Published May 8, 2010

Q: I've tried cleaning the tile grout on the floors of my home with little success. The grout just doesn't come clean. What do you recommend?

A: When I built our previous home, my wife selected a pure-white tile with a light gray grout for our kitchen. I warned her that the grout would turn black. The grout did turn nearly black, especially around the refrigerator and sink, no matter how hard I cleaned it.

The issue became clear to me when I decided 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 just out of reach of the bristles of the scrub brush. This situation was compounded by spills of liquids such as red wine, cranberry juice, deep-purple grape juice and so forth. Any colored liquid that came into contact with the grout soaked in just like it would a sponge.

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 other dirt behind if the pads are not changed regularly. In most cases, the smooth pads never even touch the grout. Look closely at a tile floor and you'll see that grout is typically below the surface of the tile.

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 mentioned oxygen bleach. This comes in powder form, and when it's mixed with water, billions of oxygen ions attack dirt and stain molecules, blasting them apart. The stains disappear. Not only does oxygen bleach do this on wood decks, it works on anything that's water washable.

Following the chemist's instructions, 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. Then I walked away for 15 minutes, allowing the oxygen ions to work.

After 15 minutes, I had to add some solution where the first application had soaked into the grout. I then used a stiff scrub brush and ran the brush along the grout between the tiles. With little effort, the grout looked like new.

You can get nearly the same results using chlorine bleach, but there are some disadvantages using this chemical. First, the fumes are powerful. The chlorine bleach also can ruin the pigments in some colored floor grouts. If you splash the chlorine bleach on adjacent surfaces like 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 with the oxygen bleach, I discovered a way to keep them looking that way. I decided to use the oxygen bleach powder in the mop water. I mopped the floor as always, but instead of rinsing the floor right away, I let the cleaning solution dry on the floor.

What I discovered is 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, I rinsed the floor with clean, clear water. My kitchen floor looked like new every week.

All of Tim Carter's past columns and videos are available at Distributed By Tribune Media Services


Oxygen bleach

You can buy oxygen bleach at stores and online. You'll find Stain Solver at my website, (type "Stain Solver" in the search box). Other popular brands include Oxy-Boost (, OxiClean ( and Clorox Oxi Magic (, and there are many others. There can be a vast difference in quality as not all of the products have the same amount of active ingredient; some have more filler in them than oxygen bleach. Do your research to find a product you can trust.