If you want tiles, you also need joints – and therefore sooner or later you have to find the right grout. Compared to the tiles themselves, the choice is much less extensive, but the decision is no less important. Read this article to find out what types of grout are available and how to choose the right product for your tile project at home.
The tasks of joints
There are two main reasons why grouting tiles is so important: one visual and one technical. On the one hand, joints set design accents and give wall or floor tiles their final, characteristic appearance. On the other hand, they compensate for movements of the tiles or the substrate, distribute acting forces, prevent the penetration of moisture under the tiles and ensure a hygienically closed surface. In other words: joints take over several central functions for a durable, flawless, robust and hard-wearing tile covering.
However, the decisive factor is to find the right grout for the tiles used, the existing substrate and the degree of stress in the respective area of application. After all, not every grout is equally suitable for the different requirements in terms of durability, use and load of the tiles.
What kind of grout is available?
A large number of different grouts are available in stationary specialist shops, DIY stores or online. Apart from brand and price, these differ primarily in their composition. Depending on the raw material base, jointing mortars are divided into the following categories:
Normal joint mortar / cement joints / joint white
The classic joint mortar – commonly referred to as joint white – consists of fine cement, colour pigments and fillers without a plastic content. Simple joints in tiles or slabs can usually be produced without problems and at a reasonable price with this type of grout.
However, it should be noted that the material does not guarantee water-repellent joints, which means that conventional cement grout is not recommended for tiles in damp or wet rooms . In addition, the grout made of conventional, cement-based tile mortar is relatively rigid and should therefore only be used on flexurally rigid and thus vibration-free substrates.
Flexible joint mortar / Polymer-modified cement joint / Flex joint
In principle, flexible joints are also cement grouts – but enriched with plastics. These make the grout more elastic, so that material movements and surface tensions (e.g. with vibrating substrates or temperature fluctuations) of the tiles can be compensated. In addition, flex joints are usually water-repellent and improve the tile’s flank adhesion.
This means that jointing compounds made of polymer-modified cement can be used in a variety of ways and also for more demanding applications. The areas of application range from wall and floor tiles subject to higher loads to tiles on underfloor heating systems and other problematic substrates to patio tiles or tiles in rooms subject to splashing water or wetness, such as bathrooms or showers.
Rapid jointing mortar
Wherever newly laid tiles need to be reused quickly, fast grouting mortars are often used. These grouts set within a few hours and are then both waterproof and frost-proof (partly suitable for tiles in outdoor areas). In addition, fast-setting grouts can be washed off the tiles earlier and at the same time longer, which is particularly advantageous when grouting large areas. As a rule, this type of grout is mainly used in the commercial sector, less so for private individuals at home.
High strength jointing mortar
If tiles are exposed to heavy loads, high-strength grouts are recommended. The extra-fine microcement jointing compound hardens particularly densely, then exhibits a very high abrasion resistance and is even resistant to weak acids.
Epoxy resin jointing mortar
Where even the best cement grout is no longer sufficient, expoxy resin grouts are used. They are diffusion-tight, resistant to chemicals, easy to clean (important for clean tiles with tile cleaner) and extremely hard-wearing. The solvent-free two-component joint sealants are therefore often used on complicated substrates or in wet areas exposed to water, such as swimming pools, wellness areas, commercial kitchens, laboratories, etc.
However, all these advantages are counterbalanced by disadvantages – first and foremost the elaborate processing and the higher price. But even the completely vapour-tight surface can become a problem if penetrated moisture under the tiles can no longer escape.
Grout colours: What works how?
As mentioned at the beginning, besides the functional benefit, the optical effect of joints should not be disregarded. Especially the colour play of grout – tiles can make a room look completely different. For example, a surface is generally considered to be much more harmonious when tiles and grout are colourful tone on tone, while strong contrasts are often used as a conscious element of interior design.
This should definitely be taken into account when deciding on a suitable grout. However, the colour sorting of many tile manufacturers is unfortunately not always very varied – most articles are offered in various gradations of the classics white and grey, with more and more alternatives being offered online in particular.