Are all tile floors waterproof

Tile waterproofing

Sealing wet cells - this is how you make a tile surface waterproof

Tiles are almost waterproof, but still allow a certain amount of water to penetrate the substrate. This even applies to tile coverings that you grout with mortar based on synthetic resin. In order to protect the subsurface and thus the building fabric from moisture, waterproofing is therefore necessary. It not only prevents damage to the masonry, but also the formation of mold and is therefore a good precaution. In addition, it causes little additional work, because a seal can be painted.

Particularly important: the sealing of the shower cubicle

Most of the water naturally penetrates through the tiles in a closed or open shower cubicle and around a bathtub with shower function. There is a constant stream of water that causes the joints to wear out, so that over time more and more water penetrates through the tile covering. In a bathroom, however, the floor often gets wet. In the bathroom, you should therefore seal both the walls and the floor. On the walls, however, it is sufficient to apply the sealant to a height that is 30 centimeters above the shower head or 20 centimeters above the water inlet of a bathtub. In other tiled rooms, too, you can paint a seal before laying the tiles. However, this is not absolutely necessary even in the kitchen.

Note: If you only want to seal the floor, you should paint the walls up to a height of at least 15 centimeters.

To seal a wet room you need

  • possibly repair filler to touch up damaged areas
  • Detergent and a vacuum cleaner
  • a primer if the surface is very absorbent
  • seal
  • brush
  • Scooter
  • Sealing tape, sealing corners and sealing collars
  • Craft knife
Note: To lay tiles, you need a variety of means such as waterproofing, a primer, tile adhesive and tile grout. If possible, use the products of one manufacturer, because they are coordinated with one another.

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How to seal a wet room

  1. Before you apply waterproofing, you should touch up any damage and fill in any cracks and holes with a repair spatula. Once the filler has hardened, sand the repaired areas smooth again with a bit of sandpaper or a sanding machine.
  2. Then clean the surface with a vacuum cleaner and, if it is contaminated, with a suitable cleaner. Above all, grease prevents adhesion and must therefore not remain on the surface.
  3. If it is a highly absorbent surface made of plasterboard, for example, you should first apply a primer. If this is not the case, you can start painting the waterproofing straight away. However, a primer is also recommended for less absorbent substrates. Read our guide "The primer - a sensible measure when laying tiles".
  4. A seal is ready to use, but should be stirred again before use. The best way to do this is with a paddle stick that you put in a drill.
  5. First paint the corners with a brush. Make sure to apply the agent generously so that no areas remain free. Then paint the surfaces with a roller or a brush. This coat of paint should be at least one millimeter thick.
  6. Before the waterproofing has dried, put sealing tape in the corners where the walls meet the floor. With a small piece of wood, a smoothing trowel or some other tool, it can easily be pressed into the corners. For the corners of the room where you need sealing tape horizontally and vertically, you can get sealing corners in hardware stores. They are available in versions for inside and outside corners. You can also lay sealing tape at the points where the shower or bathtub meets the tiles. Its job is to compensate for small movements and thereby prevent cracks in the seal.
  7. There are sealing sleeves for the water inlets and outlets. Alternatively, cut some sealing tape to fit and glue it around the pipes. This work step should also be carried out while the painted sealant is still damp.
  8. All places where you have attached sealing tape or sealing sleeves, paint again with the sealing. Then take a break until the first coat has dried. This usually takes about three hours. However, take into account the information provided by the manufacturer.
  9. After the drying time has expired, coat all surfaces including the sealing tapes, sealing corners and sealing collars a second time with the sealant. This layer should also be at least one millimeter thick so that the seal has a total thickness of at least two millimeters. Let the second coat dry until the following day. After that, you can start laying the tiles right away. An additional primer or the like is not necessary.

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