Dried on grout

Question

Has anyone ever left grout on slate tiles before and had trouble getting it off? I have 2 inch slate tiles in the kitchen as a backsplash and have tried grout remover, haze remover and used a dremel tool with brushes.this works but takes forever and the tool overheats quickly..any other ideas?

Kirstin @ Things Made New · Answer

Hi Billie! We just had this same problem in our master bathroom, and we were able to remove the grout easily using an Oxiclean/water mixture (although our tiles aren't slate, they're ceramic). It worked like a charm! Here's the link to my post if you want more information: http://www.hometalk.com/diy/clean/bathroom/removing-dried-on-grout-and-refreshing-grout-lines-2205237

Woodbridge Environmental Tiptophouse.com · Answer

Have you tried a simple safety razor to remove the grout? Also any haze or grout remover needs to sit for a short while to work. It is acid so be careful when using it. If it does not take it off, it might soften it enough to use the razor or something like that.

Billie · Answer

Thank you for the suggestions..I haven't tried the razor but tried scraping with metal putty type knives.I have left the haze remover on for recommended time but still have to use stiff brush because the slate is not smooth and grout got into every possible spot even thou I pre-sealed the tiles as recommended..almost tempted to take it off and start over..It is coming off this way but I can only do small areas at a time because of over heating the dremel tool.. I was just hoping someone might know of something that would work faster

Dalene Anderson Todd · Answer

Hi Billie,
I am so sorry someone didn't tell you that you have to seal your slate or any other natural stone tile before you grout, I have been custom designing and tiling for over 15 yrs.This is a common mistake diyer's make with both tumbled stone and slate, ruined by grout from not sealing with stone sealer before grouting, also if you enhance your stone it needs to be done before grouting. This makes the stone not as porous and grout washes off much easier. Also you should not let the grout set over 15 minutes on stone, so do small areas on backsplash and wash immediately.
I have seen light colored tumbled stone completely color changed from the darker grout without the sealer.
The sealer can also be used after the stone is completely cleaned after grouting and grout has dried and aged for a week or so and this protects the stone and grout from staining. 
If you like the stone/slate when it is wet with a little water that is the color an enhancer will give it usually a darker and more colorful slate or stone, but once you enhance you cannot go back to the lighter color, also once you seal you can't enhance so make sure you know what look you want. 
 
Now unfortunately you face your biggest task trying to make the slate look like slate again......I am not sure what degree the grout has damaged your slate but the only thing that I have ever used and seen results is using plain or apple cider vinegar. It is a mild acid and with the help of vegetable brush and lots of elbow grease you should be able to get the haze off, your kitchen will smell like a pickle factory, lol. You can do this several times if needed. This works very well to take the haze off ceramic and porcelan also and is a good grout cleaner for your tile floors with reg cleaning in your mop water, just make sure you rinse your mop well after using the vinegar as it will make the metal rust and mop deteriorate. Good luck I hope this helps.

Billie · Answer

Thanks Darlene, I did seal all of the slate tiles before grouting and that was why I wasn't to worried about getting all the grout off right away..I have been alternating between the apple cider vinegar and scrubbing with stiff brush and then using my Dremel tool with the brushes to get in the little cracks on the slate,,it is working but very time consuming ..I also notice its easier if the vinegar sits on the tile for a while before I use my elbow grease .
guess I will just keep doing a little at a time
 
 .FYI also notice the vinegar works better than the haze remover !!

Dalene Anderson Todd · Answer

I have been using it for years in tiling and always use it for my final rinse when tiling and tell my customers to use it in there rinse water after mopping.......amazing the many uses of vinegar! I am so sorry about your grout, hopefully it will help others to see your post and know that grout needs to be removed before it dries on the tile. 
 I have actually taken a spray bottle with water and kept the tiles wet as I continue grouting, if I can't stop grouting as you don't want to waste your grout.......sometimes mixing smaller batches of grout can be a solution so you can stop and wash the grout off or have someone come right behind you to rinse. 
 
Have you looked at the steel brush bit attachment you can put in a power drill, maybe that would help????

Dried on grout

Removing Dried-On Grout (and Refreshing Grout Lines)!

Suggested Project Book

What Do You Do With Leftover PVC Pipes? Try These 27 Clever Uses

Other

More

Dried on grout

Removing Dried-On Grout (and Refreshing Grout Lines)!

Suggested Project Book