Mildew is a type of fungi that thrives in wet, humid environments. It has the ability to grow on just about any surface, but it can be particularly difficult to clean mildew from grout. Grout is porous and does not hold up well under pressure because it’s made of cement and sand. Mildew needs three things to survive: moisture, oxygen, and food (in this case your grout). Fortunately there are several ways you can get rid of mildew without using harsh chemicals or spending hours scrubbing with bleach!

What is Mildew:

Mildew refers to certain kinds of mold or fungus. The term mildew is often used generically to refer to mold growth, usually with a flat growth habit. Molds include all species of microscopic fungi that grow in the form of multicellular filaments, called hyphae. Molds can thrive on any organic matter, including clothing, leather, paper, and the ceilings, walls and floors of homes with moisture management problems.

Mildew health problems:

When moisture and humidity levels are high, the chances of mold growth indoors increases. Some people develop health complaints as a result; these health issues may include breathing difficulties, such as nasal stuffiness or dry throat (which might be accompanied by wheezing), eye irritation like itching, tearing or burning eyes. Other symptoms that you might experience due to mildew exposure include difficulty concentrating and headaches.

What should I use to clean mildew off grout?

Using bleach can make matters worse because it will kill the good bacteria in your home along with the bad! It’s also highly toxic for humans and other living things so we don’t recommend using chemical products on grout either- especially if there is any chance that you have a health issue.

Home Remedy

How to remove mildew from grout using vinegar:

You will need two ingredients for this method – white distilled or apple cider vinegar and baking soda. Vinegar is acidic, so it has the ability to kill off mold spores. Baking soda helps neutralize odors as well as removing stains on porous surfaces like your grout lines! Follow these steps:

– Mix one cup of vinegar with one tablespoon of baking soda in a spray bottle

– Spray the mixture onto the surface where mildew is growing (it may take more than one application)    – Leave the solution on overnight if possible then wipe down with water in the morning    According to health experts at, you can also use hydrogen peroxide and water to remove mildew from grout:

– Make a solution of one part hydrogen peroxide and two parts water

– Spray the mixture onto your grout lines for an hour or overnight if possible then wipe down with clean water in the morning  – Repeat as necessary until all traces of mildew are gone

We hope that these tips have given you some ideas on how to remove mildew from your home! If health issues persist after removing mildew, it would be best if you consult with a health professional immediately. For more information about cleaning mold check out our article titled ” Mold Cleanup “.          How to Clean Mildew From Grout.

Professional Solution:

Rarefier from K.O.R. Stone Care Products is a non-toxic, eco-friendly solution to mildew. It is safe for grout and other porous surfaces like stone or wood. Our team can help you get rid of mildew on your flooring without the health risks that come with bleach! For more information contact us at  706.888.8832

How does Rarefier work?

Rarefier carries oxygen into the pores in your stone/grout by creating microbubbles when added to water. The bubbles burst open on surface areas where mildew has grown allowing it to be fully penetrated by oxygen within 24 hours resulting in 99% kill rate of all harmful organisms.

How to Apply Rarefier Cleaner Click Here

remove mildew from grout


Mold, mildew and fungus can be a real nightmare. It can ruin your grout and tiles if you don’t take care of it fast enough.

You’ve tried all sorts of products to get rid of the mold on your bathroom walls or the algae on your patio flooring but nothing seems to work!


KOR Rarefier Cleaner is an eco-friendly solution that will help you eliminate these unwanted nuisances from your home or office in no time at all. This safe cleaner uses powerful enzymes that dig deep into the pores of porous surfaces such as brick, stone, concrete and grout. It then breaks down any organic residues and lifts them away without harming the surface itself! Say goodbye to scrubbing for hours with harsh cleaners only to see little results. Our product’s patented formula is designed specifically for cleaning hard surfaces so you’ll be left with clean lines and sparkling finishes in just one application! Each bottle contains 32 fluid ounces.