Floor Grout Removal

[onewhippedpuppy]

I have some areas of cracking grout in my kitchen, unfortunately the floor warranty from the installer (me) has expired. Any tips on grout removal tools? I’ve seen the Dremel heads, any other power tools that work well for the purpose? It’s a decent sized area and I plan to totally re-grout the room, so I’d prefer to avoid the manual scraper style tools.

[Dantilla]

Grout was cracking in a rental I had. Floor structure flexed too much for tile.
Home Despot has caulk in several colors that matches grout. Perfect match, stays flexible.
Still looked great when I sold it a few years later

[onewhippedpuppy]

I considered using the sanded caulking instead of grout to give me a little more flex, but that might get pricey quick. I’ve used it for repairs over the years and it holds up well.

[Zeke]

FOA, sanded grout is for >1/4" joints. Your question is about removal, so what width joints are we talking about?

I might try an acid wash followed by a neutralizing rinse and smear in new non sanded grout regardless of which you have. If you are bent on removing, just be aware that any rotary tool can go off course and into the tile. So you'd need a guide and a vertical wheel no wider than the joint. I guess that is obvious but I mention it because it will be very difficult to use a rotary tool in 1/8th joints. Most regrout companies weaken with acid and hand remove using hard and soft tools. Or should I say regrout companies use acid on most jobs instead?

Oscillating tools are sometimes used as well and especially handy in corners and hard to reach areas. I will recommend that if you haven't done this to limit your initial work to somewhere that doesn't show or just hire this one out. This is not easy work, far from it. I've done too much for my liking.

[gregpark]

Yes, oscillating tool. I use my Fein multi tool with a .mortar blade. Fast, clean and guaranteed to not damage tile. I hold my vacuum in one hand, the Fein in the other for no dust

[NY65912]

To remove definitely an oscillating tool and carbide blade. I use epoxy grout with fantastic results.

[Alan A]

Originally Posted by NY65912

To remove definitely an oscillating tool and carbide blade. I use epoxy grout with fantastic results.

this. it's almost magical how well it works.

[onewhippedpuppy]

Great thanks guys! I already have a cordless multitool that I bought to undercut door jambs for wood flooring.

Milt, they are large floor tiles, I need to measure but I think 1/4 spacing. There are areas where the grout has fully chipped out so I really need to remove it all.

[Zeke]

That's fine and 1/4, 3/16ths are sure better than trying 1/8th. If it's that loose I think the removal won't be too tough. But I will say this, as long as you get some of the top part broken and recessed you don't have to be anal and get every little piece out.

I don't like using epoxy modified grout as it can be tricky for those that don't do this all the time. I do advise using admix with grout for strength and possibly some more flexibility. Maybe Greg knows more about that. It should bridge over any left over recessed grout left in place. I will say that everything must be free of dirt, and oils, even impregnated floor sealers and polish that could keep the new grout from bonding to any grout left in place, and indeed the tile edges themselves.

I like it very thin so that it runs into and under any voids when first applied. It will tighten up soon enough unless you are actually pouring the grout out of a pitcher. Depending on humidity and temps you will have plenty of working time. Overthinning does weaken the grout but most seem to error on the side of trying to work it too stiff like maybe wall tile grout which has to have some body to it or you'll never get it in the joints, it will keep running out until it reaches a point that it will hang. Then you've lost that much time to work a large area. Mixing up different batches is not recommended unless you measure carefully. The color changes with thicker or thinner mixes. It may be subtle but even sealer won't fix that. Darker colors are more affected than light ones, so take heed.

If I left anything out, Greg will catch it.

[onewhippedpuppy]

Thanks Milt, and good point on the clean surface. The way my wife cleans it has about 10,000 Swiffer treatments on that tile.

[Alan A]

I bought one of these to do mine from HD. I’m a big fan. Especially since I used a hand tool the time before…

https://www.amazon.com/Milwaukee-Electric-MILWAUKEEOPEN-LOK-Diamond-Grout/dp/B0FHH7YQGM/ref=sr_1_8

[look 171]

Make sure your grout isn't soupy. Soupy grout=weak grout and will flick off easy

[gregpark]

Originally Posted by Zeke

If I left anything out, Greg will catch it.

Although I've done ceramic tile I'm not a tile setter. My expertise is carpet, vinyl and wood so I do know how to get rid of tile, grout and thin set ha ha. I do agree on not mixing the grout too soupy, it will be a little on the soft side. A rubber grout trowel forces out the voids well. And I know it's important to use a good sealer after the grout has cured. Impregnator 511 seems to work well

[look 171]

Yes, rubber grout float and push grout in at an angle to the grout joint. It can be drawn back to force grout into the joint fully.

Whip, you grout may have been mixed a bit too wet so its finally starting to fail. Is it set over a slab or raised floor?

[onewhippedpuppy]

It’s a wooden subfloor and I did underpayment prior to laying the tile. I’m not an expert by any means but I’ve laid tile many times before, including five other rooms in this house and have never had an issue. This is definitely the highest traffic room in our house by far, and I laid it 10+ years ago. I also don’t think we sealed it.

Secondary question, any tips on removing a cracked tile mid-floor? I was thinking breaking it out with a hammer in pieces.

[gregpark]

I'd remove the surrounding grout first with your multi tool then tape a rag over just that tile and bust it up. Sharpening a spent multi tool blade on the grinder makes an excellent high speed scraper to clean up the old thin set with no risk to the surrounding tiles

[onewhippedpuppy]

Originally Posted by gregpark

I'd remove the surrounding grout first with your multi tool then tape a rag over just that tile and bust it up. Sharpening a spent multi tool blade on the grinder makes an excellent high speed scraper to clean up the old thin set with no risk to the surrounding tiles

Great, that was my plan.

[look 171]

https://www.lowes.com/pd/MAPEI-KERAFLEX-PLUS-MORTAR-GRAY-44-LB/5013013915

Use this thinset or something similar that allows a bit of flex. Vibration maybe the cause but sometimes, tiles just breaks. If one one is broken, you should be fine. I still say you added too much water to the grout first time around. Good luck