Re-grouting tile

[Quickstep192]

It looks like I’m going to need to re-grout my shower floor. There are some black spots that just aren’t coming out.

I’ll need to grind out 144 lf of grout and re-grout. I’m not looking forward to it.

How deep do I need to go? I want to make sure the new grout gets good purchase, but I don’t want to dislodge any tiles. The grout lines are about 1/8” and the 2” x 2” tiles are about 5/16” thick.

Next question: what to use to re-grout?

Last question: Is there a way to get the grout clean that’s not corrosive to the grout?

OK, that wasn’t the last question - Is a MultiMaster still the best tool for this?

 

[Skyman]

That's gonna be a miserable task. Are you sure you don't want to tear it all out and start fresh?

 

[Quickstep192]

Since the shower floor is under the walls, I’d need to re-tile the walls too.

So, no…

 

[rlitman]

I'd recommend TEC Power Grout. I'm not aware of a better tool than the MultiMaster for this job.

 

[Quickstep192]

How deep to I need to grind out the grout?

 

[jkuro]

Something like this may work for you.

https://www.lowes.com/pd/MAPEI-1-Quart-Heavy-duty-Acidic-Cleaner/5014377805?user=shopping&feed=yes-_-0?store=2878&cm_mmc=shp-_-c-_-prd-_-flr-_-ggl-_-PMAX_FLR_000_Priority_Item_Omni-_-5014377805-_-local-_-22872915043-_-&gclsrc=aw.ds&gad_source=1&gad_campaignid=23526945078&gclid=Cj0KCQjw94bTBhDQARIsAN3vv0wUHwPFplC52te1j0Bqh4ShBiaaRQHSgsFOvvyLVaLQ8ovFlVKuuHEaArT2EALw_wcB#no_universal_links