Damaged Marble Mosaic Hex... Replace or can it be fixed?

[CMcD]

I was on here 10 years ago when we DIY'd our bathroom in our old house. It turned out amazing so of course I was on here researching now that we're finally renovating our 2nd house.

I splurged on marble hex mosiac tiles for our master bath. Since we planned on installing them ourselves, I learned from here that we needed to seal them after installing, and that they needed to be sealed again after grouting with unsanded grout (because sanded would scratch).

Our reno is a combination of contractor and DIY. But because we now have two kids and we all have busy schedules, we decided to hire out the tile installation since it would get done that much faster. I think you can see where this is going...

Tiles looked beautiful before grouting. But they poo poo'd when we mentined that they needed to be sealed and then used the sanded pre-mixed grout. The floor was half grouted and looked terrible. I pointed out that they needed to get that haze up off the floor and he said not to worry. The whole thing was then grouted and looked terrible. The tiles were cloudy and scratched, and the whole floor felt like sandpaper.

Our contractor agreed that it needed to be fixed or replaced. They were in all day yesterday with a buffing machine of some kind, and now the tiles are shinier, but they are still cloudy and now you can see circular scratches on all the tiles when the light hits.

So I'm wondering if there's any hope for this floor, or if it all needs to be torn up and replaced?

[cx]

Welcome, CMcD. Please change that permanent signature line to a first name for us to use.

Tell us specifically what grout was used.

[CMcD]

It was this grout:

(won't let me post link)
Mapei Flexcolor CQ Premixed Acrylic Grout
Colour is #93 Warm Gray.

I'll try to fix the signature line!

[Kman]

From the Flexcolor CQ Data Sheet:

Some types of sensitive tiles such as glass mosaic or
marble can be permanently stained, scratched, dulled
or damaged when grouting. Always test the grout on a
separate sample area before grouting to determine the
suitability of the tile with the grout color selected.

At this point, I'm not even sure if buffing or polishing will take care of the problem you're having, since you'd also be taking the top layer of grout off. It would have been best to test a square foot or two before starting.

[CMcD]

Is there any kind of solution that can be applied? I'm dreading the thought of busting this out.

[Davy]

I've been told that marble that has been grouted with sanded grout is difficult or maybe impossible to polish out. During polishing, grits of sand are removed from the grout and continue to scratch the surface.

[CMcD]

But is there no acid solution that could be applied in a controlled manner? Would honing powder work? I'm grasping at straws here...

[MAPEI - Technical Service]

Oh my. The good news is that I think the floor may be salvageable. The bad news is that you need to stop damaging it before you can start fixing it. It would have been better had they sealed the tiles first but the tiles themselves shouldn't be stained as Flexcolor CQ doesn't use pigment to color the grout, the color is in the aggregate (which is much bigger and shouldn't soak into tile pores).

First, I would recommend removing the last of the grout haze. That's not going to be a buffing machine discussion or an abrasive discussion. It certainly shouldn't involve anything acidic, acid will eat those tiles up. You need an adhesive/sealer remover like our Heavy Duty Sealer and Coating Stripper:

http://www.mapei.com/public/US/produ...pper_lr_EN.pdf

Once you've gotten the remainder of the grout haze off of the tiles, then let the grout sit for 7 days. I think that some of the reason for the swirls is because they got some of the aggregate from the grout mixed in with the polishing compound. After it has set up as fully as it can, you may be able to polish the marble.

Flexcolor CQ can't sit around for a long time before cleaning, the installer really needs to get on it no later than 10 minutes after installation. It wasn't a bad choice for your floor, but it was a bad result because it wasn't cleaned in a timely fashion. I'm also not completely sold on the color choice, if you do reinstall the floor try a lighter color grout to make the tiles pop more. One last thought, your original tiles aren't polished, they're honed. That means that fully polishing the installed tiles is never going to give the same result as the uninstalled tiles. Good luck, hopefully you can still have a nice result!

[CMcD]

Oh, Dan. Thank you so much!

I will forward this info to my contractor and will update when there's something to report.

[CMcD]

Delighted to report that the cleaner has helped restore the colour of the tiles and no longer has that cloudy appearance.

Now what can we do about the texture? Parts are shiny, parts are matte. Is there a process that doesn't involve sandpaper?

I have made a few queries to local marble restorers who believe the floor can be salvaged and have a few ballpark quotes (less than replacing the floor) but is there something that can be done by our current installer to improve the floor so we can consider this job finished?

Thanks again, so much, for everyone's input!

[MAPEI - Technical Service]

Unfortunately I think you're going to have to buff the matte tiles to be shinier, I'm not aware of any topical product that will make the ones that have been polished more matte. You could try this product first:

http://www.mapei.com/public/US/produ...nish_lr_EN.pdf

It's possible that it will make everything uniform enough to be to your liking, it's probably worth trying prior to spending quite a bit to have the floor completely buffed.

[CMcD]

UPDATE:

Marble refinisher came in yesterday, and in two hours he managed to repair most of the damage. The texture is consistent, and the floor feels smooth instead of like sandpaper. The cost was significantly less than ripping out and replacing the floor, and we are deducting it from the amount owed for the work.

Thanks for all your help!

[Houston Remodeler]

Thanks for the update Corinne