Grout Soft & not right color [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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03-06-2007, 04:12 PM
Hi - I put in my non-sanded grout (1/16th" space) about 2 weeks ago, and noticed a couple of things.

First, it is not the right color - it is much lighter than what it was supposed to be.

Second, it seems to be very soft. Rubbing my fingernail into the grout, I can indent it, and if I rub my finger on it fairly hard, a whitish residue will come of onto my finger. (It is the same color that the grout ended up being.)

I was careful to follow the water:mix ratio when I made it up - did I do something wrong, or did I maybe get a bad batch of grout?

Thanks for the help!


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03-06-2007, 04:17 PM
What kind of grout is it?Sometimes you get a bad batch but i can count on one hand the number of times i have,and i've done a LOT of groutin.But it sounds like your grout isn't gonna hold up.If it scratches out with your fingernail ya gotta regrout.

03-06-2007, 05:16 PM
Hey Randy,

Give us some background on your project. What kind of tiles are you grouting, what did you stick them with, and on what? What brand of grout?

Tile Ninja
03-06-2007, 11:45 PM
Here's the thing about grout. It hardens or cures in 3 stages. If any of those stages are interupted than the grout can never reach it's potential density.

In other words grout will turn flaky and lighter than the intended color if there is any kind of motion before it has completed curing.

At that point there is no saving it. You simply have to scratch it all out, fix the cause of the problem (which could be as drastic as re-installing the subfloor) and then re-grout it.

03-07-2007, 12:09 AM
OK - it is a rectified 18" porcelain tile called Travertini (looks like Travertine). I put it on w/ modified thinset, and the grout is Versabond unsanded from Home Depot. It is over cement board w/ Redguard on the walls, and a mud/pvc pan courtesy of the Liberry here.

Does that help?

TILE NINJA: Can you better define "interrupted"? In retrospect, I think I did over-wipe it (mis-read the directions) with a damp sponge, but it did not pull it out of the joints or anything. I kept trying to get the haze off of it w/ the sponge, not realizing that I had to wait for it to set up more & then use the micro-fiber cloth for that. Other than that, and the fact that the mix seemed very dry to me (but this is only my 2nd grout job), everything seemed normal. Since I have 2x2 tile on the floor w/ 1/16" grout, I *really* don't want to have to take it all back out if there is something else to do, or if I am getting paranoid about nothing... the grout does seem pretty soft to me, tho...

Thanks for the help - I look forward to your replies!


03-07-2007, 12:42 AM
What color was the grout supposed to be and how long ago did you buy it?

03-07-2007, 01:20 AM
It was supposed to be "bone", and I bought it about 3 weeks ago...

03-07-2007, 07:05 AM
Well, "Bone" is a common enough color that it's probably not expired on the shelf and three weeks isn't long enough to have expired in your possession. Two other options are that either you used too much water (though you've already said that you measured) or that you might have mixed a small batch from the top of a settled package leaving most of the pigment and cement in the bottom? Do either of these sound plausible?

Tile Ninja
03-07-2007, 11:27 AM
Well rrands1, what I meant by "interupted" was simply anything that could have inhibited the curing proccess. In most cases, the symptoms you've described are a direct result of movement or motion. In other words, if for example this installation was in an upstairs bathroom and your subfloor wasn't secured 100% before you put the tile down, than anytime you walked on the floor, even while grouting, you would be inhibiting the grout from curing properly.

Another thing that would cause the exact same symptoms is too much water on your sponge when forming your grout. Excess water is thinset and grout's worst enemy.

Now since I've had both of these problems in the past, I've learned how to quickly trouble shoot the problem. First of all, look around the entire newly grouted area. Is the grout on the entire floor suffering from these symptoms or is it just an isolated area? Secondly, have someone walk on the area in question, and try to bounce the floor gently. Is the floor flexing at all?

If you find that the floor is flexing at all, than you may need to pull the floor up and fix the subfloor, because the grout is just a symptom of a bigger problem. If you don't want to rip the floor up, and the tiles themselves are down securely, than you can scratch up the grout, and use custom calk. You can find bone calk at any good tile supply store.

If there is no flex whatsoever in the floor, than the problem is MOST LIKELY that you simply used too much water in the forming phaze. That would be the simplest cure...regrout.

03-16-2007, 11:07 AM
OK - I called the grout company to see what they had to say - I explained my problem, and they told me it was effloresence. Well - I was very skeptical - I have seen that before, but nothing like this, but I decided to try what they said anyway, and it worked!

They had me get some sulfamic acid from Home Depot and put that in 1.5 Gal of HOT water and brush it with a nylon brush very well. They said this might take up to 4x of this - I mixed a smaller quantity and did a test area - after the first round, there was a little diference, but after the 2nd round there was a very noticible difference! I am going to give it a 3rd go here in a bit to finish it.

As a note, they said for my next batch of grout to mix it with bottled water to help w/ this problem. I did that for the next batch, but it did not seem to make a difference - I am going to have to scrub it as well. :(

Anyway - I am happy that this helped, and hope someone else can benefit from this info!