I had the exact issue with black encaustic tiles that were sealed before grouting. They look sand blasted. I was told that grout release should have been used vs sealing them. Most stone installs are done with unsanded grout so they can be polished. If this is the case call a pro stone restore co.

If it is sanded grout it can actually scratch up the sealer making it look blasted.

Before we gave up i was going to try a grout stain which in theory should only stain the grout in the pores but you have white and that would be one delicate job.

Try mixing a vinegar solution or a low muratic acid mix and washing it down with an acrylic brush and then rinsing well. Muratic acid usually will
Work.

Do you have any extra tile left? I recommend testing any chemicals on a leftover piece, before using on the tile. I've used baby wipes to remove grout, but I think your issue is more about getting into all those pores. You may have to resort to getting on your hands and knees and picking out the grout in the pores with a sharp tool. Best of luck

what sealer did you use? it's looks like a glossy coating.

I think it is a good idea to do what you did to a spare tile and then try some remedies.

you may end up have to live with it. sort of has a terrazzo look to it. It doesn't look bad.

He used 511 porous sealer before grout and epoxy grout removed a few days later. It would probably take chiseling the grout out with a needle. I don't think that's realistic. I think we try acid on a sample and see what that does to the honed finish.

I think it looks good buddy, if you can remove it then don't sweat it

Now you have me looking back at the job I did with the encaustic and I used 511. I love 511 but when sanded grout is used it does scratch the sealer.

I see you used epoxy grout, if that is the case it isn't coming out with a brush or just about anything. I would try the grout stain but again the selling points of epoxy grouts are that they are impervious to just about anything so I doubt the stain will color the grout.

You could buy black grout and carefully imbed into the pin holes but you do have white grout. Would it effect the epoxy?

Laticrete is one of the more popular epoxy grouts. If you go on John Bridge Tile form their are plenty of Tile Pro's that use the above every day. I would trust them for a possible solution.

Your installer waited too long to remove the epoxy grout. This product sets up fast and it is recommended to grout a small area and then clean the grout. Grout, clean, grout, clean etc. Time consuming, yes. Most installers treat epoxy grouts as standard grouts when it comes to cleaning and that is a big no no. A grout release would have helped but only if he were to install it properly. Waiting the length of time that he did is your problem. A muriatic acid might help... might. Will be best for you to contact the grout manufacturer and ask them directly what they recommend to help you in your situation.

Also, does this tile have a fire glazed surface? If so, no sealer is required. The Miracle 511 sealer is a penetrating sealer. Penetrating sealers can not penetrate a fire glazed surface -- This product is normally used on natural stone or raw tiles (tile that does not have a fire glazed surface). To me, I think it was a total waste in material cost and time to install plus the cost you were charged to install the sealer.
Not sure if this would fall back on the installer as the salesman who sold you the product should have informed you the right way of installing.

It's a honed basalt limestone. It's not fired. Both the tile seller says they give no guidance on use. They said a seller should probably be used when I pestered them. The installer says it's because of the tile and the grout color. But we had no warning of any risk to look of the original tile.

https://www.missionstonetile.com/Hexagon-8-inch-Basalt-Limestone-Honed-p/m-hex-8-basalt-h.htm

Limestone, gotcha. 511 penetrating sealer is correct but should have been used after grouting. Penetrating sealers penetrate and do not act well as grout releases. Grout release should have been used. Muriatic acid could work to clean the stone but if left for too long on the surface, without proper washing, could change the appearance and texture of the stone. I would still call the manufacturer of the grout to see what they would suggest to remove their product from the surface. Epoxy grouts are a pain in the @ss to clean off natural stone especially when you have pitting.

I apologize it was not epoxy grout. It was regular grout.

This is what I would do, I would use sealer on the grout lines only, applied carefully with a small brush, let it cure and dry, then apply a dark charcoal grout stain and go over with a brush on all the white grout speckles that are on the basalt tile, and see if I can stain and neutralize them to a grey color if not charcoal. Very carefully as to not stain the white grout lines. After that is done, I would go over with a sealer again.

Can you confirm what grout was used during install?

They used sanded grout:

https://www.amazon.com/Custom-221326-PBG38125-Bright-Polyblend/dp/B000R4RBLK

I am unfortunately having the exact same problem. I have the same tile and used white grout and it now has a speckled appearance. Have you tried any of the above suggestions with good results?

Personally, I don't think it looks bad and doing all these machinations could actually make it worse. I think I would live with it and I believe in a few weeks, you won't notice it either. You might be too focused on the details? This is why I am against porous materials in showers and wet areas.

It appears to me with the advent of the trend of contrasting grouts, one has to be very careful and seal the tile even before installation, especially if it is porous natural stone. I wonder if some gentle wire brushing with a soft brush could also work with perhaps diluted vinegar. Some experimenting is in order.

You might try Bostik Blaze if this was an epoxy grout. let sit for 30 mins and scrub w/an antiquing type of bristle brush. The other options are vinegar, rinse w/water and neutralize w/ammonia or baking soda and plenty of rinsing. iF that doesn't work, try Stonetech Restore. I think the OP tried everything else. All natural stone NEEDS to be sealed before grouting. If your tile guys didn't follow the directions of the sealer, then they are the ones that are responsible for replacing it. Do not give them final payment. Let them call in a restoration expert who does stone and see if he can clean it. if not, then the tile crew owes you new tile.

We left it as is. Not much works to get it out. Our tile was sealed before grouting.

Bob, I used some basalt in my shower as well. used both the chair rail edging and a large piece of tile that I cut into strips as a border around the cement tile.

I sealed it once or twice before grouting and didn't have any issues. It actually deepened the black tone.

did you try any of the stone tech acid wash or grout haze removers? If it was epoxy grout, did you try the Bostik Blaze? you could still do it.

Did anyone try any of the ideas listed in this string with successful outcome? I’m now dealing with the same issue. Basalt herringbone shower floor. The installer messed up and used the silver colored wall tile grout on the floor which was supposed to be charcoal colored grout and now I have two problems - silver grout lines and silver speckles all over my basalt floor that won’t come off. I’m thinking of trying Grout Rejuvenator sealing stain in the charcoal color over the tile and grout to see that can prevent having to rip out the floor and redo it.

Courtney

if the installer messed up, then he needs to pay to have it fixed, or redone. have him PAY to bring in a stone restoration expert.

basalt is porous. he didn't seal the tiles first?? basalt always needs to be sealed first prior to grouting.

He says he sealed them twice prior to install. Also, this is actually round#2 of install. Round #1 the floor was not pitched correctly and didn’t drain well - tile installer blamed plumber (who did the custom floor pan) and plumber blamed installer. I was really hoping to avoid install #3. I’m so ready for this project to be over!

you saw him seal the basalt? with what?

that's my bathroom wall that's edged w/the basalt tile (up a few comments) I sealed it myself. no grout stuck to it.

Can you post a pic of what you're talking about ??!

Here are the pictures of the installed floor vs. the uninstalled tile. I didn’t actually see the tiles get sealed, just going by what I was told. Pic of the sealer used is also attached.

I’ve used that sealer. It should have worked.
Tell me something, if you drop water on the tile , what happens to it?

Does the water bead up and sit on top or does it absorb?
Is the ungrouted tile sheet u took a pic of, was that sealed?

Did the tile guy seal the tile after it was set in the shower pan or before?
Sorry for all the questions , to help I need to figure out what was actually done.
I can’t believe he used two coats of sealer on that.
Are you sure he didn’t seal it AFTER he grouted?

Was sealing before even talked about?

Was the tile guy aware this stone is porous?,
You said he grouted with the wrong color.

How did that happen?

Is there another grout that he bought but didn’t use?

Was it written on the contract?

i read somewhere that you should use (non penetrating) surface sealer on basalt instead of penetrating ones. Kind of makes sense given this issue. Not sure how they change the appearance of the stone compared to penetrating sealers.

Hello! Super late to this party, but just found your forum after I had the same thing happen to my Basalt tile. Wish I would have seen this before my husband used white sanded-grout :( We sealed them twice before install too!

If anyone happens to see this, was there any resolution that you found that worked?? I'm pretty devastated as I've already been living with no shower for 3 weeks (using a camp shower in the backyard)! Hoping it can be fixed without removing the tiles and restarting (if that can even be done).

Maddie, what did you seal them with?

have you tried a grout release product?

I used the 511 impregnator sealer. I thought grout release was for before grouting? Will it maybe work after? I'm going to home depot tonight for new tile and my husband planned to just chisel the Basalt ones out and replace with porcelain tile. They seem to be too porous and I'm scared to even keep them now!

Current solution - regrouting with charcoal grout. My husband thinks it looks like just a black wall but I think its much better than the white spots!

Picture shohld be flipped, but this is mid-grouting the charcoal

I do mosaics as a hobby. Once when I sealed the grout on a project, the sealer got on my glass tile and when it dried put a dull film over it. When I went online to find a fix, I read that the only thing that removes that dull film is the same thing that caused it, the sealer itself. The trick was to reapply it and wipe off immediately before it dried. It worked. You might try that on one of the tiles with the grout spots to see if it works.

Thank you all! i actually tried the magic eraser too briefly. It seemed to just foam up and then start taking the grout from between the tiles making it so I’d have to add more grout… and the cycle continued. I also thought about trying the sealer again, but was scared I’d just seal the white specs in more!

For now, the charcoal seems to be working. I need to continue adding some to fully cover the remaining white. This is the first time my husband and I have tiled, so making lots of mistakes! At least we are learning for next time!!

Maddie, You really should have scraped out 2/3rds of the white grout before regrouting. the new grout isn't going to adhere properly, and the white may peek through.

Also, I probably would have done unsanded grout. (did you look at the specs on your tile? what did it recommend?) you have some tiny grout lines. sanded grout has sand particles in them that don't fit well in small joints.

Be careful in the wash portion. if you use too much water to rinse, or the sponge is too wet, you'll dilute the dark grout color and get light spots.

Curious why you didn't go w/the gray grout to start.

BTW, if you do redo, I used this porcelain tile on a clients shower. easier to care for

Hi Beth. You are correct, we should not have used sanded grout, but only figured that out after starting :( Also, the white grout was already halfway gone from the grout lines after we spent time trying to remove the white specs. We also let the white grout dry a full 24 hours before adding the gray. We will be adding another small layer of gray and then sealing everything. Do you think that will be OK?

I have a set of porcelain tiles on the way just in case, but they are backordered, so we are just trying to make these work!

I also wanted to do the gray at the start, but my husband wanted more contrast so convinced me to go with white. Bad decision, but we've learned our lesson now!

no need to do a second layer of grout. you can't layer it. if you got out a good portion of the white and then did gray, it should be good to go

Just had same issue with black basalt tiles and grey grout. Neat white vinegar scrubbbed into pores with a toothbrush seems to be working ! ( No sealant used / needed as tiles glazed)

We just had this installed on our shower floor yesterday. I did not read the small print and didn’t prep it at all. It’s in the shower, ready for grout possibly tomorrow. Should I still attempt to clean and seal it before grout? It’s not clean now, is my concern, because it’s been worked with getting installed.

izzy, wipe it clean w/water and then seal the tops only. going to be difficult tho. don't let the sealer drip down the sides. you need to seal up the top or those tiny holes on the stone will catch the grout.

If you're doing a charcoal color grout, it won't be as bad, but I'd still take a rag and wipe the tops w/sealer. let it sit for a few mins, buff dry. use 511 or Aquamix. if you want to deepen and enrich the color, use a sealer w/color enhancement. always test on a spare piece first

Thanks Beth! I’ve bought the sealer and I’m going to attempt to do that. I wanted some contrast, so I was going to go with a gray grout. I also don’t want it TOO dark seeing as it’s on the shower floor and thought a little lighter would be more forgiving. Hoping it works, thanks again :-)

Hi what the darkest black grout I can get this basalt herringbone ? I have seen charcoal but is there a black? Sanded or non sanded? Any additives to help keep dark?

I sealed it twice before I installed it with 511

We used Charcoal, which looks just like black. Not sure if black exisits. From memory, we used unsanded grout. Its holding up great after 1.5 years! same grout on entire shower.

@Maddie Victoria ok thank you! im going to grout today

sillysquares, I used charcoal on this hex tile

(Mapei Flexcolor CQ. make sure to watch the video on how to do the clean up w/this grout. very LITTLE water during cleanup)

https://www.youtube.com/watch?v=R8SA7d4DLlc
Black

this one is already premixed.

And on this wall, I used the mapei black. the black tile border is basalt, the inside tile is cement

both were sealed prior to grouting but the white portion still got some staining.

if you choose a regular unsanded grout that you mix, measure the water addition very carefully. do not dilute. when you grout and wipe w/a sponge or rag, use very, very little water. the more water used during the clean up, the more likely you will end up w/white spots in your grout

Here's the Keracolor sanded grout in Charcoal

I'd used the charcoal over the black. Or, try this Iron color:

you may get this look

take some sample pieces of the tile and do a quick sample board w/a few colors. see how it looks after it dries.

@Beth H. : thank you so much for all the information!! appreciated :)

I had the same issue with the floor tile. Home Depot has a crystalized grout haze remover that you mix with hot water. I used that with a medium sanding pad. It took most of the grout haze out and didn't effect the tiles.