How is grouting

Grouting floor tiles professionally

The tile joints have an important job

The joint between tiles is extremely important. One or the other do-it-yourselfer may have seen tile walls or floors on vacation that were tiled without joints, but then in southern countries. There the temperatures are relatively constant all year round and the tiles do not stretch or contract as much as in this country. Even calibrated natural stone tiles and slabs therefore need a joint. However, it can then be narrower. These are also the reasons why flexible grout is always preferable.

Not every grout is equally suitable for every floor tile

The grout to be used also depends on the tiles that have been laid. Flexible and white grout is generally used for numerous natural stone tiles. Many natural stones are translucent, which is why white tile adhesive is also used. Due to the white coloring, the joints appear homogeneous and clean, also because of the white tile adhesive. You should also note that there are also unglazed stoneware tiles that are highly absorbent. Porcelain stoneware tiles that are polished and not impregnated also absorb particles and liquids to a limited extent.

Pay special attention to open-pore floor tiles

With such floor tiles, you should test either on test tiles or a tile area that will no longer be visible later to see whether the tiles can be cleaned properly from the grout or whether it penetrates deep into the tiles. You should also test a cement film cleaner in advance. If the tiles take the mortar (7.79 € at Amazon *) or cleaner deep into them, so that they are difficult or even impossible to clean, you should definitely impregnate these floor tiles before grouting.

Step-by-step instructions for grouting floor tiles

  • Grout
  • Joint silicone
  • water
  • possibly cement film cleaner
  • Mortar pail
  • Drill (€ 48.00 at Amazon *) with agitator
  • Rubber squeegee (water squeegee)
  • alternatively grout board with hard rubber
  • Tile sponge or sponge board
  • Silicone syringe
  • Wooden spatula
  • Grout scraper

1. Preparation for grouting floor tiles

The joints must be absolutely clean. This also means that there is no longer any tile adhesive in the joints. If there is still tile adhesive there, remove it completely with a joint scraper.

2. Mix the grout for floor tiles

In contrast to the grout for wall tiles, the grout for floor tiles can be a little thinner. However, measure the water exactly, especially with colored grout. Otherwise, you may not be able to see a uniform color scheme later.

3. Grouting the floor tiles

Now pour some grout on the floor tiles. However, do not apply too much grout the first time so that you can work in peace and get a feel for the grouting. You can then pour as much grout onto the floor tiles as you can work in in 20 to 30 minutes.

To fill the joints with grout, slide the grout diagonally to the joint with the squeegee. Make sure that there are no cavities, that the grout is applied evenly deep and that the joint height is also evenly high. Otherwise there may be color deviations, especially with colored grout.

4. Wash out the joints in the floor tiles

Now you have to wait a little before you can wash out the joints with the sponge board or tile sponge. When the grout no longer shines and becomes dull, it is usually sufficiently dry. Also wash out the joints diagonally, as this will distribute the grout evenly. Pay attention to an equally high level of flushing out.

Finally, inject the silicone into the expansion joint. Peel it off with a wooden spatula. Finally, smooth out the expansion joint with a moistened finger (so that no silicone sticks to the finger).

5. Cleaning the floor tiles after grouting and flushing

Clean the tiles as soon as possible with a linen or cotton cloth. The more promptly and properly you clean after washing out, the greater the likelihood that you will be able to do without a cement film cleaner. This not only attacks the cement of the grout on the tiles, it also affects the grout in the joints.

There are tile mortars that you can mix very liquid. You can then pour this grout directly into the joint.

Strongly absorbent sub-floors or tiles should be moistened well before grouting. Otherwise, the absorbent substrate and / or the absorbent tiles (polished porcelain stoneware, unglazed earthenware, some natural stones) may remove too much water from the grout. The grout then cannot set properly and dries out too quickly. This in turn can lead to a significantly reduced service life of the grout.

Never grout floor tiles outdoors in direct sunlight, as the grout would also dry out too quickly. You must also protect freshly grouted floor tiles from rain.

Pay attention to the special features in the outdoor area while laying the tiles. Floor tiles on a north side or permanently protected by shade have a narrower joint than tile surfaces on the south side or on surfaces that are regularly sun-drenched.

Water-repellent grout is not waterproof. So in damp rooms (e.g. bathrooms) or in unprotected outdoor areas, you have to protect the subsurface with a suitable barrier under the tiles.

Author: Tom Hess

* Affiliate link to Amazon

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