How to Clean Grout: The Best Deep Cleaners for Sparkling Tiles

Discover my tried-and-tested tips for sparkling grout! From deep cleaning and removing mold to expert sealing techniques from decades of home renovations, this guide has all the supplies and methods you need for pristine tile surfaces.

Several years ago, after buying our house with a leaky toilet meant we had to install a new floor pronto, I had the blind ambition to install a real marble tile floor with white grout (seen here) in the most-used main floor bathroom.

We often play the guinea pig role around here with our projects, and sometimes we do wonder how things will hold up in time.

We worried the same thing about the peel and stick backsplash in my brother-in-law’s kitchen and bleaching our dining room table. Those projects were both BIG WINS, but we have already had to regrout that tile floor to a more manageable grey color.

While it is high maintenance, it looks almost brand new 8 years later because we reseal it every few years. That also means that all of the grout in the house gets a nice deep clean at the same time and today I am sharing the BEST methods to clean grout deeply and quickly.

What Not To Use

I don’t want to waste anyone’s time, but let’s take a brief look at other grout and tile cleaning methods that I have tested and why I don’t recommend them as best:

• Vinegar plus baking soda. I cannot stand the smell of vinegar and I don’t find that this method works any better than the methods I share below.
• Bleach or anything that will leech color. Many stone tiles cannot have bleach on them, particularly marble. It will actually leech out the color of the tiles.
• Household Bathroom Cleaners. While these work for everyday grime, some of them (Kaboom, Clorox Foam Bathroom Cleaner) also will damage sealants and cause acidic damage long term. I generally avoid chemicals in our home.
• Abrasives like sponges or Magic Erasers. These aren’t effective against mold or stains.
• OxiClean. I tried this and didn’t like the results as much unless I mixed with other chemicals, which can actually be very dangerous. See Oxiclean + Ammonia = POSSIBLY DEADLY.

Supplies and Notes

While I give a few different approaches, and why you would use them, there are still some basics for the supplies apart from the cleaning method. There is a handy printable at the bottom of this post (like a recipe card), so you can use the “jump to tutorial” button at the top to skip down to the instructions.

Grout Brush. Get a brush with stiff bristles (but not metal), a bent handle, and soft, comfortable non-slip grips. While honestly, I use an old dog toothbrush that has all of these traits, I would recommend these OXO cleaning brushes. For our glazed beveled subway tile shower, I also use a larger stiff cleaning brush like this one to make the job faster because the lines are so close together.

Bottle or Spray Bottle. You can use a mist spray bottle with a concentrated stream pattern, but I most prefer a chocolate bottle with a small hole in the tip to control the application.

Baking Soda and Hydrogen Peroxide

I won’t call this an all-natural grout cleaning solution, but it’s cheap, safer, extremely effective in a variety of circumstances, and even kills mold and mildew.

I do use this solution to clean grout between my honed marble tiles, but it’s still important to keep the solution from dwelling on the marble tiles themselves. Marble is very porous and prone to color loss if not sealed well.

I have also used this method to deep clean a mildewy 15-year-old floor in a basement and it worked perfectly.

Best Chemical Grout Cleaner

While hydrogen peroxide and baking soda are indeed environmentally friendly miracle cleaners for grout, some stains like rust or hard water stains may need a different cleaner- say a grout floor that hasn’t been cleaned since a flood in 2010? (true story!)

Zep Grout Cleaner is my go-to reasonably priced professional-strength cleaner and grout brightener that doesn’t contain bleach. Let it sit on the tile grout for a few minutes to minimize scrubbing.

ZEP is moderately acidic (diluted hydrochloric acid), so cleaning gloves and eye protection are required. If you're cleaning a large floor area, work in sections. Wash away with a wet rag and gloves. 

Best Heavy-Duty Grout Cleaner

Clean-eez Grout-eez is a serious grout cleaner for stubborn stains.

I have actually used this one time, and it was to clean some outdoor mortar when nothing else would work for some heavy stains- I tried so many products and this worked to get the heavy stains out without etching the surface like muriatic acid would have done.

Grout-eez is a very powerful acid mixed with a detergent, so keep that in mind it’s not something to use often. It will eventually break down the top layers of your grout surface and will certainly require resealing of the grout.

The Results

Although I have used many methods for different things, I use the peroxide method in my own home because it is highly effective, cheap and safe on sensitive stone like marble tile. This is large format printed porcelain tile that looks like feathered concrete. So, the tile isn’t dirty – it’s designed to look like that.

Here is a closeup of the before and after using the hydrogen peroxide method and after sealing. The grey grout lines look exactly like when it was new, but it’s 8 years old!

Sealing Grout

I use a 10 year grout sealer from the local big box store. I often get asked why I do it if the sealer says “10-year”. Firstly, the bottle says “Up to 10-years”. I would bet that’s a marketing term for if you NEVER EVER walked on, used or cleaned the tile area.

Think about the caulk in your daily shower – many are rated 10 years or more. Has it ever really lasted that long? I’m betting nope, but who is going to complain to DAP about a warranty (or even remember the company much less have a receipt)?

Sealers wear over time from shoes, spills, and even soap and hot water. A good way to test if your sealer is still good is to see how well water beads on it. A great time to test and reseal is just after cleaning the grout to provide that extra protection.