Tile and grout cleaning:
Every time you clean your tiles, grout gets dirtier. You can notice it on every commercial job (in new restaurants, for example). Just after several weeks from opening a building to the public, one can notice a considerable colour change of grout. It happens much earlier than in a domestic situation, not just because of the amount of foot traffic. Floors in restaurants are washed at very least once a day. This only speeds up the process of grout saturation with dirt. A normal cleaning process can be described as pushing dirt from the tiles into grout lines. Unprotected grout absorbs wastewater with all dissolved dirt and chemicals. There’s no way around it except for sealing of grout.
Some tools are better than others. For regular, standard clean-ups you should use microfibre mops. Those carry just enough moisture to clean. Moreover, a good microfibre cloth catches dirt on contact. It pays to have several mop heads to change them as you go instead of rinsing the same cloth in a bucket of water. Excess of water isn’t a good thing. The more water you use, the more wastewater stays in the grout. It always leads to grout discolouration. In extreme cases, deep stains might start showing through a glazed surface of a tile, if the glaze layer is skinny. Rinsing is as essential as washing. Remember that all chemical cleaning products leave residue (soap scum). The easiest way to rinse the washed surface is to add some vinegar to the water. Let’s say 1/3 a teacup of weak vinegar to half a bucket of water should remove all alkaline residue very fast without causing any acid-use related problems.
Silicone is loved by mould. It gets invaded by mould spores much sooner than grout. To keep the silicone clean you’ll be working with BLEACH. Remember that bleach can damage your coloured grout. Use good old fashioned Janola with a cloth rather than something in a spray bottle. Wet the silicone lines using a sponge or a cloth. Leave the bleach for a minute or so to kill mould spores. Then, rinse bleached areas with clean water. DON’T leave any bleach residue. Even when the grout is white, I still would be careful as there are hundreds of shades of white. Yes, you can make white stains on the white surface if you try hard.
Routine cleaning of stone (sandstone, terracotta, slate)
AVOID ANY ACIDS TO CLEAN STONE!
Indoors and outdoors – a different story. Working outside, you have a chance to hose off tiles with plenty of clean water. Hence, you can use a full bucket of detergents and a scrubbing brush. Saturation of grout with dirty water will occur, but at least you’ve got a chance to rinse a surface properly. Be careful with sandstone not to scratch the surface. Your scrubbing brush shouldn’t be too stiff (God forbid a metal one). Use hot water if you’ve got a chance. Always rinse the tiles with heaps of freshwater after cleaning.
Indoors your cleaning efforts should be limited to the use of microfibre mop as described in “Routine cleaning of tiles”. It helps to have a wet/vac. If you’ve got one, you can allow yourself to use a decent amount of water to rinse. I’m not talking about leaving heaps of water on tens of square meters of tiles and hoping to vacuum the lot before you flood a building. You have to split a job into small, manageable areas that you could rinse and vacuum without flooding a house. That is about all you should be doing with your tiles. Anything beyond that is a profession.