How not to soak the neighbors: proper waterproofing in the bathroom

How not to soak the neighbors: proper waterproofing in the bathroom

A flood in the bathroom or toilet is not uncommon for residents of modern megacities. At a minimum, such an emergency is fraught with payments to flooded neighbors. And your own apartment, most likely, will also have to be repaired. Waterproofing is one way to prevent flooding, which means saving you nerves and money.

Types of waterproofing
Waterproofing is used at different stages of construction for a variety of tasks. It protects the foundation from moisture, protects the roof from precipitation, saves from the appearance of efflorescence on the lining … There are about a dozen types of waterproofing. We will consider those that are used at home (usually in the bathroom).

Pasting waterproofing is performed using waterproof roll materials. They lay out the floor and part of the walls. The joints of the sheets are welded or glued, forming a continuous “pool”. Such waterproofing is placed on the subfloor under the finishing screed. There are options that allow you to lay finishing materials directly on the waterproofing, without any screed.
Coating and colorful waterproofing are carried out using mastics. These materials are applied to the prepared surface with a spatula, brush or roller, depending on the material. Coating waterproofing is applied to the finishing screed directly under the finishing material. Coating with bituminous mixtures is applied under the finishing screed (some mixtures even replace it).
Stucco waterproofing is a cement or gypsum mixture that has received water-repellent properties due to polymer additives. It is applied with a spatula to the subfloor. Such waterproofing can act as a finishing screed.
Impregnating waterproofing is a liquid that penetrates into the pores of a building material. It makes the coating waterproof. There are, among other things, colorless impregnations. Therefore, such waterproofing can be applied at any stage, including at the finishing stage, on top of finishing materials (tiles or plasters).
Waterproofing in the bathroom is mounted throughout the wet area. This includes the floor, 10-20 cm of the wall adjacent to the floor, as well as areas around the sink, bathtub, bidet, and so on. In general, everything where splashes of water can get.

Gluing waterproofing
Rolls of pasting waterproofing are overlapped, going onto the walls by 10-20 cm. The main difficulty in laying is bypassing pipes, complex corners and non-standard floor elements. Often in such places it is necessary to combine adhesive insulation with coating insulation.

Pasting waterproofing is of two types: built-up and self-adhesive. The surface is laid using a gas burner or a technical hair dryer . The underside of the roll is heated to the bitumen melting point, then the roll is unwound, securely bonded to the floor material and other waterproofing sheets.

Built-up waterproofing is inexpensive (from 15 rubles / m 2 ), but requires certain skills for laying. In addition, bitumen releases toxic substances when heated. Therefore, in confined spaces, this option can become dangerous.

Self-adhesive waterproofing is much easier to install. It does not require any special skills or additional tools – a clerical knife is enough. Such waterproofing can lie freely on the floor. This allows you to use it in rooms with moving floors – for example, made of wood or plywood.

There are options with the possibility of laying tiles directly on the insulation. This is the best option for frame and wooden houses, where the supporting structures do not allow concrete screed under the tile. The price of self-adhesive waterproofing is higher than that of welded waterproofing – from 300 rubles / m 2 .

Coating waterproofing
Coating waterproofing is a ready-made liquid mixture that is applied in a few words to the wet areas of the bathroom. Its main advantage is the ability to cover any surface shape, including pipe entries, corners and drains. And the floor itself does not have to be even. Differences between the plates, cracks and small irregularities are quite allowed.

Thick mastics are applied with a spatula, liquid – with a brush or roller. Many mastics can be thinned with a solvent. This makes them easier to apply with a brush. The types of solvent and the maximum degree of dilution are usually written on the packaging.


bituminous, quick-drying, 5 kg
Mastic is placed in several layers with a thickness of 1-3 mm. Each layer must be completely dry. A layer of quick-drying mastic dries in 2-4 hours, a layer of simple mastic can dry up to several days. Keep this in mind when buying: waterproofing a floor in three layers (including primer treatment) can take a week or more.

The cost of coating waterproofing with polymer mastic is above average – from 300 rubles / m 2 . Primer treatment adds at least 50 rubles / m 2 to the amount . Bituminous and tar mastics will cost less. However, they are not recommended for indoor use. Materials have a pungent odor, are toxic and dry for a long time – up to five days.

Plaster waterproofing
It is laid in the same way as thick coated waterproofing – with a spatula over all protected areas. Sold as a dry mix. Before use, it should be prepared by mixing with a certain amount of water.

Plaster waterproofing mixtures are about half the price of mastics (from 130 rubles / m 2 ). They can be used as leveling screeds. Such waterproofing has a number of disadvantages:

Inexpensive cement mixtures have high rigidity. They cannot be used on deformable bases. More expensive cement mixtures with polymer additives do not have this drawback. However, they are comparable in price to mastics.
Cement waterproofing mixtures cannot be used in contact with walls lined with gypsum plaster (Rotband, Volma, Yunis). They react with gypsum and this deforms the materials.
Impregnation waterproofing
This type of waterproofing is applied with a brush or roller. It penetrates into the material to a certain depth, changing the structure of the coating. Such impregnations are called water repellents.

The impregnation is applied to the material until the absorption stops. Drying time depends on the surface material and brand of water repellent. Usually it does not exceed 3-5 hours. Another advantage of impregnating waterproofing is that it does not change the thickness and texture of the treated surface (and sometimes does not change color). This allows you to create a water-repellent layer directly on the topcoat – a plastered or tiled wall.

Water repellent ADMIRAL

universal, acrylic, 5 l
High-quality reliable water repellents are quite expensive – from 350 rubles / m 2 . Of course, in stores there are many impregnations cheaper. However, they are easier to wash out and “hold” water worse.

Leak sensors and smart taps
Waterproofing does not guarantee the absence of leaks – it only keeps a certain amount of water inside the room. If water is leaking from a broken washer or just hitting the floor from a leaky shower stall, waterproofing will help. But in the event of a serious accident, it will not be of much use.

Therefore, waterproofing should be installed in combination with other means of protection against flooding. You can put a smart leak sensor. When water appears on the floor, he will send you an SMS message – and you may have time to go home before the insulation stops “holding” the water.