Waterproofing the bathroom floor with mastic: Instructions + Video

Waterproofing the bathroom floor with mastic: Instructions + Video Mastic for waterproofing the floor in the bathroom: types, application features Nobody will even argue with the fact that the level of humidity in the bathroom is capable of reaching prohibitively high rates. Because of this, the repair work of such a room can be called specific. You cannot use ordinary materials that will not be afraid of moisture. It follows from this that only ceramic tiles and other materials that are resistant to moisture can be used for finishing work.

In addition, due consideration should be given to waterproofing the bathroom floor.

Mastic for this task will be an excellent assistant, but if this is not done, then be sure that all materials will begin to deteriorate after a short time. There are many different methods on how to create waterproofing in a bathroom, and they all have excellent characteristics. Let's learn more about them and learn about the use of mastic.

General information

Types of waterproofing for the bathroom floor

First, you should find out what are the main options for waterproofing the bathroom floor, and in fact there are enough of them, and each option has its own advantages and disadvantages. When we look at them, the principle of working with them will become clearer, and you will also understand why it is most convenient to use mastic for waterproofing.

There are such types of floor waterproofing in a wet room, and they differ in the type of application:

It is impossible to single out one of the ways, and say that one is better than the other, since even experts argue about this. Everything is reduced to the fact that the choice is based on different factors, namely the surface features, the timing of the work and so on.

If in some particular case it is better to use cast-type waterproofing, then plastering may simply not work.

But still, it is worth noting that in the most ordinary conditions it will be easier to perform work with a coating type of waterproofing. As well as surface preparation, the process is quite simple, you just need to buy the right tools and materials. Let's find out how a bathroom is waterproofed with mastics, and what may be required to complete the work.

Features of coating materials

Those people who are little familiar with this method of finishing in the bathroom, only after reading the name will be able to understand what the technology is application.

Indeed, since most of the work is reduced to applying the material to the floor surface and other surfaces that need to be processed. It is only important to determine which materials are used by the master to perform the coating work. These are fairly simple materials, and even beginners can handle them.

Below there is a list of compositions and varieties of mastics for coating:

  • Bituminous.
  • Bitumen-polymer.

  • Polymeric.
  • Bitumen-rubber.
  • Water based, acrylic based.
  • Cement-polymer.

Waterproofing the bathroom floor with mastic: Instructions + Video As you can see, there is plenty to choose from a mastic for waterproofing the bathroom floor.

Each composition is unique in itself and has a number of features. Most often, it is the bituminous variety of mastic, or other materials based on bitumen, that is used for work. They usually have additives of organic solvents and other fillers, namely plasticizers, latex, rubber crumb. This helps to make the coating more elastic, which means it will be easier and more convenient to apply to the floor surface.

Note that this bituminous bathroom mastic has excellent adhesion (ie, adhesion to the surface) characteristics.

Due to this, it is possible to apply the material to both wooden and concrete floors without any problems.

Although, it would be unfair not to note that the material also has certain disadvantages that should be considered when working with bitumen-based mastic:

  1. With a large temperature difference, the surface can chip and crack.
  2. Biological corrosion is likely to occur.
  3. When waterproofing a bathroom with mastic, there may be an unpleasant odor.

Still, such shortcomings rarely stop users who want quality and durable repairs.

No wonder bituminous mastic has become so popular for waterproofing work. It copes with the task perfectly, has a low cost, is easy to apply and can serve for about 6 years without any other repair work. If we talk about polymer-type materials, then by themselves they do not have any negative qualities, and often silicone sealants are used for the bath. Application is simple, convenient, and can be used on floors and walls. Silicone-based lubricants are slightly more expensive, but they have excellent resistance to temperature changes, do not have a bad smell and will last longer, and they do the main task perfectly.

If we are talking about the consumption of materials, then such an indicator is always indicated on the packaging of the mastic. It will largely depend on factors, including the quality of the surface in the bathroom, as well as the number and thickness of layers. How to waterproof a room using these materials?

Stages of the coating process and preparatory work

The work itself is quite simple and with even a beginner in the field of renovation work inside apartments, who wanted to do everything with his own hands, can handle it. It is only important to carefully read the instructions, complete all the preparatory work, and also buy the required amount of all materials, and you can proceed by following the recommendations.An important condition is to do everything slowly and carefully.

So, let's start with preparation. First you need to go to a building materials store or to the market and buy a sufficient amount of coating-type waterproofing. It can be silicone (or any other) sealant, bituminous mastic. But before that you have to calculate how much material you need. This is easy to do if you find out the consumption of mastic for 1 m 2 (the data is indicated on the packaging with the material), as well as the total area of ​​the bathroom.

Based on the two indicators, calculate the required amount of material and complete the purchase. Now there is another nuance - materials of the coating type are sold in dry and liquid form, and if the second variety is immediately ready for direct application to the floor and other surfaces, then the dry ones still have to be brought to a liquid state.

This is not difficult to do, since usually on the packaging of the material, the manufacturer indicates the optimal proportions for creating mastic and detailed instructions are attached, and you only need to strictly follow it. Usually, everything is reduced to adding water to the mixture, and after mixing the contents using a construction mixer. The composition should be brought to a homogeneous consistency, which will resemble a paste or thick sour cream.

After that, you can apply a mastic to waterproof the bathroom floor.

Please note, that if you buy dry mixes and dilution liquid in a set, then according to the technology, the solution should be first mixed with water, and only after pour this into a dry mass. Such compositions are two-component waterproofing.

And what if you bought a ready-made bitumen mastic? Then the stage with dilution can be skipped, and you should immediately start preparing the surface. To do this, you need to take everything out of the bathroom, remove everything from the floor covering and clean it well.

Important! If the imposition of a waterproofing layer in the bathroom is carried out during a major overhaul, then everything is clear - the composition should be applied to the concrete-filled floor, and during normal repairs, all the floor covering will need to be removed to get to the surface of the old concrete.

Work should be done carefully, remove all types of dirt from the concrete surface. There should be no large debris or dust. Use a broom to remove unwanted elements and debris, but a vacuum cleaner will be much more effective, which can remove everything from the surface, and it will be ready for the rest of the manipulations. The second task that you face is the removal of grease stains that can be absorbed into the surface, or the remains of the paint mixture.

Yes, a perfectly clean surface is required for waterproofing. If there are loose areas on the floor, they need to be thoroughly cleaned, and then again remove debris and dust. The surface in this case will be almost completely ready to be processed.

Applying primer and insulating the surface

To improve the quality of work, adhesion to the surface (adhesion) and therefore, the life of the waterproofing layer, We recommend treating the surface with a deep penetration primer. What is it for? The composition will penetrate into every concrete pore, and after drying it will contribute to the high-quality adhesion of the mastic and the concrete floor surface.

In addition, the primer helps to enhance the sealing process. Application of the primer is straightforward and should be done using a roller.

It is also important to ensure that the composition is applied evenly in all areas. In no case should it be allowed to leave untreated places on the floor. Hard-to-reach areas like the battery and corners can be brushed with a regular brush.

When the first coat is applied, you should wait for it to dry a little and apply another coat. The rest of the work can be performed only after the composition is completely dry. This is written on the package, and usually this process takes about a day.

So, when the surface is ready for future treatment, it is time to waterproof the bathroom floor with mastic. As with the primer, the work is straightforward.

The sequence of work is as follows:

  1. Waterproofing the bathroom floor with mastic: Instructions + Video The process should be started with bitumen mastic treatment of wall and floor joints, pipe passages through the floor / walls and corners. Using a brush, the composition should be applied in one layer to these areas first. Pay attention that everything is even, there are no missing sections.
  2. To enhance the effect on particularly problematic areas, use a special waterproofing tape. You should not wait for the mastic to dry, and you can immediately stick the tapes on the joints of the walls and floor.

    It must necessarily overlap the joints, and prevent moisture from entering these places.

Please note that care must be taken to ensure that the tape is applied correctly.

It should be well straightened, and not have any folds, joints, waves:

  1. The stripes at the corners should be joined with an overlap of 50 70 mm, and for the initial installation, this area should be covered with mastic with an overlap.
  2. Following a similar principle, we recommend processing not only the joints of the floor and walls, but also the joints of walls with walls in the corners. It is not necessary to carry out processing along the entire height, 20-25 cm is enough.

  3. After that, a second layer of bituminous or any other type of mastic can be applied to the tape.
  4. Another place that requires special waterproofing is the water outlet and supply point. Sealing membranes must be glued to them, which must be treated from above with a waterproofing material.
  5. Further - it is easier, and all you need to do is to process the remaining surface of the floor and a little wall.When using a brush, you can treat the entire surface of the floor, as well as walls 25 cm high.

    Experienced people in this business recommend also treating the areas around the bathtub and washbasin at a height of 0.5-0. 7 meters. Due to this, the wall will not begin to damp, and mold will not form on it.

  6. The mastic layer should not be very thin as it is a protective layer.

    For this reason, it should be at least 0. 2-0. 3 cm thick. Also, it should be homogeneous, not different.

After the first layer of waterproofing material has dried, the second layer should be applied in the same way.

Sometimes even three layers are required. But keep in mind that waterproofing should be worn only in the perpendicular direction from the previous layer. It takes about 6 hours to dry one layer, since this will depend a lot on the type of coating material. This completes the waterproofing of the bathroom floor with mastic. Further finishing work can be performed after a day.


As you can see, due to this simple method, you can perform waterproofing inside the bathroom. As you can see, the work is simple, and the effect is excellent. Lubricating waterproofing is one of the simplest ways to create a bathtub that is reliable and protected from the negative effects of moisture. And most importantly, any person can cope with this, and do everything with their own hands.

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