Bathroom waterproofing

Bathroom waterproofing is a waterproof and anti-moisture insulation, i.e. limiting the penetration of water and water vapor through leaks in the room. In this way, we not only protect our own apartment, but also prevent flooding of the premises located below us. We explain which waterproofing for the bathroom will be the best for your needs and how to do it correctly.

What does a waterproofed bathroom give us?

Is waterproofing a profitable and necessary investment? The answer to this question is best illustrated by the negative effects of not waterproofing a bathroom:

• penetration of water and moisture into the rooms adjacent to the bathroom - not only in your house or apartment, but also at your neighbors;
• destruction of structural elements that are exposed to moisture - walls, ceilings, floors;
• fateful consequences of flooding;
• an ideal environment for the growth of mold and other fungi that can lead to health problems, and their elimination can be an expensive and time-consuming job;
• falling off tiles and terracotta and other unsightly damage in the bathroom.

It's easy to come to the conclusion that waterproofing has many more pluses than minuses (to which you only need to spend time and money). Provides effective protection of walls and floors against moisture due to an additional protective layer under the tiles.

People who have a shower without a shower tray are particularly vulnerable to the above-mentioned problems.Tiles and grouts alone do not provide sufficient protection against water. Even worse, the water that collects under the ceramic tiles does not make itself felt immediately - usually the effects of leakage become apparent when the damage is already very advanced and mold appears or you just flood your neighbor.

How does bathroom waterproofing work?

Waterproofing the shower, sink, walls and floor has one main purpose - to keep water droplets on the surface of individual elements of the bathroom. Laying tiles and other decorative and finishing elements is planned only after waterproofing the bathroom. To prevent water from getting into the next layers, we apply special materials to the above-mentioned places, the so-called insulating coatings that inhibit its penetration, and only then tiles. So, waterproofing the bathroom is done when building from scratch or doing a major renovation.

What happens to the water that remains on the surface of the entire floor, tiles and joints thanks to the insulation? It is discharged from the room by means of ventilation. Therefore, waterproofing a bathroom must go hand in hand with an efficient air flow system.

Does the whole bathroom have to be covered with moisture-insulating coatings? The most sensitive points are wet zones exposed to direct contact with water. For waterproofing, special preparations described below are used. To other zones, i.e. damp, adequate protection will be provided by tiles or bathroom paints.

Wet zones that require careful bathroom insulation are:

• the entire floor,
• walls around the bathtub, washbasin, shower cubicle,
• connections at the bathtub, washbasin, paddling pool,
• wall corners,
• contact of the tiles with other materials (e.g. with a mirror),
• edges of rubber collars (in installations passing through ceilings and walls in the bathroom).

What do you need to waterproof your bathroom?

The shopping list for waterproofing a bathroom must include:

• leveling mortar,
• ground (optional),
• sealing tape,
• sealing cuffs / collars,
• liquid foil for sticking tapes and collars in sensitive places,
• liquid foil, polyurethane mass or other insulating material for other wet zones,
• brush or paint roller.

If the bathroom has underfloor heating, choose a heat-resistant foil.

Step-by-step waterproofing of the bathroom

Precisely made anti-moisture insulation prevents water from penetrating into walls and floors for many years. So, we explain what waterproofing of the bathroom looks like step by step:

1. Cleaning and leveling the surface

Insulation coating will be applied to the walls and floor - the entire effect depends on it, so prepare the substrate first. The surface for waterproofing materials must therefore be clean and even. There is no place for particles and stains here. We remove dust, dust and remains of paint or other finishing materials. If mold has already appeared in the bathroom and we only discover it during renovation, appropriate chemicals come to the rescue.

Check the hardness of the surface. We have to level it (e.g. with a special mortar). We remove defects and scratches, hammer loosening, matt plaster and screed. In addition, under-tile insulation can only be made on a dry substrate.

2. Priming the surface for insulation

A clean, even and dry substrate can first be primed if necessary. If the surface is very absorbent, such as gypsum, you can use a system primer. Thanks to it, the insulation under the bathroom tiles will have even better adhesion. . Apply the emulsion with a roller or a paint brush, preferably two layers at a time. We wait for the primer to dry according to the manufacturer's recommendations.

3. Waterproofing of corners and pipe penetrations

All insulation must be performed with great precision, but the sealing layer at critical points in wet zones - wall corners, wall-to-floor joints, system outlets and pipe penetrations is of key importance. You will need:

• sealing collar - for interior and exterior bathroom corners and pipe penetrations.
• sealing tape made of coated polyester fabric - glue it along the perimeter of the bathroom where the walls meet the floor.

The insulating tapes and sealing collars are glued with liquid foil. We start by putting the foil in place on the tape or collar, which we then glue.

4. Waterproofing the entire bathroom

After the corners, places of contact and the installation area have been secured, it is time to cover all wet areas with an insulating layer. We have various solutions to choose from:

liquid foil - special compounds for waterproofing called liquid films are made on the basis of polymer dispersions. To perform such waterproofing, you will need a paint roller or a brush. First, we mix the mass well. We apply the first layer, rubbing it strongly on the entire floor, walls, by the shower, bathtub and washbasin to a thickness of approx. 1 mm. We make straight, parallel strands. We wait a few hours as recommended by the manufacturer and apply another layer of liquid foil. Importantly, the second layer should be applied perpendicular to the first to create a flexible, seamless and sealed system;

polyurethane liquid membrane - also provides excellent insulation, is very durable and allows the floor to "breathe". We also apply it with a roller or brush or use airless spray. The strength of the membrane is evidenced by its popularity in waterproofing swimming pools, roofs and terraces;

elastic sealing slurry - the so-called the micro-mortar must first be diluted like ordinary cement mortar and mixed with water. We also apply two layers with a metal trowel, brush, roller or roofing brush. The first is placed on a damp surface, and the second - a little thicker - immediately without waiting for the first to dry.

5. Laying tiles

The waterproofing of the shower cubicle, walls, floor and other wet zones must dry before proceeding to tiling and tiling work. First, we prepare the mortar - the instructions can be found on the packaging. It has to be combined with water in appropriate proportions using an electric stirrer and applied to the wall with a metal float. Then we apply the tiles, taking special care not to damage the waterproofing layer.

6. Grouting

To make the waterproofing of the bathroom even more effective, make joints with a special jointing mortar, thanks to which the surface will not soak up water. Choose an agent that has biocides to prevent mold. The joints at the bathtub, shower tray, sink and at the contact point of the lining with other materials can be made of sanitary silicone. After applying the grout, clean the surface of the tiles.

FAQ:

Waterproofing the bathroom - is it worth doing?

Definitely yes - it protects the bathroom against mold growth, and the adjacent rooms against flooding. Thanks to the waterproof and anti-damp insulation, the structural elements of the bathroom are not exposed to water penetration, and thus - damage.

How should a bathroom waterproofing be done?

We clean and level the surface. We glue the tape and sealing flanges at the corners of the walls, around the installation, where the walls meet the floor and tiles with other materials. We put a liquid foil or other isolating preparation on the entire surface of wet zones - at the sink, bathtub, paddling pool, etc.

Can you waterproof your bathroom yourself?

Yes, but it is not an easy task. Insulation of the bathroom must be done professionally to be effective at all. Therefore, it is best to entrust it to professionals who have experience and knowledge in the field of construction.