Forget The Vinegar: How To Clean Floor Grout With 2 Simple Ingredients

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You can mop a tile floor all you want, but if the grout is dirty, you'll never get the floor really looking clean. If the grout is the common cementitious type, and not epoxy or polyurethane, surface cleaning with a mop or sponge is futile. Dirt has worked its way deep into the mortar's pores, and you need to scrub it out using a cleaner that will soak in and loosen it. A number of cleaning solutions will work, but if you want a non-toxic option that brightens as it cleans, try a mixture of oxygen bleach and hot water.

The main ingredient in oxygen bleach is sodium percarbonate, which is a combination of washing soda (sodium carbonate) and hydrogen peroxide. It comes as a powder, such as Orchard unscented oxygen bleach powder, and when you mix it with water, it releases free hydrogen peroxide. Peroxide is an excellent oxidizing compound that can penetrate porous materials such as grout and loosen the bonds that hold dirt. Mixing oxygen bleach with hot water instead of cold enhances its cleaning power for the same reason that hot water cleans clothes and dishes better than cold water. 

The combination is non-toxic and produces no noxious fumes. That's good news for people who are sensitive to the strong odors of vinegar or chlorine bleach, which are two other chemicals commonly used to clean grout. Oxygen bleach cleans more gently than these chemicals, and unlike chlorine bleach, it won't affect the natural color of the grout.

If it has been a while since you cleaned your grout, the cleaning solution may need a little time to work before you begin scrubbing. Start by spraying or pouring boiling water onto the grout lines, then follow up by sprinkling powdered oxygen bleach on top. The combination releases free oxygen ions into the grout to lift the dirt. After about 30 to 60 minutes, mix more oxygen bleach with hot water in a bowl and use it to scrub the grout clean. If you don't wait as long before the next cleaning, you may not have to let the mixture sit as long before scrubbing. 

Dirty tiles are often moldy tiles, especially in a moist location like a shower, and oxygen bleach isn't as good a disinfectant as chlorine bleach. However, chlorine bleach won't kill that mold either, because its high surface tension prevents it from soaking into porous materials. The EPA says the best way to deal with mold is to scrub it with soap and water, and as far as lifting dirt is concerned, oxygen bleach is as good as soap. So keep scrubbing until the mold is gone. 

And if you're wondering why we excluded epoxy and polyurethane grouts at the beginning of this article, it's because they aren't porous like cementitious grouts and don't require the same type of deep cleaning. If grout lines are still dirty after regular tile cleaning, you may want to wipe them down with soap and water, but you'll seldom have to scrub them.