My shower floor doesn’t look like it did originally. The grout has different shades and looks like it is growing mold on the surface. What is going on with it?
It’s hard to make a determination without seeing this in person, but I have seen shower floors that acted similar to this before. Sometimes the mold is superficial and resides only on the surface of the installation. Most shampoos and soaps contain organic matter, some more than others. When you have organic materials, temperatures, and moisture, you have a great environment for mold to grow. Proper and regular cleaning of showers removes those materials. When used and not cleaned regularly you can end up with a situation like this. Always use neutral PH cleaners approved for cleaning the stone or tile in your shower. And always test them in an inconspicuous area to make sure you will have no adverse reactions. Double check for mold or wet areas outside the shower as well to ensure there are no leaks.
If water has escaped the shower assembly and has reached the wood substructure this can also provide the organic matter needed for mold to grow. If this is the case, you may need to dig into the installation to find the source of mold growth.