Does Bleach Kill Mold? The Answer May Surprise You
As a mold remediation professional, I’ve heard this story too many times to count. A person discovers some mold on a basement wall or attic ceiling and goes right for spray bottle filled with chlorine bleach in an effort to remove the mold.
I can see why this might seem like a good idea. You probably use bleach to clean your kitchens and bathrooms and many of us have grown up with the notion that bleach is a powerful chemical agent that cleans up just about anything.
The only problem is when it comes to using bleach to kill mold, it’s not as straight forward as you think and here’s why.
Does Bleach Really Kill Mold?
From a technical stand point, yes, bleach can be effective at killing mold on hard non-porous surfaces.
But there’s a caveat in that statement, did you notice it?
If you have mold growing on a hard non-porous surface like glass, concrete or steel you can use bleach to effectively kill the mold and clean it up.
But I’m not talking about run of the mill mildew you find in your bathroom. I’m talking about mold growing on a wood ceiling or an interior wall – the bad kind of mold.
If you were to use bleach to try to clean this up, you’d actually be making your mold problem worse without even realizing it.
Why You Shouldn’t Use Bleach to Remove Mold
Using bleach in an attempt to remove mold on a porous surface like wood or drywall can have very negative effects.
Because of its chemical composition, bleach is unable to penetrate beyond the surface and get to the root of the mold. So while it may seem you’re cleaning up the mold, you’re actually just removing the visible part you can see – the root of the mold is still there.
I like to use the analogy of pulling weeds. If you just pull the top of a weed off and don’t dig out its root, we both know that weed is just going to grow back in a couple of days.
It’s the same concept with mold. Bleach cannot get to the root of the mold on a porous surface. So while the surface may appear free of mold after using bleach on it, the root of the mold will still be present and growing.
And guess what? After a couple of days you’ll start to see that mold appear once again.
The Effects of Using Bleach on Porous Surfaces
By now you should have a pretty good idea that you shouldn’t use bleach to attempt to kill mold on a porous surface like wood, drywall, insulation, fabric or cardboard.
But just in case you need more convincing, here are some other facts for you to consider:
- OSHA has stated that bleach should not be used in mold remediation.
- Using bleach on wood can actually drive the mold deeper inside the fibers causing more problems for you later.
- Bleach used on drywall can emit chlorine gas for a week or more.
- Because bleach is mostly water, you can actually feed the mold root with what it needs to grow – moisture.
- Bleach is toxic.
To simply sum it up, using bleach on a surface like wood or drywall is going to cause more harm than good.
If Bleach Doesn’t Kill Mold, What Should I Do?
Many of you are reading this because you currently have a mold problem and are looking for a solution to remedy it.
So now that you know you shouldn’t use bleach to remove mold, the natural question is what should you do?
We recommend that if your mold is growing on wood or drywall, that you consult with a mold remediation company first.
Remember, the mold that you see on the surface could be the proverbial tip of the iceberg. You won’t know what’s going on unless you have your mold problem professionally inspected.
It’s our goal help to you identify your mold sources and develop your mold elimination strategy.