Polished Marble Shower Tiles Now Dull
We had 10" square marble shower tiles installed on the walls of our master shower 5 years ago. The color is a deep rust with white veins. The lower part of the shower has become quite dull over time, even though I have used a marble product that is for cleaning and sealing. There is no soap scum.
Is this globalized etching and would your Marble Polishing Paste restore the shine (so that the lower tiles will look like the upper tiles still do)?
Yes, based on your description you most likely have globalized etching and the ETCH REMOVER / Marble polishing paste
will do the trick for you restoring the color and shine.
But just to clarify, this product is for use on shiny "polished" marble, travertine and limestone.... not honed or tumbled. My first thought
was soap scum and even possibly hard water deposits because this is a common pattern for it, but if you feel you've conclusively ruled those out, then it has to be etching. But it is not likely
that the marble etching was caused by the marble cleaning product you used or else all of the marble shower tiles would be etched... unless you only clean the bottom half, which I doubt. Two other possibilities are...
1. A product you regularly use in the shower is acidic and gets on the walls when rinsing, etc. just like soap scum does.
2. The water itself is acidic, which is the case with some city (and I imagine well) water supplies.
In either case you would not see etching right away. It would take a long time, which fits with your description. Another consideration
is the pattern of etching you see. It would be very unusual for the etching to be completely even all the way around.
Like soap scum, you'd expect to see more extensive and/or more severe damage in areas that have the greatest exposure to the shower water.
Of course, it is possible that with enough time the etching could become uniform enough that you'd have a hard time noticing a pattern.
You can experiment with products (dripping some on a tile) to see which (if any) etch, but if it's the water you'll likely just have to periodically re-polish the lower tiles with the Etch Remover / Marble Polishing Paste.