Using Bleach to Remove Mold

January 13, 2026 | Videos & Tips
using bleach to remove mold

Cuyahoga, Ohio Mold Removal | Does Bleach Work to Remove Mold?

Good News! Bleach can kill virtually every species of indoor mold that it comes into contact with.

That sounds like every homeowner’s dream come true, doesn’t it? Why pay for an expensive mold remediation when you can run down to the nearest grocery store and pick up a gallon of “super mold killer”, better known as chlorine bleach?

Why doesn’t this idea work very well? The answer is that bleach will only kill mold that it comes into contact with. If you try to use chlorine bleach on a porous material, bleach will only affect the surface mold. The chlorine in chlorine bleach, sodium hypochlorite, does not, and will not penetrate into porous materials.

Bleach Works in Removing Mold from Non-Porous Surfaces

If you intend to remove surface mold from non-porous surfaces, such as shower walls, counter tops, or painted surfaces, you can use the following ratios. However, keep in mind that if the conditions in your home are creating mold in areas you can see, it is likely to also be on porous material or areas that are not easily seen (behind walls, inside cabinets, under the attic insulation.)


Bleach to Water Ratio for Mold:

• For small areas: Mix 1/3 cup of bleach with 1 gallon of water.

• For large areas: Mix 1 cup of bleach with 3 gallons of water.

Bleach to Water Ratio for large area mold removal of porous materials. Cuyahoga, Ohio Mold Removal
For Non-Porous Surfaces

Chlorine is scientifically designed to NOT penetrate Porous Surfaces

The component in bleach that will penetrate however, and provide the one thing that mold needs to thrive, is water. Bleach is 94-95% water.

Many so-called experts recommend you use a solution of bleach and water to kill mold. They recommend a ratio of 1 part bleach to 10 parts water (roughly one cup of bleach to one gallon of water). So, let’s see if this makes sense. You take a product that is already 95% water, and then you mix it with 10 times as much water. Then it’s expected it to be a mold killer on porous materials.

Cuyahoga, Ohio Mold Removal in Attic
Bleach Does Not Work On Porous Materials

Bleach Is For Disinfecting – Not Mold Remediation

Bleach is a great disinfectant. It is not a great mold remover. Bleach will kill on the surface, but it will not kill the roots. The water in the bleach will then penetrate to the roots. You do know that the best way to keep a living thing alive is to give it plenty of water, don’t you? Mold remediation for porous materials will require professional mold remediation in Cuyahoga, Ohio.

“Gee, why does that mold keep coming back?”

When you have a mold problem, don’t rely on just anyone. If you are in the Cleveland Ohio area, call a true professional, Mold & Air Duct Pros, 440-249-4779. We’ll solve your mold problem by doing it right the first time. We Guarantee It!

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