Our bathrooms have these small, slab gray tiles that have always looked pretty awful. Recently, I started researching ways to clean the grout (i.e. avoid having to retile), when I looked more closely and saw that it doesn't look like grout at all — it looks like the tile was laid directly onto concrete. The building itself is poured concrete, so it's not entirely surprising. But I can't seem to find any information on what to do with tile that's been laid into concrete. So, I come to you humbly seeking some wisdom: how would you clean and/or deal with the discoloration between tiles laid onto unfinished concrete? Or is the answer that concrete is concrete, and there's nothing we can do besides remove the tile? (Apologies for the zoomed in photo of dirty tile eeeee!)
UPDATE: I decided to give a couple of these suggestions a go. First, I used soft scrub on a portion of the floor. I covered it in goopy, bleachy goodness, let it sit, scrubbed with a toothbrush, let it sit again, and then washed it away. Still the same! Here's a before/during/after: https://imgur.com/a/WxhhBVs. Then, I went for the Mapei Grout Refresh in oyster grey. I followed the instructions and decided the "wet" method was for me. I was wrong! When I tried to clean up the excess, all of the product came up and formed a soup of off-white mess. When I was done cleaning it up, I was pretty much back to where I started. Somebody recommended Zep grout cleaner, and somebody else recommended XLGC — I couldn't find them today, so they were on my list for the next round. But after so much scrubbing and tediousness, I'm starting to understand why so many recommended that it was just time to get new tile! Maybe, if I'm lucky, that's in my future.
anarchyreigns t1_j9rkvew wrote
It’s set with mortar and then grout is applied between the tiles. You can use a product like grout renew to revitalize the old grout, it comes in many colors and last for several years.