable for restoring the waterproofing of screeds with cracks up to 3 mm (reservoir). There is one for application on fairly durable concrete without cracks, and there is one for loose crumbling bases. There are those that remain elastic and “healed” cracks do not let water through even when enlarged. When selecting, carefully read what substrates they can be applied to and what they can do.

A convenient thing, high-quality and long-term moisture cutting, easy to use (those that are applied to the surface with a brush). But it's expensive. And it is usually used when there are problems. It is not used during construction or ordinary renovations in an apartment - it is impractical. All problems can be solved by other, cheaper means.

Water repellents

Water repellents are substances that make concrete resistant to water. The water just sits in drops or puddles and doesn’t seep inside. There can be two types - an additive during mixing or a solution that is applied to the concrete. The second type may seem similar to penetrating waterproofing, but their mechanism of action is different.

The additive makes concrete impervious to moisture throughout its entire depth. The absorbed solution forms a layer (to a depth of no more than 5 mm) that does not allow water to pass through. As you can see, both types solve the problem of moisture protection. But the first one can be used only at the manufacturing stage, while the second one can be used after the strength has been gained (not earlier).

If you treat the fabric with a hydrophobic compound, it will also become waterproofing

Sometimes it’s easier to lay waterproof concrete right away than to create barriers later. But the cost of hydrophobic additives is high and this is their only drawback. And water repellents that are applied to the surface are washed out over time, which leads to a deterioration in waterproofing characteristics.

In general, these are all types of waterproofing. There is plenty to choose from, but that’s not to say that the choice will be easy. As usual, it’s either simple and reliable, but expensive, or cheap, but complicated and reliability is in question.

Waterproofing the floor before screed: when, why, with what and how

Waterproofing materials are laid under a concrete screed in two cases:

• V multi-storey buildings so as not to flood the neighbors below;
• in private houses, when they make a finishing screed over concrete preparation, cutting off moisture from the finishing screed and the coating that will be laid on it.

First, let's talk about how to waterproof a room under a screed. Modern coatings require a level base, so repairs rarely do without this step.

Waterproofing is laid on the floor slab in the apartment, and screed can be poured/laid on top

Waterproofing materials under screed in living rooms

In living rooms, the appearance of water is not very likely. Unless there is a flood due to burst heating pipes or something similar. Therefore, in such rooms, flooring materials are most often used - film or roll waterproofing. They do their job well and are inexpensive. The rules for laying film and roll waterproofing are the same.

• Waterproofing sheets are laid so that their edges overlap each other by 10-20 cm. These edges are glued double-sided tape. It is safer to glue the joints twice, securing both edges.
• The waterproofing is spread over the walls. The edges are fixed to the walls slightly above the level of the future finishing coating. It is easiest/best to secure with strips with nails or self-tapping screws. Then it rolls out around the perimeter of the room.

Film or roll waterproofing are the most economical options for installation under screed

In the place where the film or roll material extends onto the walls, make a small fold. If this is not done, the material here is often stretched, so it is easy to tear.

One important point— the film should be thick and dense. Density - no less than 200 g/m². It comes with a sleeve, double. Like this, without cutting it, they place it under the screed. Then, when you walk on it, try not to tear it. Therefore, before laying, sweep and remove all rubbish. Even a small pebble or sliver can tear your waterproofing material.

Yes, film is the most cheap look waterproofing floor screeds. And it performs its functions perfectly. But if the screed is reinforced or you are laying heated floor pipes, the likelihood that the film will not break is extremely small. Even if you walk in felt slippers. For such cases, it is better to use more expensive, but more reliable and durable materials. For example, coating.

For bathrooms and kitchens

The likelihood of water appearing in the bathroom, toilet or kitchen is much higher. Therefore, they are trying to make it more reliable under the screed. To achieve this, risk areas are additionally protected. Weak spots in the floors of high-rise buildings are the joints between the floor and the walls, as well as the inputs/outputs of heating pipes, water supply, and other communications that are introduced through the floor. This is where additional protection comes in.

The easiest way is to seal all visible cracks with a solution (cement + 3 parts of sand), and then coat the corners and places where communications enter with coating waterproofing. This is usually latex paint, but can be any mastic with suitable properties. But it’s better not to use bitumen indoors.

The most vulnerable places are covered with a double layer of waterproofing
Which waterproofing is best for floors? Whole and without holes

After drying, you can roll out the damper tape and pour or lay the solution. Please note that such a screed will still be floating. It has no connection with the base, even though the rubber film is very thin.

Waterproofing a floor under a concrete screed

In recent years, private houses have increasingly been made not of concrete, but of concrete. Any type of coating can be laid on this base, although the costs are several times higher. To make the screed insulated and securely cut off groundwater, first make concrete preparation (rough concrete floor). This is unreinforced (usually) concrete slab or compacted crushed stone poured with lean concrete. This plate is needed so that high-quality waterproofing can be made.

Laying a concrete floor in a private house on the ground: with waterproofing and insulation

Waterproofing a floor under a screed in a private house is no different in this case. You can spread film or rolled materials. You can use roofing felt, but it’s better to at least use “Gidroizol” or, preferably, something denser and more durable. Just imagine that if the floor gets wet, you will have to break everything down and redo it. This is a colossal investment in time and money. There will also be an option with penetrating waterproofing and the use of all sorts of “treatments”. But their cost...

In any case, when laying rolled materials or film, the edges of the material should be placed slightly higher than the waterproofing layer in the foundation. This is important. This way you cut off moisture that may come from the foundation.

Do I need waterproofing over the screed?

When installing floors in “wet” areas or rooms, people sometimes wonder: can double waterproofing be done? Place one under the screed, the other on top. If you don’t know whether there is waterproofing in the existing screed, it is quite flat and you are not going to redo it, but will be laying an expensive or non-removable coating, then this option seems logical.

Sometimes it is also necessary to install waterproofing after screeding.

The second option is if you are very tormented by the fear of flooding your neighbors below. For your own peace of mind, you can lay a second layer on top of the screed. There is no need for this, but there is nothing you can do for your own peace of mind.

In the apartment

If the floor is tiled, one (high-quality) layer of waterproofing under the screed is sufficient. Firstly, tile is a waterproofing material. Yes, seams sealed with cement-based grout allow water to pass through. But polymer grout is waterproof. If you are so afraid of a flood, it is better to use good grout. Here you will have double waterproofing.

When can waterproofing be laid on a screed? If in the same kitchen or in the hallway. To calm your paranoia, spread the film over the screed, then the backing under the laminate, and then follow the technology. Such a thin additional layer will not affect anything.

Cracks in the screed can be repaired and covered with waterproofing

When else do you need waterproofing on a screed? If the screed is old, there are cracks. In general, in an amicable way, if there are a large number of cracks, you need to remove the old screed and pour a new one. But if there are only a few cracks and the screed pieces are at the same level, you can try to restore the slab under the tiles. To do this, widen the cracks and fill them with a repair compound. Then, if you are laying tiles, you can coat it with coating or penetrating compounds. For other types of coatings, such more serious waterproofing is also desirable, but you can get by with film.

In a private house

The same approach - with laying a second layer of waterproofing on a screed under a laminate or carpet - can be justified in a private home. But here it is needed not in order to protect the “neighbors below”, but in order to cut off the flow of water from the ground. But if there is such a problem, then this is only a temporary solution. Dampness will accumulate under the film and you will still have to redo everything.

In a private house, concrete floors on the ground must be protected from capillary entry of moisture

What exactly needs to be done must be decided by examining the floor, foundation and surrounding area. But the first thing you can try is penetrating waterproofing. If the problem is that the bottom layer has torn and stopped working, this will work. If the problem is foundation settlement or cracks, then you need to look at the degree of damage and then make a decision. In general, in such cases you can’t get by with a little bloodshed.

If you decide to implement major renovation apartments, then you need to start with the arrangement of the floors. If you need to install new flooring, then before this you definitely need to make a screed. However, you should prepare for this work. That is, waterproofing must be carried out before screeding the floor in the apartment. You will learn further how and how to do this.

Why is the procedure needed?

The presented process must be carried out without fail. Such protection will ensure long-term and efficient use of the premises. That is, if you have problems with the water supply or tap and water flows directly onto the floors, you will have the opportunity to avoid conflicts with neighbors whom you will flood. Without insulation, liquid will seep through even the strongest layer of concrete.

Please note that waterproofing before screeding the floor in an apartment should be carried out in all rooms, and not just in the kitchen and bathroom. The fact is that the concrete solution with which you will level the surface also contains a large amount of moisture. If the liquid evaporates gradually, which provides water protection, the screed will be stronger and of higher quality.

Thanks to this procedure, you will be able to protect the room from excess moisture, the spread of fungus and mold.

Coating features

Waterproofing before screeding the floor in an apartment has certain nuances:

1. If your home is located on the ground floor and there is no basement under it, then the protection should be of the highest quality. The fact is that ground moisture contributes to the rapid destruction of concrete.
2. Before insulation, the floor surface can be leveled using a special mixture.
3. If there is a redevelopment of the premises, which can be carried out with the demolition of partitions or walls, then only after this a protective layer is laid.
4. It is best to completely waterproof the floor. A partial one will not give the desired effect, and the water will still find somewhere to leak.
5. If there is a high level of humidity in the room, then you need to protect not only the floor, but also the walls.

Types of insulation

Before waterproofing is carried out before screeding the floor in the apartment, you need to figure out what exactly should be applied. There are these types of materials:

1. Rolled. Most often, roofing felt or fiberglass is used in this case.

2. Membrane. Most often this material is polyethylene. It is inexpensive, but cannot be called durable, as it breaks quickly.

3. Liquid bitumen solution with additives. It has a fairly high cost, but is very easy to install. Moreover, after drying, it forms a very durable layer that does not allow liquid to pass through.

4. Plastering. Such mixtures consist of cement and various kinds additives Naturally, such a substance will need to be diluted with water and applied with a spatula.

In addition, waterproofing the floor in an apartment before screed can be applied in the following ways:

• spreading;
• spraying;
• pouring;
• smearing;
• gluing.

Preparation for waterproofing

Now you need to figure out what needs to be done before implementing such water protection. Preparatory work will include the following:

1. Complete cleaning of the room from debris and dust. The room should be completely empty.
2. Leveling the surface using special repair mixtures.
3. Preparing tools and materials for work. For example, if you decide to use roller barriers in cold weather, then you need to bring them into the room for a while to warm up. Only then can you start working.

Features of roll protection

So, let's take a closer look at the procedure. Waterproofing before screeding (you already know the materials used in the work) should be done in stages. If you decide to use rolled materials, then the procedure for laying them has the following features:

1. First you need to spread the covering on the floor. For maximum protection, it is better to use a couple of layers. Please note that at the junction of horizontal and vertical planes, the canvas should extend onto the wall another 15 cm from the floor.

2. Please note that such protection must be continuous. If you have to use several pieces of material, then it needs to be overlapped, and it should be 20-30 cm.

3. The product must be carefully folded in the corners.

4. In order for such protection to be effective, it is better to coat the joints between layers of material

How to make coating insulation?

If more serious protection is required, it is better to use mastic. In this case, you can safely skip the stage of leveling the surface. Any special equipment or additional tools you won't need it. Waterproofing the floor in an apartment before screeding (you can see a photo of the process in the article), therefore, involves the use of dry substances, the preparation of which requires water. In addition, you can use ready-made liquid formulations.

Naturally, before starting work, the floor must be thoroughly cleaned and covered with a layer of primer. Next special tape you need to glue the corners and joints where the likelihood of moisture seeping is highest. Next, you should prepare a solution.

It should be applied very carefully to the floor and walls, in the case of the latter - to a height of about 35 cm. For this, use either a roller or a brush. There is no need to rub the composition hard into the floor or smear it. After the first layer has set, it must be moistened and a second one applied. Moreover, they must be laid perpendicular to each other. It is enough to apply only three layers.

If the floor in the apartment before the screed ("Gidroizol", for example) is successful, you can fill it with prepared concrete.

How to insulate a wet screed?

As you can see, waterproofing the floor in an apartment before screeding with your own hands is quite simple. You just need to get the hang of it. Many readers are interested in how to make waterproofing when wet. It’s very simple.

1. Clean the surface and then apply a primer solution to it.

2. After it dries, you need to find and seal all cracks and holes with a sand-cement mixture.

3. Now you can start applying it to the floor using a trowel. Maintain the same layer thickness over the entire area. After it dries, apply at least 3 layers of mastic. For this waterproofing to dry completely you will need at least 6 hours.

Please note that this method may only be suitable for those rooms that have normal or low humidity levels.

Some nuances

Regardless of which material you choose for work, each process has its own subtleties that should be taken into account:

1. For good adhesion, each layer of mastic must be applied no later than after 3 hours.
2. If you decide to use rolled materials, then you can choose adhesive-based products. This will greatly simplify and speed up the installation process.
3. Polyethylene or polypropylene barriers are most often used if they will serve as a base for a wooden floor.
4. Mastic is the most commonly used material, which allows not only to protect the room from moisture, but also to partially level the surface being treated.
5. The peculiarity of liquid insulation is that after drying it turns into a thin but reliable protective film. Its thickness should not exceed 3 mm. The presented material is applied with a brush, but such protection will have to be renewed every 5 years.
6. If you decide to choose the method of fusing the composition onto the floor, then you will have to purchase a gas burner. Naturally, this method is quite labor-intensive and even fire hazardous.

As you have seen, waterproofing the floor before screeding (the materials have also already been considered) is done quite quickly and simply. You can cope with this task without the involvement of specialists.

From this article you will learn:

• What are the main types of waterproofing
• What materials will be required for this?
• How to waterproof a floor under a screed using rolls and plaster
• How much does it cost to waterproof a floor under a screed from professionals?

The comfort of living in a private house in Moscow is largely determined by how well its renovation is done. This process includes several steps, each of which requires certain financial investments, time and strict adherence to the technology for performing the work. The list of the most important activities includes floor repair. In this article we will tell you how to waterproof a floor under a screed.

What does it mean to waterproof a floor under a screed?

To understand the issues of arranging waterproofing for a subfloor, you need to understand exactly what function the screed performs and what requirements are imposed on its installation. Let's start with the definition of the concept of “screed”. This term is used to designate a durable layer, which is the base for laying the finishing coating on the floor surface. One of the functions of the screed is to provide a level base for subsequent installation facing material. This will allow for a perfectly even installation. decorative covering for finishing the floor, and will also prevent its deformation and rapid destruction.

There are several options for floor screeds.

• Concrete (cement) screeds classified as wet types of flooring. This option is most often used in the process of renovating houses and apartments. The construction of concrete screeds is carried out by pouring a rough base with a composition that includes water and a certain brand of cement. In addition, polymer components can be added to the cement screed.

• Self-levelingcompositions also referred to as wet screeds. In this case, the base is filled with special building mixtures, which are evenly distributed over the rough surface. This property of the material greatly simplifies the arrangement of screeds with a high-quality and smooth surface.

• For dry screeds Only bulk materials are used. To make it, gypsum fiber is used, which is laid on logs. Dry floor screed (waterproofing of such a layer will be discussed later) is the fastest option for leveling floors.

Wet types of screeds take almost 30 days to dry. The base for the floor must be thoroughly dry, and only then can you proceed to finishing. The range of companies involved in the sale of building materials also includes quick-drying compounds that significantly reduce the time required to complete the work. But even such mixtures do not allow you to equip the base of the floor in one day. In addition, manufacturers indicate that dry screeds should not be used in rooms with high humidity levels.

Arrangement of the base for the floor - necessary stage renovation of an apartment or private house, regardless of the chosen flooring option. Floor screed using waterproofing and beacons is necessary both before further painting of the floor and before laying expensive parquet.

The quality of the screed is largely determined proper protection from moisture. Waterproofing the floor before or after screed is an important stage in its repair. It provides protection against moisture penetration from the outside, and also prevents flooding of other rooms. In addition, the waterproofing layer protects the floor screed itself from high humidity, which is especially important for basements and rooms located above them. The fact is that a concrete base in damp conditions quickly collapses and loses its strength and performance qualities.

The protective layer should be especially reliable in places where there is an increased risk of water leakage. For example, waterproofing the floor in the garage before the screed, in the kitchen, in the bathroom, etc.

If a room is accidentally flooded without a protective layer under the screed, moisture will quickly seep down through the pores and microcracks. If this room is in an apartment multi-storey building, then as a result the repairs of the neighbors below will be seriously affected. To the places increased danger from the point of view of water flow, these include the joints between the floor surface and the wall.

Waterproofing the floor screed solves another important problem in protecting the health of the occupants of the house. The fact is that moisture collecting in the concrete base creates a favorable environment for the development of fungi and mold, which can provoke various diseases.

Waterproofing the floor under the screed in the house is a necessary condition for subsequent high-quality styling floors Cement composition, which is applied to the protective layer, will receive higher strength. In addition, leveling its surface will be much easier. The role of waterproofing the base floor is especially important in those houses where there is no basement. Such buildings especially suffer from moisture, which comes from the soil through micropores.

Waterproofing floor screeds under tiles is necessary not only in the bathroom or kitchen. This operation must be carried out in all premises. The point is that the pipes heating system pass through all rooms and there is always a risk of leakage. Such an accident can have serious consequences if there is no proper moisture protection installed on the subfloor.

The cost of waterproofing materials is quite affordable, so installing a system that can protect the floor from excess moisture will not lead to a significant increase in the cost of repairs. Possible damage from flood, dampness and fungus will be much greater.

Main types of waterproofing

The procedure for arranging waterproofing of a screed consists of forming a water barrier. For this purpose, special materials are used that do not allow water to pass through. First of all, it is necessary to apply a waterproofing layer in those places where there is an increased likelihood of moisture penetration through the subfloor (wet areas). Various means can be used for this:

1. Pasted waterproofing involves the application of sheet or roll materials on a synthetic or cardboard base, impregnated with a bitumen composition. To ensure the elasticity of such materials, they are heated. Then the adhesive waterproofing is fused onto the prepared floor surface. It is very inconvenient to work with such materials in bathrooms or bathrooms. To heat them, a gas burner is used, which cannot be used in cramped, poorly ventilated rooms. In addition, working with adhesive waterproofing requires appropriate experience and skills.
2. Painting waterproofing produced using mastic based on bitumen or polymers. These materials penetrate the pores of concrete and, by clogging them, close the paths for moisture penetration. Painting waterproofing is applied in several layers with each of them thoroughly dried. It should be noted that bitumen materials have a specific pungent odor, and polymer-based mastic is considered a more environmentally friendly and safe option for waterproofing. The drying time of high-quality waterproofing mastics is one day.
3. Coating waterproofing– polymer compositions, including fine quartz sand, plasticizers and cement. Such materials are applied to a prepared and cleaned surface in the same way as plasters. The application process involves coating the floor surface using a trowel and spatula. The material is applied in several layers, drying each of them for six to eight hours.
4. Cast waterproofing applied by pouring hydrophobic materials onto the floor surface. For this they can be used different compositions. Depending on the material, this protective agent is applied cold or hot.
5. Impregnating (penetrating) waterproofing involves applying a water-repellent impregnation for concrete, which fills pores and microcracks to a depth of 15 to 18 cm. In addition to the main function of protecting against moisture, waterproofing penetrating materials prevent further appearance of cracks and efflorescence on the concrete surface.

A correctly applied waterproofing layer should form a sealed hydrotrough over the entire floor area extending onto the wall to a height of about 200–300 mm.

Materials for waterproofing floors under screed

Coating compounds

Coating materials for moisture protection can be produced on various bases. Depending on the components used, the following types of compositions are distinguished:

• acrylic-based water-based;
• bitumen-rubber;
• bitumen-polymer;
• cement-polymer;
• polyurethane;
• bituminous.

Materials for waterproofing bitumen-based floor screeds are available with various fillers, as well as with the addition of organic solvents. Fillers give mastics elasticity. Plasticizers, latex, and crumb rubber are used as such additives.

Mastic compositions have a high level of adhesion. They are used for concrete and wooden surfaces.

Coating waterproofing agents based on bitumen have a number of disadvantages:

1. after application, the mastic may crack, and chips may appear on the surface due to temperature changes;
2. biological corrosion;
3. pungent odor during work on applying a protective layer.

Despite the disadvantages of coating waterproofing listed here, it is this type of material that is used to perform work in the bathroom (this is the most affordable way protect the screed from moisture penetration).

The price of materials of this type is affordable for the consumer, but they do not last more than 5-6 years.

Mastics that are produced on the basis of polymers have almost no negative qualities, therefore they can be used on different objects without restrictions.

Experts attribute the advantages of coating agents to the ease of application of the material using paint brush on the surface under the base of the floor, on the lower part of the walls, as well as on corners and joints.

Plaster mixtures

Plaster waterproofing mixtures can also be classified as coating types of protective materials. But they should be separated into a separate group, as they differ in their composition.

Produce plaster mixtures from components such as gypsum, cement and polymer components. As noted above, bitumen-based coating materials begin to lose elasticity at temperatures below 0 °C. They become brittle, and cracks may form on the surface of the waterproofing layer. Plaster compositions are not afraid of even strong temperature changes.

The catalogs of companies selling waterproofing materials present a wide selection of mixtures for protecting floor screeds from moisture using plaster. The most popular products in this area are the products of the Knauf and Ceresit brands.

For example, in the composition waterproofing mixture KNAUF FLACHENDICHT contains artificial latex, which gives high elasticity to the protective layer of the screed. This material, after polymerization is complete, is capable of maintaining performance characteristics in the temperature range from -18°C to +55°C. The FLACHENDICHT mixture can be immediately applied to the surface to be treated without preheating.

Another example of high quality plastering hydro insulating material– compositions of the Ceresit CR-65 brand. These mixtures are characterized by improved adhesion to concrete surfaces (provided that such a surface has been pre-treated with a primer). Waterproofing Ceresit CR-65 is one of the most popular waterproofing materials on the domestic market.

Rollers or brushes are used to apply a protective plaster layer under the floor screed. If there are joints on the surface to be treated, they must be sealed using sealing tape. Experts note that for waterproofing and arranging floor screeds, it is better to select materials from the same brand, which are perfectly adapted to each other.

Materials for adhesive waterproofing

The most popular materials for adhesive waterproofing of floor screeds are: roofing felt, isoplast, ecoflex, iselast, mostoplast, uniflex, hydroisol.

All of them are resistant to temperature changes. Provided the installation technology is followed, lining materials can provide reliable protection floor screeds from moisture.

These materials are available in the form of rolls or sheets. For their production, components are used that provide high degree waterproof and elastic. At the same time, using such materials it is quite difficult to waterproof the floor screed in difficult places, for example, in the corners of the room.

Manufacturers produce 2 types of adhesive waterproofing materials. The first type is applied to a special adhesive composition(bitumen mastic), and the second refers to self-adhesive materials. On the back side, sheets of the second type have a mastic layer covered with a protective film, which is removed before installing the waterproofing layer.

Until recently, the most famous type of lining materials was ordinary roofing felt. With the advent of more modern means it began to be used much less frequently. Various types adhesive waterproofing can be produced both on a polymer and bitumen basis, therefore they have different characteristics. This point must be taken into account when choosing the type of protection.

Polymer material Available in the form of film or membranes made of vulcanized rubber. Most types of such products have an applied adhesive composition, so they are easy to install.

Polymer waterproofing floor screeds are different:

• small layer thickness;
• long term operation;
• high mechanical strength;
• no shrinkage;
• resistance to vibrations.

Pasting waterproofing materials bitumen based have become more widespread due to their affordable cost. Let's take waterproofing as an example. It is made from fiberglass with bitumen impregnation. To give this material elasticity and resistance to mechanical deformation, special plasticizers are used. Hydroisol is resistant to fungi and biological decomposition. On the building materials market it is presented in single-sided or double-sided versions.

Double-sided waterproofing can be distinguished by the presence of a protective film coating on both sides. During installation, this material melts under the influence of high temperature. This type is used exclusively when it is necessary to equip multi-layer waterproofing protection.

One-sided waterproofing has a protective film on one side, and a layer of mineral chips on the other. Its main purpose is to provide roof waterproofing. Single-layer adhesive material can be used as an outer covering for soft roof. With its help, you can protect both concrete and wooden bases from moisture. This material is laid on the surface of the wood using bitumen mastic without melting.

Materials for cast waterproofing

Various components can be used to produce cast waterproofing compounds. The method of constructing a protective layer using such materials is indicated in their name. Waterproofing work involves pouring a cold or heated product.

Hot waterproofing In the domestic building materials market it is represented by asphalt and polymer-asphalt materials. These include asphalt concrete, pitch and hot bitumen. This protective layer for floor screed has a high resistance to deformation, and is also durable, elastic and has a long service life.

Before applying the material, it is necessary to seal the existing seams (for this you will need mastics and sealants). Hot waterproofing compounds are more often used for work in private houses, rather than in apartments.

To cold types of waterproofing include several known materials, which are often called “liquid rubber” or “liquid glass”. They may have different compositions, but do not differ in application technology.

Book a discount on repairs
up to 10% for 15 days!

Enter your number and we will book
personal discount for you

Liquid rubber is produced on a bitumen base with polymer fillers, which give the waterproofing layer higher performance qualities.

The fixative for the emulsion of such components is CaCl₂ (calcium chloride), which helps reduce the density of the mixture to levels at which it is possible to apply waterproofing to the floor screed by spraying. Before adding calcium chloride to the emulsion, it is diluted with water in a ratio of 1:10.

To ensure the reliability of the protective layer, it is necessary to strictly adhere to the technology. Need to provide preliminary preparation floor base and perform work at air temperatures above +5 °C.

On sale you can find liquid rubber in the form of emulsions with different consistencies. This allows you to select a material with a different application technology:

• Pouring installation method- the most common option, in which you can do without the use of expensive equipment and efficiently fill even small cracks in the coating, ensuring a flat and smooth surface.
• Sputtering– characterized by a higher technological efficiency of the process of applying a waterproofing layer. Professional skills and equipment are required to perform the work. Compliance with the requirements of spraying technology allows you to create a high-quality protective layer on the floor screed. In this case, the waterproofing composition is supplied under pressure, which helps fill not only microcracks, but also the smallest pores.
• Painting (coating) technology- the easiest way to apply waterproofing material under the subfloor. Materials of this type are sold in the form of solutions or pastes, which are distributed over the surface to be treated using a brush.

Liquid rubber, after being applied to the base of the floor, forms a dense elastic film that provides a high degree of protection against moisture penetration.

Different types of liquid rubber may differ in their operational properties, but their general characteristic is environmental cleanliness. These materials do not emit substances harmful to human health either during application or during further use.

The advantages of all types of compounds from the liquid rubber category include:

• high adhesion rates to surfaces made of different materials;
• resistance to chemically active substances;
• no need for additional preparation of the treated surface;
• formation of a continuous protective layer without seams;
• high flexibility, resistance to deformation and strength of the waterproofing layer.

Liquid glass can also be applied to the surface of the subfloor using a cold method. This type of cast waterproofing is similar in consistency to the liquid rubber discussed above, but differs in composition. To produce this material, potassium-sodium silicates (K2SiO3), soda and quartz sand are used.

Excellent performance qualities make liquid glass an ideal material for waterproofing floor screeds in the bathroom.

1. Antiseptic properties provide reliable protection against mold and mildew.
2. As a water repellent, liquid glass forms a continuous, seamless water-repellent layer.
3. Antistatic characteristics ensure complete absence of electrification.
4. After treatment with this composition, the strength and durability of concrete increases.
5. A high adhesion coefficient ensures the penetration of liquid glass into microscopic cracks and pores.
6. By adding liquid glass to concrete mortar in proportions of 1:8, they achieve an increase in the hydrophobicity of the concrete structure.
7. Low cost and economical consumption of material when installing waterproofing floor screeds.

To complete the picture, it is necessary to point out some of the disadvantages of this waterproofing material:

• During operation, liquid glass can self-destruct in the absence of a decorative coating. If the finishing layer is not laid on such a screed finishing material, then the service life of the protective layer is limited to five years.
• Inadmissibility of use for treating brick surfaces (liquid glass contributes to its destruction).
• High fragility of the resulting protective layer.
• When pouring this material, it is necessary to strictly adhere to the deadlines specified by the manufacturer. Liquid glass hardens very quickly, so working with it requires certain skills.

Materials for impregnation waterproofing

The catalogs of manufacturers of waterproofing materials present a wide range of impregnations that have different characteristics. As an example, consider one such product.

The dry mix “Penetron” has a 3-component composition: special cement, quartz sand with a fine fraction and special chemical additives. This material belongs to the types of penetrating waterproofing. "Penetron" protects concrete structures from water and aggressive environments, and also helps to increase their strength.

The active fillers present in this material form hydrophobic barriers inside the concrete structure, providing protection of the screed throughout its entire thickness from moisture. This becomes possible due to the ability of the Penetron mixture to penetrate into the concrete structure 50 cm from the application surface. This best indicator among deep penetration impregnations presented on the domestic market.

In the case of using such a composition, liquid waterproofing of the bathroom floor after screed is applied to the moistened surface. After processing, the components of the mixture quickly penetrate into the concrete structure. This process is carried out due to the phenomenon of osmosis (the spread of molecules of a hydrophobic agent in concrete). During the chemical reaction that occurs inside the concrete, substances crystallize and lose their ability to dissolve in water. The result is a layer that does not allow moisture to pass through. The more the surface of the screed is moistened, the faster and more effective the chemical reaction will be.

The advantage of using this technology for waterproofing floor screed is that the resulting crystals are embedded in the crystal lattice of concrete. The result is a monolithic concrete layer that can effectively retain water that falls on the surface of the concrete, including under pressure.

At the same time, particles of the waterproofing mixture that penetrated into the concrete structure and did not react remain active. When microcracks appear into which water penetrates, they begin to work. As a result, the damaged surface is restored.

In its composition, “Penetron” resembles a gray homogeneous powder. This material must not include foreign matter or lumps. In dry form, its density is 1170 kg/m³, which is almost equal to the density of cement.

Concrete screed treated with Penetron improves a number of its performance characteristics:

• the waterproofing qualities of concrete increase three times;
• the strength of the screed increases by 5%;
• Concrete becomes resistant to acids and alkalis.

The finished mixture sets within 35–40 minutes after mixing. It takes about three hours for the solution to completely harden. The decorative covering of a screed waterproofed with Penetron can be laid no earlier than 14 days after treatment.

The components of this product are environmentally friendly and do not pose a threat to human health either during storage or during reaction with concrete.

Preparing the floor for waterproofing

Before you begin arranging the waterproofing of the screed, it is necessary to carry out a number of preparatory measures. You will need to completely empty the room of various objects, remove debris and even small particles of dust from the rough surface of the floor. It is necessary to level the surface to be treated, seal the joints of the slabs, as well as the gaps between the walls and the floor using cement mortar.

After the base of the floor is cleaned and well dried, you need to apply a primer to it. Primers dry quickly, so you can soon begin the main work.

Roll waterproofing of floors under screed in an apartment: 6 stages of work

There are two main types of roll waterproofing: adhesive and weld-on materials. The application of each of them has its own technological differences. To work with welded material, it is necessary to clarify how the waterproofing of the floor screed is heated (how to install it). For this, special construction burners are used. Installation of adhesive waterproofing is carried out by fixing it to the base of the floor.

The procedure for arranging the waterproofing layer:

This option for arranging a protective layer of screed is inexpensive and reliable, but the procedure for performing the work itself is very labor-intensive. To apply waterproofing material, professional skills and special tools. In addition, it is worth protecting the resulting layer from mechanical damage.

How to make liquid waterproofing of the floor in an apartment before screeding

Let's take an example of how to waterproof a bathroom floor before screeding. The main stages of work are as follows:

• Before starting work, it is necessary to prepare the base of the floor. At this stage, you need to clean the surface from dust and various debris. The presence of dust does not allow the mastic to adhere to the base of the floor. In addition, if there are oil stains on the surface being treated, they can contribute to the destruction of the waterproofing layer, so they must be removed without fail. All protrusions should be knocked down, and microcracks and other defects in the base should be repaired with cement mortar.
• To increase the adhesion of the mastic, the surface of the base must be treated with a primer. It is better to use a deep penetration primer (primer) from the range of the same manufacturer that produces mastic. After application, the primer must dry for two hours. When performing work, you should follow the manufacturer’s recommendations, which are indicated on the packaging of the composition.

• The mastic is spread over the surface of the subfloor with a roller or brush. It is necessary to apply several layers of the substance. In this case, you need to let each layer dry for 3-4 hours. Please note that layers should be applied no more than six hours apart. After this period, in most mastics the polymerization process is activated, as a result of which the subsequent layer will not adhere to the previous one.

When arranging waterproofing of a floor screed, we recommend that you take into account that each layer should be applied only in one direction. Thus, perpendicular application of the subsequent layer of mastic will increase the reliability of protection.

Using the same technology, it is necessary to carefully process the joints between floor slabs, between floors and walls, as well as in places where pipes pass. The applied mastic strip must cover the surface to be treated by 150 mm on all sides. In rooms with high humidity (bathroom, bathroom, kitchen), waterproofing should be done over the entire floor area (in such rooms, to increase the effectiveness of protection, it is better to use several methods of waterproofing treatment). The process of complete drying of the mastic takes up to 48 hours.

Video:

Liquid waterproofing under floor screed has a number of advantages. It is completely safe for human health, is fire resistant and highly reliable. Its application does not require a large number of tools or special qualifications of the performer. Disadvantage liquid waterproofing experts call it a low degree of resistance to mechanical damage.

Waterproofing for floor screed in an apartment using plaster

The main stages of work on forming a protective layer on the screed using plaster compounds:

Stage 1. Prepare the mixture according to the manufacturer's instructions.

Stage 2. Apply the first layer of plaster waterproofing and let it dry for a quarter of an hour.

Stage 3. Apply the second coat in a direction perpendicular to the direction in which the starting coat was applied.

Stage 4. Using the same technology, apply a third and, if necessary, a fourth layer of waterproofing composition.

Stage 5. Over the course of 24 hours, it is necessary to periodically moisten the formed protective layer. After this, it should dry for about two weeks with periodic moistening in the first days. During this stage, it is necessary to protect the waterproofing layer of the floor screed from mechanical damage.

For mixtures such as plaster waterproofing of floor screeds, prices on the domestic building materials market are very low. The advantages of this method also include the absence of the need for special equipment and tools, and the obvious disadvantage of this technology is the long drying time of the waterproofing layer.

Penetrating waterproofing of concrete floor screed

The main stages of work on waterproofing screeds using penetrating materials:

1. Unlike other technologies, preparation for applying penetrating waterproofing involves not only cleaning the concrete surface and filling microcracks, but also abundantly moistening it. The concrete surface must be well saturated with water (take precautions so as not to flood the neighbors below).
2. If you purchased a dry waterproofing mixture, you must make a water solution in accordance with the manufacturer's instructions.
3. Before applying the prepared composition, you need to wet the concrete base again.
4. After applying the first layer of solution, you must wait some time until it dries (the waiting period must be indicated in the manufacturer's instructions). After this, you need to moisten the surface and apply the penetrating mixture again.
5. After applying several layers of waterproofing composition, the treated surface must be covered with film. The base under the screed should be periodically moistened for 14 days, after which the floor should be completely dried.

Features of waterproofing a wooden floor under a screed

Wood flooring requires especially careful waterproofing. This is because wood absorbs moisture well and quickly deteriorates in high humidity conditions. The structure of a wooden floor is as follows: a rough base, a thermal insulation layer, waterproofing and a finishing coating. In addition, one of the intermediate layers of such a structure can be a heated floor system. You need to select materials for waterproofing a wooden floor based on the following criteria:

• light weight;
• excellent waterproofing characteristics;
• high strength of the waterproofing layer;
• durability;
• ease of application.

1. To ensure effective polymerization of mastic and other coating materials, after applying them, you need to wait a certain time specified in the manufacturer’s instructions. Only after this can you begin laying the finishing coating. In addition, experts recommend applying mastic in at least two layers (in this case, you need to wait until the first layer dries well, and only then apply the next one).
2. Layers of coating waterproofing under the floor screed are applied perpendicular to each other. After the last layer has dried, you can carry out work on pouring the screed or laying the decorative coating.
3. When treating the base of the floor with mastics, you need to coat the surface of the adjacent walls to a height of at least 120 mm in height. This will allow you to form a reliable waterproofing bath.
4. To calculate how much it will cost, for example, to waterproof a bathroom floor screed, you need to determine the amount of coating material required. For 1 m2 of concrete surface, at least two kilograms of the finished composition will be required. It should also be taken into account that to waterproof the joints between the wall and the floor surface, a special sealing tape is required.
5. Using cement-polymer mastics, you can not only create a moisture-proof layer on the base of the floor, but also level the surface and raise its height to the required level. The advantage of such compositions is that after waterproofing the subfloor, there is no need to install a screed. After this, you can immediately begin laying the finishing coating.
6. You can prepare the composition for plastering waterproofing of the base under a floor screed with your own hands. To do this, you need to make a regular cement mortar with the addition of a waterproofing mixture. First you need to clean the base of the floor from debris and dust, and then apply the first layer of prepared cement mortar. After this, you need to wait about 15 minutes until the solution dries. Then you need to apply about three or four more layers of solution in the same way.

After the final layer is applied, the surface of the base must be moistened with water every three hours for 24 hours. A day after the formation of the waterproofing layer, the base will be ready for further work.

The price of waterproofing a floor under a screed from professionals

When ordering the service of waterproofing a floor under a screed, the price for the work is calculated taking into account several factors:

• floor area and room features;
• deadlines allotted for work;
• materials selected for waterproofing the screed;
• the need to perform additional work.

How much it will cost to waterproof a floor under a screed (price per m2) at your facility can be accurately calculated only after specialists have visited and drawn up a repair estimate.

Today, on the domestic building materials market, it is quite possible to buy waterproofing for floor screeds at an affordable price. Therefore, even high-quality waterproofing materials are available to not very wealthy homeowners.

Average prices for some types of materials for waterproofing floor screeds:

Name	Price, rubles
Waterproofing based on fiberglass, 2.5 mm, 9 m 2
Uniflex from Technonikol, 3 mm, 10 m 2
Ruberoid, 15 m 2
Glassine, 13 m 2
Technoelast from Technonikol, 4 mm, 10 m2
"Aquastop-Perfecta", 20 kg (coating)
“VodoStop” SHLIMS, 20 kg
Mastic Flachendicht, “Knauf”, 5 kg
Bitumen mastic, 20 kg
Rubber mastic, 22 kg
Construction bitumen, 25 kg
Bitumen primer, 20 l
Bitumen primer from TechnoNIKOL, 20 l

For reinforced concrete floors in rooms with high humidity levels it is better to use Betonokontakt penetrating waterproofing.

Cooperating with the “My Repair” Company is reliable and prestigious. The specialists working here are professionals the highest level. The company "My Repair" operates throughout Moscow and the Moscow region.

In order for the finishing floor covering to last longer, it must be laid on a high-quality subfloor, which can only be obtained if the floor is waterproofed under the screed. Without waterproofing, dampness and moisture accumulate in the ceilings, and cracks form in the concrete. Therefore, work on arranging waterproofing is very important, regardless of the room in which the renovation is being carried out: in an apartment or a private house. Methods of applying a waterproofing layer:

• using roll materials;
• coating compounds;
• impregnating solutions;
• using plaster.

Roll materials

Arranging waterproofing using roll materials (this method is also called lining) is the simplest and budget option. These materials (PVC films, roofing felt, roofing felt), for the production of which bitumen, fiberglass or synthetic compounds are used, are divided into built-up (laid using a burner); adhesive (fixed on bitumen mastic); and those that are secured with nails and staples.

Technology for arranging adhesive waterproofing

The arrangement of the insulating layer is carried out by gluing roll material in several layers on the prepared base. Waterproofing the floor before the screed:

• We dismantle the old floor covering (if the insulation is done in the old room).
• On the concrete base, we chop off or knock down all the protrusions, cut off the protruding reinforcement, remove any cutting or piercing objects (for example, protruding nails), and process the joints of the slabs.
• We clean the base from construction debris and dirt.
• We prime the base (for better adhesion of the waterproofing material to the concrete).
• We fill cracks and potholes with cement-sand mortar.
• We unroll the insulating material, clean it of dust and powder, and leave it spread out for 1 day (this will prevent the appearance of waves and swelling when installing the waterproofing).

• We “cut” the canvas according to the measurements, not forgetting to leave allowances for laying the material overlapping (10 cm); in order to place it on the wall (20 cm); as well as in places adjacent to the threshold, for laying material into the adjacent room (30 cm).
• We lay the first layer of mastic (it can be cold or hot: the thickness of the cold layer is at least 1 mm, and the hot layer is at least 2 mm) or glue, on which we place the waterproofing sheet.

Advice! In order to fix the waterproofing sheet, it is enough to heat the side adjacent to the base with a gas burner and press it firmly against the surface.

• We stretch the material, removing wave formation.
• We apply the next layer of mastic and lay the second layer of rolled insulation (the number of layers can vary from 2 to 4: the more, the higher the reliability of the waterproofing).
• After laying all the insulating material, all joints must be additionally coated or heated.
• Upon completion of the work, knock on the surface to identify un-glued areas.
• If there are any, we proceed as follows: make cuts, dry the surface, coat with mastic, apply overlapping patches.
• Dry the surface thoroughly.
• Carefully trim off the excess insulating material.

Important! For waterproofing, do not use materials with a cardboard base.

Pros and cons of adhesive waterproofing

A waterproofing layer of this type lasts a long time (18 years or more), is not damaged by the formation of small cracks in the base of the floor, and is relatively inexpensive. But when installing waterproofing, care must be taken to ensure that the surface on which it is laid is flat, dry and clean (in some cases, primed). Insulation also needs protection from mechanical influences and does not fit well where the floor meets the walls. When arranging it, you must remember about fire safety measures.

Coating compounds

The coating technique of applying a waterproofing layer is the most common way to protect the base from moisture. Coating compositions are bitumen, rubber, polymer, bitumen-polymer and polymer-cement mastics and solutions.

Technology for arranging insulation using coating compounds

The sequence of work is as follows:

• We are carrying out the planned replacement of communications.
• We prepare the concrete base: special attention should be paid to removing oil stains, traces of solvent and other chemically active substances, since their interaction with coating waterproofing compounds is extremely undesirable.
• We prime the base with a composition (primer) that is suitable for the selected coating material.
• We fill cracks and potholes with a cement-sand mixture.
• Using a spatula or a brush with stiff bristles, apply mastic to the surface of the concrete base, moving from the wall opposite the entrance; We additionally carefully coat the junctions of the floor with the walls and around the pipes.

• After the first layer of mastic has dried, apply the next one (the number of layers can reach 3÷5: see the instructions on the package). We lay each subsequent layer perpendicular to the previous one.
• After 2 days we make a screed.

Advice! When loaded, the metal reinforcing elements of the screed can damage the waterproofing layer: therefore, special plastic “chairs” are used for their installation.

Advantages and disadvantages of coating waterproofing

Coating waterproofing, with which you can achieve a seamless and highly reliable coating, is in great demand among people who value their time, money and effort. Coating compounds can be used to fill any cavities, even the most inaccessible ones. These materials have good adhesion to concrete and other building materials, so they can be applied to almost any surface. The disadvantages are: poor resistance to temperature changes and mechanical stress, as well as loss of waterproofing properties due to constant vibration (for example, if there is a highway or railway nearby or construction is underway).

Waterproofing with liquid penetrating compounds

Installing insulation using liquid penetrating compounds is a relatively new technology. The penetrating composition is a dry mixture based on cement, aggregate and a specially selected complex chemical components, diluted with water. The waterproofing composition enters into chemical reaction with the surface material on which it is applied, resulting in the formation of insoluble, needle-shaped, randomly located crystals that fill microcracks and pores (up to 0.5 mm). They become an integral part of the structure of the concrete base, changing its properties and preventing the penetration of moisture.

Penetrating waterproofing technology

The technology for applying penetrating waterproofing is similar to previous technologies.

Important! Impregnation waterproofing is not effective when applied to concrete with a low waterproof grade, gypsum and lime plaster. It is best suited for new concrete under a thin concrete screed.

Advantages and disadvantages of impregnating waterproofing

Advantages: provides protection for concrete for its entire service life; when arranging it, there is no need to level, dry and prime the surface on which it is applied; It is resistant to mechanical stress and has the ability to “self-heal” when new pores and cracks form. The only drawback is the high cost of the material.

Plaster waterproofing

Plaster waterproofing under the screed (“water stop”) consists of a dry mixture containing cement, sand and special components that prevent the penetration of moisture.

Dilute the dry mixture with water and stir; apply mechanized (shotcrete) or manually to a dry prepared surface in 2÷3 layers with an interval of 15 minutes; moisturize over the next 24 hours waterproofing coating, spraying water every 4÷5 hours; leave to dry for 2-3 days.

The advantages of plaster waterproofing are: ease of application, environmental friendliness of the composition, good adhesion with other building materials, durability, elasticity, and the ability to be applied to uneven surfaces. That is, using it, you can solve two problems at the same time: leveling the surface and waterproofing it. The disadvantages include: high cost and the fact that this process is very labor-intensive.

In conclusion

Waterproofing floor screeds is especially important in rooms with high humidity: bathrooms, showers, toilets and kitchens. The quality of insulation depends on the choice of material, installation method and the skills required to perform such work.