Cleaning/cleaning grout mortar - tips?

A question about the grout between the tiles. Even after a year, some of them are still gray, although the grout was brown. Of course, we have cleaned very wet several times and have also tried grout cleaner. Fortunately, in the basement in one corner, it made two tiles spotty rather than really getting the grout "clean." Does anyone have any tips for the grout and possibly also on whether or how to restore the tiles, otherwise I would have to replace two or three again...

What exactly is dirty now? Grout or tile? Normally, both are cleaned after installation, you can also do it yourself with [Zementschleierentferner] (e.g. from Mellerud). Additionally, I would clean the grout with a small steam cleaner, alternatively (if it is normal dirt, like that which can occur in the kitchen or from drooling dogs) with a good lemon cleaner and a toothbrush.

What is dirty now? Grout or tile? Normally, both are cleaned after installation, you can also do it yourself with a cement residue remover (e.g. from Mellerud). Additionally, I would clean the grout with a small steam cleaner, alternatively (if it is normal dirt, like that which can occur in the kitchen or with drooling dogs) with a good lemon cleaner and a toothbrush.

In several places, the grout is still light gray instead of brown, as mentioned, after cleaning multiple times. And in the basement, I tried grout cleaner, vinegar essence, and similar products, which apparently damaged the tiles in that spot.

Hello "Peanuts74". All home remedies whose aqueous solutions are acidic should be used with caution on cement-bound components (here: mineral grouts)! The reason for my advice is that acidic solutions attack the (alkaline) cement stone found in all cement-bound construction chemistry products. As a result, it inevitably loses its strength, slowly wears out of the joint chamber, or crumbles away. There can be no "durability" of the coloring of mineral grouts. Especially not for a highly stressed component such as a floor with ceramic tiles, for example. It is unavoidable that dirt substances with the most diverse compositions settle in the joints or on the grout. And they cannot always be dissolved with acidic agents. Especially fats cannot be dissolved with them at all. The problem that troubles you visually is known from practical experience. There is only one satisfactory solution, which, however, is associated with some effort: renewing the joints. The old grout can be removed with a so-called oscillating saw, which is also known from emergency rooms when cutting old plaster bandages. The new grout should be well pigmented by the manufacturer. This may be somewhat more expensive than a standard cement-grey grout, but in terms of appearance, it maintains the overall impression longer. However, if the original color BROWN has more or less turned into GREY, this indicates that the mixing was not optimally carried out at the time or that the amount of pigment added was minimized. ------------------------ Best regards: KlaRa

Thank you very much in advance for the explanations. However, the joints are only 1-2 years old, so it is unlikely to be a "weathering process." Since the same (I hope I am allowed to say this) PCI mortar, which is naturally brown, was used everywhere, that is probably not the cause. As I said, it seemed more like construction dust in the pores.

I unfortunately can't help you directly, but I heard from our tiler that the gypsum dust is particularly bad for the joints and you end up cleaning yourself "dumb and dumber." But unfortunately, I didn't ask how to possibly get it off again. Maybe for you it is this gypsum dust, which combined with water makes a wonderful mixture that hardly goes away?