Applying the grout on laid ceramic tiles is the culmination of our ceramic investment. How to do this correctly so that the joint would fulfil the functions entrusted to it and additionally decorate the arranged space? Contrary to appearances, these are crucial and not so obvious issues – this article will answer the most common questions and dispel doubts on this matter.

The subtle contrast between the marble surface of the mosaic and the perfectly matched colour of the joint emphasises the elegance of the interior.

1. What colour of the grout should we choose?

The colour of the grout is of great importance for the aesthetics of the ceramic cladding. In addition to the obvious role of joints – namely, ensuring continuity and lack of gaps on the surface of walls or floors – grout can also play a decorative role. So what colour of the grout should we use? Surely, it depends on the visual effect we would be willing to achieve.

Grouts in the colour most similar to the predominant colour of tiles will best match ceramic collections which objective is to create large, uniform surfaces.

Then the joint visually “hides” behind the exposed ceramic graphics. Grouts in the tonality of tiles should be applied especially in the case of the rectified tiles in the large format, as well as collections imitating the appearance of natural stone or wood.

Thanks to the thin joint in the colour of tiles, we can obtain the effect of a homogeneous floor surface.

If in one interior we plan to apply different colours of tiles, it is worth using grouts in these colours in order to emphasize the beauty of the tiles. Thanks to this treatment, we will avoid the ugly effect of “shredding” the surface. For instance – when we combine white and black wall tiles with a wood-imitating floor in the bathroom, let’s match them perfectly with the colour of the grout.

Three colours of the tiles and three matching colours of the grout for a consistent stylistic effect.

If we want to expose and emphasise the shape or format of the tiles, it will be advisable to choose a joint with a contrasting colour for the base colour of the ceramic. However, we should remember that the contrasting colour has to stay in line with the other elements of the decor and harmoniously complement it.

Marked contrast between the colours of the mosaic and the white grout exposes the beauty of the glass cubes.

A bright grout emphasises and at the same time enhances the shape of clinker “bricks”.

In the case of light floor tiles arranged in places which are exposed to dirt, it is worth considering the choice of joints in a slightly darker colour, maintained in the colour scheme of the tiles. Owing to this practical treatment, we will protect ourselves against labour of Sisyphean of maintaining the joints in impeccable cleanliness.

2. What kind of joints to choose from among those available on the market?

The choice of a joint which meets our expectations and ensures the durability of the cladding has to be made when taking into account the main factors as regards the place of its use and the performance parameters of the products which are confirmed by the relevant documents. What is of utmost importance is the place where the joint should be used – inside or outside the room? In places subject to temperature drop below zero, it is absolutely necessary to use frost-resistant joints.

No less important is the fact whether the grout has the required documents approving it for being used (certificates and ITB certification), and whether the product is covered by the manufacturer’s warranty. If you plan a ceramic cladding on underfloor heating, make sure that the selected grout is also suitable for this application.

3. What should be the width of the joints?

The width of joints is not only an aesthetic matter (although it plays a great role here). These are also the issues related to the physics of ceramics – including their linear expansion.

Therefore, the width of the grout is not arbitrary – it is determined by the instruction of the Building Research Institute.

In the case of assembly of tiles on underfloor heating, as well as on terraces and in places of direct contact with external zones, the width of the grout, depending on the format, should be correspondingly larger.

In the case of rectified tiles of a standard size, a minimum joint width of 2 mm can be used – with simultaneous retaining of larger expansion joints. For outdoor applications and underfloor heating, the width of the joint during the assembly of rectified tiles should also be min. 2 mm.

For rectified tiles, a narrow joint width of 1.5 mm is enough.

4. Where should silicone be used instead of grout?

Grout cannot be assembled anywhere. All corners, joins of horizontal and vertical surfaces (floors and walls), as well as places of contact with sanitary installations, should be filled with special, flexible joints, such as silicone. Of course, the colour of the flexible joint should be exactly the same as the colour of the “ordinary” joint.

5. When the joints should be mounted?

The grouting process can be started not earlier than after the end of the entire day and only after the tiles have been completely fixed to the ground (after hardening of adhesive or cement mortar).

6. How to check if the grout will not cause dirt on the tiles?

Some joints have strong pigments. Before we apply such a joint – especially in a contrasting, much darker colour than the colour of the tiles – it is worth trying to make the test on the tile beforehand. If necessary, you should consider impregnating the joints of the tiles with the joint before grouting or even change the joint to another one.

7. How long should the grout dry up?

Just as bonding the adhesive mortar takes time, we also have to plan the right time for the joint to dry. Premature cleaning of freshly grouted surfaces may cause joints to flush out, as well as scratch the surface of the tiles (because the joints may contain abrasive particles). The drying time of the joint is usually determined by the joint manufacturer, usually it is 24-48 hours.


  1. Grouting is a crucial process due to both aesthetic and utility reasons.
  2. Depending on the desired visual effect, we can focus on displaying or hiding joints.
  3. When choosing the colour of joints, it is worth taking into account the practical issues related to cleaning them.
  4. The joints must have the required certificates, approvals, and admissions to the market as well as the manufacturer’s guarantee.
  5. The width of the joints should be selected for the size of the tiles, as well as the specificity of their assembly (for instance, on floor heating or on the terrace the joint width must be correspondingly greater).
  6. In particular places, flexible joints (for instance, silicone) should be used, in the same colour as the colour of the grout.
  7. Grouting should be initiated after the tiles have been fully set (after a minimum of 24 hours).
  8. Before grouting, it is worth testing for the effect of pigments in the joint on the appearance of the tiles.
  9. Wait until the joints are completely dry before cleaning freshly grouted surfaces.

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Rafał Doleciński
Pasjonat nowości związanych z branżą budowlaną, dla którego nowoczesny design jest równie ważny co dobór odpowiednich materiałów i rozwiązań na drodze do funkcjonalnego wnętrza. Na naszym blogu stara się poruszać tematy nurtujące architektów i podsuwać im pomyły na ciekawe rozwiązania w obiektach wielkopowierzchniowych.