Both during construction and when repairing a bathroom, preliminary waterproofing of the floor in the bathroom under the tiles is very important, especially if there are rooms below and you want to avoid flooding them in the event of a possible communication failure. Let's look at a number of materials that are commonly used for this purpose.
Why do waterproofing under the cladding
Imagine that during water procedures a certain amount of water splashed out of the bathroom onto the floor and in such a situation ask yourself if waterproofing is needed in the bathroom under the tiles. There are no ceilings that are absolutely impervious to liquid, often there are gaps at the joints between the slabs, minor gaps near the communication pipes passing through the floors. Accordingly, water will easily seep down, and if this happens in an apartment, the decoration of the neighbors' premises can be seriously damaged. Well, in a private house, the damage will be done to you, which is also unpleasant. Waterproofing will prevent such a situation, and with high thresholds you will have enough time to react until the water rushes into the hallway.
By flooding the premises located on the floor below, water can go through the channels made for electrical wiring and cause a short circuit and, as a result, a fire.
But flooding is not the only problem that can arise from the frequent wetting of floor tiles. Leaking between the seams of the cladding, where the grouting of the tile is not done well enough, the water begins to gradually saturate and then destroy the concrete, regardless of whether it has been treated with soils or not. Therefore, it is advisable to carefully cover concrete surfaces with coating mixtures or special films in order to isolate them from possible moisture ingress. Water can get under the tile even with a good grout, in places where it adjoins communications or along the edge of the cladding along the walls. In this case, dampness will be an ideal environment for the growth of mold, which is harmful to both building materials and the health of residents. Waterproofing can solve this problem too.
How to use waterproofing - the main places of processing
It is necessary to protect not only the floor from the penetration of moisture, but also partially the walls. As a rule, the corners of the room where the baseboards are located, that is, along the walls along the perimeter, are considered the most problematic areas. Therefore, when processing with waterproofing, it is recommended to capture vertical surfaces at least 10 centimeters, and preferably 0.3 meters up. However, there are areas that require special attention. In particular, in places where pipes pass through ceilings, whether it be water supply or sewerage. Around communications, waterproofing should be put especially carefully. If it is a mastic coating or a pasty plaster mixture, then in several layers.
You also need to waterproof the walls of the bathroom, where plumbing will be installed, so that water does not get under the tiles. It often happens during water procedures that the hand accidentally clamps the mixer tap and the jet hits the wall. Just in such situations, moisture flowing down the tile can get under the cladding where it is not made very well. Therefore, it is recommended to cover the entire area with waterproofing, where water can accidentally or inevitably, as, for example, when turning on the shower, get water. This is 50 centimeters to the sides and up from the sink, 0.5 meters to the sides of the bath and from it up to the very ceiling. You should not bypass the water closet, since condensate often accumulates on the tank, and the possibility of leakage should not be ruled out.
Materials that are used as waterproofing
If you are planning to protect the ceiling in the bathroom from all-penetrating moisture, you have a fairly large choice. To date, there are several types of waterproofing materials: coating mastic compositions, paste-like plaster polymer-cement mixtures and films for pasting roll format. There are also separate penetrating compounds that, after drying, close microcracks and voids between grains in concrete, providing a sufficient degree of moisture resistance. As a separate material, one can also mention sprayed waterproofing made on the basis of liquid rubber.
Among other things, special aquapanels are used as an additional insulating coating, which cover the floor and, partially, the walls. Any of the listed materials is already applied or glued on top, which provides multi-layer waterproofing in combination with primers for concrete surfaces. Coating compositions are made on the basis of mastics, including bitumen, and latex is used as the main component, in combination with it or separately from it, very fine rubber crumb is added. A number of roll materials also have a bitumen base. Cement compositions are necessarily supplemented with plasticizers, often polymeric. Let's look at the existing options in more detail.
Mastic compositions - varieties, features of use
Compositions for coating surfaces can be applied with a roller or brush, that is, their consistency is quite liquid. These are the so-called mastic waterproofing mixtures, which are produced on the basis of bituminous resins or polymers. There are formulations with latex as a plasticizer. It is quite easy to process floors and walls with them, they have excellent adhesion and often there is no need even to specially prime the surfaces, it is enough to clean them of dust and dirt. Some mixtures can only be used with an organic solvent.
A special mesh with a hydrobarrier strip is laid on top of the coating in the corners, and it is better to choose options specifically for the corners, after which another layer of the mastic composition is applied. This provides the most reliable waterproofing.
The main requirement for such coatings is that they cover the floor and walls with moderate humidity and at a temperature of 20 degrees or higher. This is a definite minus, since it is necessary to create certain conditions for work. Cold makes these mixtures hard and brittle, especially if the freezing process occurs at low temperatures. Another drawback is the very long drying of the applied waterproofing, especially since the layer must be thick enough. The advantages of such compositions include a rather low price, which allows them to be used in large volumes of work. In addition, they are easy to find on sale, and the choice is very extensive.
Polymer cement compositions - use cases, advantages and disadvantages
The simplest solution is to make a concrete screed by adding it to the mortar, but this option still does not solve the problem with joints near the walls, where you need to leave some gap when pouring. Therefore, special paste-like compositions based on cement with the addition of polymers or other plasticizers are much more effective. This is a dry waterproofing for the bathroom in paper bags, which must be diluted with water, after which a thick paste is obtained. Its advantage is that cement provides strength after drying, and polymers, penetrating into any cracks and microcracks, create a film to isolate the floor from water.
Like mastic compounds, cement mixtures are available and very inexpensive. This is their main advantage. In addition, another plus is the ease of processing with mixtures of surfaces, for this a conventional spatula is used. The polymer cement composition is diluted to the consistency of thick sour cream, after which it is applied in portions to the floor and walls, and smoothed. Areas where pipes pass in the ceiling are more convenient to brush, rubbing the mixture into the cracks. The composition begins to solidify after 5 minutes, but to complete the polymerization process, at least a day must pass before further finishing can begin. Such a long drying time is a significant disadvantage.
Roll waterproofing - a small analysis of existing options
Perhaps the fastest way to deal with the processing of the floor and walls in the bathroom is with the help of special films or other materials sold in rolls. Among them there are those that are applied by heating, or self-adhesive. The second type is more convenient, it is enough to remove a special protective coating to open the adhesive layer. The most affordable option is bitumen-impregnated weld materials, such as roofing felt and roofing material, which need to be heated with an open flame, for example, a gasoline or gas burner, until the mass on the back becomes sticky enough. The main disadvantage of this type is a pungent smell that does not disappear from the room for a long time. Also, the fragility should be attributed to the minuses. The main advantage is low cost.
Self-adhesive materials are somewhat more convenient, since they do not require much effort. As already mentioned, the protection breaks down and everything can be gently applied to the surface. However, difficulties arise when pasting those places where communications pass. It is not recommended to cut the membranes, and if pressed as is, wrinkles may form. Alternatively, you can combine films with mastic compositions, this will allow you to isolate difficult places well. It is enough to warm up the bituminous ones to make neat joints, so it is difficult to judge which bathroom waterproofing for tiles is more convenient and which is better to use. But self-adhesive roll materials have an undoubted advantage - they are very durable, and in relation to quality, the price does not look too high.
