My Son-in-law Tiled His Bathroom Floor And Did Not Wash The Grout Off The Tiles When He Was Done. Consequently, It Hardened. I'm Wondering Whether There's A Solvent For This Hardened Grout. The Tiles Do Not Have A Smooth Surface, But Rather Many Small Depressions And Grooves With The Hardened Grout In Them. Thank-you.

My Son-in-law Tiled His Bathroom Floor And Did Not Wash The Grout Off The Tiles When He Was Done. Consequently, It Hardened. I'm Wondering Whether There's A Solvent For This Hardened Grout. The Tiles Do Not Have A Smooth Surface, But Rather Many Small Depressions And Grooves With The Hardened Grout In Them. Thank-you.
Have you tried scraping a small obscure area with a plastic or even metal paint scraper?

The only thing that will come close to removing groute is muriatic acid. This will work for a very light or haze of groute. Anything thicker and you are out of luck.

I did the same thing when I ceramic tiled my shower walls. It was awful. I don't know what I was thinking letting it sit there like that. My husband bought me a dremel tool with a stone grinding wheel. I had to grind off the dried grout. It took a while but it all came off. He bought it all in a kit for about $40. Hope this helps.

Day 1, a stiff brissel & water. Day 2, I used grout remover (acid) from Lowe's it really didn't do the job, I should have known better, I damm near the killed the dog disoriented could not focus or stand vision blury,poured some water down his throat, put him in the shower washed his feet & shampoed entire body after 2hrs of hell he came out fine... Day 3, mind you this is really thick set grout I left on, rented a electric scruber with a soft polisher pad & used water this helped a lot but not enough. Some friends told me to use clorox or vineger & water .This is white tile outdoor, black grout. Stay tuned.

Try vinegar my husband tried everything a wire brush, a wire brush drill attachment, sulfamic acid, hot water, etc. what has worked best for us it re wetting the grout and scrubbing with water and vinegar. Hope this helps :)

I will try this didn't know it would be so drastic. What I have be doing that is working just taking long and its small glass tile is sanding the grout off with electric sander. It doesn't mar the glass tile and smooths the grout edges around the tile.

I will try this didn't know it would be so drastic. What I have be doing that is working just taking long and its small glass tile is sanding the grout off with electric sander. It doesn't mar the glass tile and smoothes the grout edges around the tile.

This post was 5 years ago. I hope they figured it out by now.