Grout is incredibly porous like a giant sponge which means it will absorb any grease grime oils or spills it comes into contact with says leslie reichert green cleaning coach and author of the joy of cleaning and while the culprit may vary from room to room mildew in the bathroom cooking.
Brighten tile grout.
To whiten grout start by spreading a baking soda and water paste on the grout.
Wipe clean with the chamois.
When you wipe the tile 90 of the grout renew will stay on the grout.
Grout provides a sturdy foundation for tile and prevents moisture seepage but it stains easily due to its porous rough texture.
Shake bottle well and remove cap.
Using a tile brush add a thin layer to grout and work in sections.
Press sponge tip up and down along grout line to apply the product.
Then scrub the grout with the supplied brush.
Clean tiled surface and let dry.
Your patience and thoroughness will be fully rewarded because the tile grout will become white as snow.
With tile the difference between dingy and dazzling often comes down to the grout in between.
After you clean the joints and if they are white whiten them better.
Stained grout detracts.
Repeat over entire tiled surface.
Depending on the size of the surface you are working on will determine how long the whole process will take.
It s an easy inexpensive four step process.
Again you can see how i do this in the how to whiten tile grout video link above if it s confusing.
How to whiten tile grout.
If regular bleach lightening won t work the best option that you can pursue is to change the color of your grout by taping off the tile cleaning your grout and applying some grout colorant.
If your tile grout is dirty and stained but still sound consider whitening the grimy grout with colorant.
Leave the cleaner on grout lines for 15 minutes then scrub with a walnut scrubber sponge or tile brush.
Though it s not wise to try to lighten this grout with bleach you do have two other methods you can use to change the color of your grout.
Work in small sections you need to wipe the grout renew off the tile before it dries.
To do this put your gloves on soak a piece of cotton wool in hydrogen peroxide and clean the tile grout.
How to whiten grout that has turned brown.
Sponge on the pretreat solution and let it sit for five minutes.
How to whiten tile grout the easy way.
If there are mildew stains on the grout spray them with equal parts water and white vinegar and let the mixture sit for 5 minutes.
Then use a stiff bristled brush to scrub the paste into the grout before rinsing it off with warm water.