Getting the grime out of your grout

DEAR TIM: I've tried cleaning the tile grout on the floors of my home, with little success. The grout just doesn't come clean. The tiles themselves don't look like they used to, even though I'm using those newer pad-cleaner contraptions. What do you recommend? -- Judith P., Forest Park, Ill.

DEAR JUDITH: When I built our previous home, my wife selected a pure-white tile for our kitchen along with a light gray grout. I warned her that the grout would turn black, but my pleas were ignored. To this day, she says it was my idea. As it turns out, the grout did turn nearly black, especially around the refrigerator and sink, no matter how hard I tried to clean it.

The issue became clear one day when I tried to really scrub the grout. Small particles of dirt on the floor dissolved whenever water was spilled on the tile, and this dirty water then soaked into the grout. Spilled liquids such as red wine and cranberry juice just made matters worse.

Regular soaps were powerless, as were the tile and grout cleaning equipment I rented. The pad cleaning tools get up some dirt, but they leave dirt behind if the pads are not changed with great regularity. The smooth pads are powerless to remove dirt from the grout because, in most cases, they never even touch the grout. Look closely at a tile floor, and you'll see that grout is slightly recessed.

I came up with a solution to the grout-cleaning problem about 15 years ago while researching how to seal and clean a deck. I interviewed a chemist who showed me a product I had never heard of: oxygen bleach. This product comes in powder form, and when it's mixed with water, billions of oxygen ions attack dirt and stain molecules, blasting them apart and robbing them of their ability to absorb light. In other words, the stains disappear. Not only does oxygen bleach do this on wood decks, but it also works on anything that's water-washable.

Following the instructions given to me by the chemist, I mixed the powder with hot water and stirred it until it dissolved. I then poured this solution on the tile floor in my kitchen, making sure the grout was completely saturated and covered with the clear solution. Then I walked away for 15 minutes, allowing the oxygen ions to work.

Afterward, I had to add some additional solution where it had soaked into the tile grout. I then used a stiff scrub brush, running it along the grout lines between the tiles. With almost no effort, the grout looked like new.

You can get nearly the same results using chlorine bleach, but there are some disadvantages to that. First and foremost, the fumes are powerful and make many homeowners feel uneasy. Chlorine bleach is so strong that it can ruin the pigments in some colored floor grouts. And if you splash the chlorine bleach on adjacent surfaces such as cabinets or carpeting, it can take the color out of them. It's a tough cleaner to work with.

Once my tile and grout were clean, I discovered a way to keep them looking that way without getting on my knees to scrub again. One day, I decided to use the oxygen bleach powder in the mop water. I mopped the floor like normal, but instead of rinsing it right away, I let the cleaning solution dry.

What I discovered was that when the dirt has not yet soaked into the grout, the solution readily broke it apart and kept the grout perfectly clean. After about 30 minutes of waiting, I would then rinse the floor with clean water. My kitchen floor looked like new every week. The best part is that my wife and I stopped squabbling. It doesn't get much better than having a happy wife and a clean floor!

Tim Carter is a columnist for Tribune Media Services. He can be contacted via his Web site, http://www.askthebuilder.com/printer_submit_question.shtml.