DIY Floor Grout Color Problems
Floor Grout Problems - The Wrong Color
DEAR TIM: I made a mistake and discovered your detailed floor grouting video series a bit too late. I should have watched them before I started my job, but what’s done is done. Five hours ago, I grouted my bathroom and the color of the grout is not what I want it to be. It doesn’t match the color stripe on the bag. I think I see efflorescence on the edges of the grout where the color of the grout is whitish. What did I do wrong? What can I do to get the grout to the color I want? How can you get a perfect color match when doing tile grout? Michael Bernier, Quebec, Canada
You may get into a bit of trouble like Michael did from time to time. When my son-in-law was dating my daughter in college, he was working part-time for me helping me on my AsktheBuilder.com website. After a few days he said, “Mr. Carter, you’re in the life-preserver business. I can see from all your emails that people come to you in need of help because they failed to take the time to discover exactly what to do before they put a tool in their hands.”
Sadly, not much has changed in thirteen years and it’s gotten worse. You may think you know what you’re doing, or you may start a project after receiving some bad advice from any number of sources. Only after your DIY ship starts to sink, do you then flail about in the water shouting for “HELP”. Sometimes the fix is easy. Sometimes you have to rip things out and start over.
How long before the true grout color shows?
Michael provided some very interesting clues. The biggest one is he reached out to me only after five hours. You may not think that’s important, but it is. I’d venture to say his wide and deep grout lines have yet to fully dry. He points out that he sees a “whitish” color on the edges of the grout. That’s another very important clue.
Wet grout almost always appears darker than it is dry. It can take new grout 24, or even 48, hours before it’s completely dry. It depends on the humidity and temperature in the room where the grout is installed.
Is the color stripe on the grout bag the exact color?
While grout manufacturers no doubt try to get the color stripe on the bags to be a true representation of the color of the dried grout, you can’t count on that. If you use pure water to mix the grout and don’t mix in any liquid additives, you can almost always count on the installed dry grout to look almost identical to the color of the grout when it comes out of the bag. Your job is to test this before you start to add grout between the tiles.
Michael should have taken some of the grout, mixed up a small amount, and used it to grout in between several small cut scraps of tile that he had leftover from the installation. He should have let the grout dry for three days and then compare it to the color of the grout as it comes out of the bag. You should do the same or you should request your tile contractor to do this so you know the grout color will be what you want.
The efflorescence that Michael is referring to is not efflorescence. It’s simply the colored cement paste of the grout fully dry where it’s maybe as thin as a hair on your head. You often see this same grout haze on the surface of the tile an hour or so after you’ve finished grouting. In many cases, this fine grout residue is almost a perfect match for the dry color of the grout.
Do liquid grout additives work?
Be aware that liquid grout additives can drastically alter the color of the installed grout. I found this out the hard way many years ago. I followed the instructions to the letter when using the additives, I used virtually no water to strike the joints and even still, my grout dried very blotchy. My wife was very upset and it took me many many hours on my hands and knees using an artist’s brush and special penetrating oil-based grout stain to get the grout to look a uniform color. Never again did I use a grout additive.
If you discover you’re in a mess like Michael, the first thing to do is relax. Wait a few days and see what color the grout is when it’s fully dry. I’m thinking Michael is going to be pleasantly surprised. He needs to pour some of the unmixed grout from the bag onto the floor next to a grout line and compare the color. My guess is it’s going to be very very close if not a perfect match.
What if I need to change the color of the grout?
If you do need to change the color of the grout, you can purchase penetrating stains that are nearly identical to wood stains. You have to slowly and carefully apply these to the grout lines and not get any on the tile. It can be a wretched process.
The issue is it’s almost impossible to go from a dark grout to a light color with these stains. You can always go from lighter grout to darker with no effort. Beware products that say they’re grout stain, when in fact they’re simply thinned paint. You don’t want a product that forms a film on top of the grout. You want a true penetrating stain that soaks into the grout matrix.
If you want to see the correct way to grout a tile floor ensuring the color turns out the way you want it, I urge you to watch the four tile-grouting videos on my website.
The first video in this series is shown below.