sealing efflorescence

[TileTyler]

okay, here's my situation. i finished grouting my glazed ceramic kitchen floor on Monday. i cleaned the tile haze on tuesday and again on wed. i noticed efflorescence on the polyblend "sahara sand" sanded grout. i was going to get aquamix grout haze remover, but my wife now likes the lighter color of the grout against the tile. i have a gallon of impregnator 511 sealer for the 400 sq. ft. floor. will there be a problem sealing the grout, efflorescence and all? is a gallon enough (1/8" spacers)? and if i had to clean the groutlines, is there a cleaner i could use now (some of the products suggest to wait 10 days for the grout to cure)? the wife wants me to seal on friday and have our kitchen in working order by saturday. :bang: any advice?

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[Shaughnn]

Hello Tyler,
If you both like the grout color as it is and the grout doesn't discolor a dry towel with vigorous scrubbing , then you are good to go. "Efflorescence" doesn't happen as immediately as this. It is caused by the migration of salts through masonry units with water or vapor as a vehicle. What's more likely to have happened is that either too much water was used during the grouting process or the curing time has been accelerated, both causing the grout color to develope much more pale than intended.
Yours is a common misunderstanding as many people use "efflorescence" inappropriately. But they are two very different animals and have entirely different remedies.
Best of luck and enjoy your kitchen on Saturday,
Shaughnn

[DonB]

Hi Shaughnn,

That... is very interesting. A similar thing just happened to me and my knee-jerk assumption was efflorescense since I waited only 12 hours after cutting out the previous ruined grout job.

I used Delorean Gray but it turned out Arctic Ice. However, I spread the excess grout outside in two places. One, a thin skim coat over a slab crack patch previously filled with excess white Hydroment PM and another little bit that was thickly plugged into an area of rough, concrete truck washout in the yard. Both of these areas are the proper color.

As you saw in my thread in the other forum, I filled my tile joints full to the top with grout and only worked them after hardening with a margin trowel and barely touched them with a damp dry sponge. It's definitely not a case of overworking the material or too much water. It was mixed stiff and allowed to slake.

In testing it now, the only transfer I get from rubbing with a dry, dark towel is towel fuzz and scratching some out reveals the same color through and through so it can't be efflorescense.

Like Tyler, my wife is very happy with both the incorrect color and the grouting style I used. I'm not happy because I don't understand what happened here. The only thing I can think of is I started with water in the bucket that came from the well, before treatment for high acid (5.0 pH) and before treatment for hardness. But then again, the color was affected only within the tile installation. Do you have any ideas?

Don

[Shaughnn]

Hello Don,
The way I understand the relationship between grout's curing time and it's final color, I suppose that a dry CBU that wicked the moisture out of the grout, and prematurely ending the curing process, might be your culprit. The sites where you applied the grout elsewhere were likely less "bone dry" than the CBU, and so their effect on the curing process was minimal.
But that's my best guess and I didn't go to school for none of it, :)
Shaughnn

[DonB]

I can't see it Shaughnn. Here's why. I was concerned about the absorptive capabilities of this slab because it was troweled so hard and smooth. Under similar ambient conditions of around 75° and 50% inside and out, I tested. A 3" puddle of water poured on the brushed concrete garage slab soaks in within 8 minutes. The same diameter of puddle poured on this slick floor requires 2 hours before there's no visible water remaining on the surface. Additionally, this floor has been repeatedly wetted from spraying for glue removal, my attempts at wet grinding a hump, washing and mopping up several times to get the grinding dust, washing again immediately before spreading mud, setting the tile and the ill-fated grout job of the day before. I also did some light spraying in advance of laying down the grout and began spraying the floor within an hour or so after I got it cleaned up and have sprayed it several times since then. I do this to the point there is standing water on all the tiles.

If dryness is the culprit it's has to be because I mixed the grout too stiff. Since it wasn't difficult to work and pack in, I really can't see that as a realistic possibility either.

I dunno and it puzzles me a lot. I just wish I knew because I don't want this to happen on the more important floors. I've never seen anything like it before but my experience is limited and spread out over 20-something years. In other words, every time I tile it's a whole new world because I've had time to forget everything I learned before :)

Don

[Shaughnn]

Oh Don. I hadn't recalled that your tile was installed over a slab. I incorrectly presumed it was over CBU. Well, that throws that supposition completely out the window, doens't it? :)
I guess I just don't know why, then. :)
Shaughnn

[DonB]

Welp, I guess that settles it, huh? :yeah:

Since the wife likes the color and the grout is hard as a rock, would you simply suggest damp curing it for another day or two and then seal it?

Thanks Shaughnn.

Don