GC Wants to Add New Grout on Top of Old

5 years ago

Our marble hexagon mosaic floor was grouted several weeks ago with Custom sanded grout. It has tiny holes in the grout and it has lots of gaps. It seems to pass the credit card level test, though. The feel of it seems more powdery than I thought it should and it has lots of pin size holes.

Our GC for our new build looked at the tile for the first time since it’s been installed and thinks it just needs more grout. I don’t think that’s the answer, and I thought you should not add new on top of old.

In my opinion, it was a rushed grouting job and so it looks un-smooth. If putting new grout over old is wrong, how do I explain this to our GC.

We need to add countertops so that we can keep moving forward on our build, but I feel we shouldn’t add countertops to vanities until this is resolved. The vanities have legs, so the tile runs under them.

I’m inclined to tell them to let it go because the only way to do the grout right is to remove it, which is too difficult for a mosaic floor in a large bathroom. Maybe they could give us a large discount for the shoddy grout work.

Is there anything else that can be done for a poor grout job to smooth it out? Shouldn’t unsanded grout have been used? The marble is heavily scratched because of the grout :(

Featured Answer

MongoCT

5 years ago

My opinion on the grout?

Adding grout over new grout? It can be done if the new grout is still new. Say within 48, maybe 72 hours. And if the existing grout is solid and stable. Yours does not appear to be. So I'd strike that idea right from the get-go.

When sanded grout, after cure, is powdery and releases grit, and especially when the grout cures and shows pinholes, it's typically due to too much water being used in the mix. The sloppy wet mix gets floated in the joints. During the clean up, because of the excess water, the grout can still be soft and may not firm up well. Because it's not firm, it's easy for grout to incorrectly be raked out of the joints during clean up, resulting in a low joint fill.

As the grout cures, it consumes water in a chemical reaction. If too much water was used in the mix, there can be an excess of water remaining in the grout after hydration is complete. That excess water takes up space in the mix. It'll eventually leave the grout joint via simple evaporation. When it leaves, for lack of better words, it can leave behind a weakened honeycomb-type structure. That can result in pinholes. A weak grout structure. Grout that can be rubbed away with a fingertip, or that abrades when it is rubbed with a sponge.

The other thing is that the grout could simply be old. Past it's prime. Poor turnover at the store where it was purchased. Old grout, or grout that was improperly stored, can absorb atmospheric moisture over a period of time. Hydration can start to occur in the sealed bag itself. When the bag is opened, it typically indicates hydration has occurred by being somewhat clumpy or lumpy, instead of a fine grained powder. Grout that has set off in the bag will not have as strong of a structure as new grout.

And one last thing for now...grout can fail in a joint due to movement. If the tile was set over a tile backer board that was installed over a subfloor, the tile backer board should have been bedded in thinset, then fastened to the subfloor. The thinset fills any voids between the backer board and the subfloor, preventing micro vertical movement between the layers of the floor when loads are placed on the tile. Cured grout is rigid. If the joint it is in moves, the grout can fail.

Okay, one "last" last thing. Sanded versus unsanded. Custom grout, the primary thing CUSTOM cares about when you use their grout is that you honor grout joint width. For joints smaller than 1/8" Custom recommends you use unsanded grout. For joints 1/8" to 1/2", they recommend you use sanded grout.

Grout shrinks as it cures.

If you used unsanded in a wide grout joint, the grout can flake and crack as it shrinks. Wide joints need the bulk sand filler that sanded grouts contain.

Now in your case, if the grout joint size drove you to use sanded grout, then you have to look at the sanded grout installation instructions. Using sanded grout on polished marble? Custom includes a warning that sanded grout may scratch polished stone, glass, etc. They recommend a test board be done to see is sanded is suitable if scratching may be a concern.

If your grout joints are too large to use Custom's unsanded grout, and with Custom warning that sanded grout may not be the best choice for polished marble, it may have been prudent to have pursued another choice of grout altogether.

Okay, a last last last thing. If you want any contact with Custom, feel free to contact Custom's tech support line:

800 272-8786

Have these photos ready to attach to an email. When you get a tech on the line, get his email addy and email him the photos. That way he can see what you are describing. He may say product failure and offer you a rebate. He may say installer error which may give you leverage against your installer. He may say "my goodness, what a beautiful floor" and you simply end the phone call frustrated. But you're frustrated now, so you have nothing to lose.

Good luck getting this remediated.

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Comments (16)

robin0919
5 years ago
Don't pay 'anything' until it's finished in your contract. What's in your contact? That's horrible work!!!!!!
Grace Smith
Original Author
5 years ago
Robin0919 — Do you mind providing me some details on what all is wrong with it. I want to provide some details to our GC.

Also, is it true you can’t just add more grout on top of this?

Thanks!
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dan1888
5 years ago
Inconsistent install gaps and it appears some grout is above the tile level.

From Google-

While it's possible to apply new grout over existing grout, the results are usually less than satisfactory. Since the layer of new grout would be very thin and vary in thickness, it may not adhere well and the old grout could show through. Removing grout from a tile floor is not nearly as difficult as it used to be.
opaone
5 years ago
Is grout material still coming up? I've never seen that happen. In my somewhat limited experience grout is done, wiped down, set, cleaned up, maybe sealed and that's it. No grit. Did they use too little binder or get a bad batch of it?

Is the grout not at an even level below all tiles or is what @dan1888 and I are seeing an optical illusion from how the photos were taken? E.G., in the lower left of both photos the grout appears proud of the tile a bit.
BT
5 years ago
Looks pretty bad, sorry. No grout should be above the tile ... the tile guys appears to forgot to remove the grout.
Grace Smith
Original Author
5 years ago
From what I’ve noticed the grout is below the tile. But I will check to see if it’s above.

The grout seems very gritty, powdery, and has pin point gaps. This week I read that unsanded grout was needed for marble. They also scratched the marble everywhere. Do they need to remove the tile? It seems it will be impossible for someone to remove grout from a large bathroom with this mosaic throughout.

If they have to remove it, I would just go with a regular porcelain tile now that I know how expensive it could be to work with marble.
alex9179
5 years ago
Yes. You use unsanded grout for marble because sanded will scratch it. The pinholes can be caused by too much water in the mix or too much used when wiping the grout away. If you take a box knife to a grout line, does it crumble? Another sign of too much water used.

Check out John Bridge forum for tile expertise. Pin holes, Sanded grout for marble, for example.
Grace Smith
Original Author
5 years ago
MongoCT — Thank you for your detailed explanation.

I had a tile installer look at the work throughout the house and he said he was heartbroken for me and angered that this was done. The poor tile/grout installation is like this throughout the house except for two rooms — which were done by a different crew member.

He said they could have used unsanded since the mosaic spaces are within 1/8” inch and in areas with a bigger gap, they could have adjusted the tile by removing it from the mesh and repositioning it.

We are building a home and the tile work is problematic. I asked our builder to review and inspect before vanities were added, but they didn’t.

Now I have to have vanities removed since they have legs, have the tile redone. My look book also called for Fusion Pro grout in most floors and it wasn’t used — just the regular Custom.

I’m going to ask that we be refunded the cost of the marble, have it removed, and a porcelain reinstalled. I figure that is going to save the GC money by not having them replace it with the same marble.

Is there a way to remove the grout to salvage the marble? I’m gathering that it’s not feasible. This is roughly a 8x15 sized bathroom.

Furthermore, we have a Schlueter linear shower drain and they didn’t use Schleuter wall waterproofing material but RedGard instead. It’s my understanding that voids a Schleutter warranty. I also saw the Schleutter orange rings/disks for the plumbing openings laying in the room, and there’re a big holes where the plumbing is and you can almost see the wall behind.

In the shower niche they used wood the decrease the depth of the niche and installed tile directly over the wood.
MongoCT
5 years ago
"Is there a way to remove the grout to salvage the marble?"

There are ways to remove the grout, but they are tedious. And it's easier with a hard porcelain tile versus a softer marble because of potential damage to the edges of the tile. There are carbide coated cutting blades. Diamond blades. Several different methods and tools. Some powered by elbow grease, some by electricity.

Hex tiles are difficult because there are no long straight grout lines to zip through. There are manual grout saws, but they can be tough with your short grout lines. Once you get a small channel clean, if the grout is flawed structurally, you might even be able to zip it out with a utility knife.

If manual tools won't work, there are powered tools for the job. There are carbide and diamond blades that can be used in multi-tools. Those allow great control during use.

With your short lines of grout, a small diamond coated dremel-type of bit might work too. Diamond coating on the bottom 1/4" or so of the bit. Plunge the diamond in to the grout, hold it at an angle, and let the raw steel shaft of the bit that has no diamond coating ride against the top corner of the tile. Use the bit riding against the tile as a guide. It might work. Might not. The steel may do nothing to the marble, or it may discolor it.

It can be done, but it is tedious.

You tile guy who has eyes on the project and who is able to assess the grout will likely have a favored approach.
alex9179
5 years ago
No waterproofing behind the shower tile means a do-over. If they weren't using Kerdi, I wonder why they didn't apply Redgard to the entire area? Man, I'm sorry but this job looks like trouble.
dan1888
5 years ago
In my opinion you should choose a different installer for the replacement of both the tile and the shower. And don't choose a lesser product to 'save' your GC money. He shouldn't be accommodated because of his failures. Get the quality level you've planned for. That's the reason you're doing this project.
Grace Smith
Original Author
5 years ago
We have a Schleutter linear drain and it’s my understanding they needed to use the Schleutter waterproofing materials on wall and whenever needed. I found two Schleutter disks laying on the deck tub indicating they weren’t used. The walls were waterproofed with RedGard, but a local tile installer said it needed to be done with a Schleutter waterproofed instead.

Is it also your understanding that they needed to have used Schleutter waterproofing throughout for our warranty?
Grace Smith
Original Author
5 years ago
I went to the Schluter website just now. I realize I’ve been misspelling it ;) I saw RedGard in a bag. We did have red stuff painted on the floor. So maybe they did use the Kerdi on the walls and the RedGard was for the floor. Would that be used on the floor? I need to verify they didn’t use Kerdi on the wall. The tile installer who saw the niche that was partially intiled didn’t think they had.
Grace Smith
Original Author
5 years ago
Here are some other photos I took today of the Master Bath with the linear drain.
Grace Smith
Original Author
5 years ago
The grout is much whiter than it should have been. I asked for Custom Rolling Fog, which is a light grey. I think if it whitens it indicates too much water in the grout.

The second photo is disgusting water and trash sitting in the tub. The third photo is of the shower niche. The last photo is the Schluter parts I think they should have used.