In Alaska we have a constant battle against the elements, especially our winters. As the technology for insulating our homes gets better and better the airflow into our homes becomes less and less. This puts many of us at risk for developing mold, especially those who love long showers, grow a lot of plants, do a lot of cooking, or live in homes with basements in areas with a high water table. So, when mold begins to rear it’s head you might reach for the bleach to put it down, but there are several reasons why that may be a bad idea.
Bleach may only kill the surface mold.
Mold is like a plant in a way: it has roots. In fact the root is the main part of the living mold, and it grows through a substance like drywall or wood, spreading below the surface. The visible part of mold is it’s bloom that appears to release spores into the air which it uses to spread to new surfaces. If you don’t penetrate to the root you may not kill it all and it may just come back later. You may think that if you use enough bleach you can get the spores, blooms, and roots, but that’s not a good idea.
Bleach on a porous substance like drywall will actually feed the mold.
This may seem counter intuitive at first glance, but because of the way bleach works the chlorine in it may be rendered harmless to mold by the time it reaches the roots. So while it doesn’t kill the roots, it does make the drywall or wood damp. And mold loves damp. Even the Clorox company doesn’t recommend using bleach to kill mold because mold often grows on porous surfaces, and neither does OSHA, or the EPA.
Bleach applied to drywall may be toxic.
This seems like an extraordinary claim, but drywall that has had bleach applied to it may release chlorine gas for up to a week. This can make you quite sick. Common symptoms are headaches and sinus issues, along with a feeling of tiredness and general ickyness.
How should you kill mold on porous surfaces?
The EPA Recommendations on removing mold vary from substance to substance, but on drywall they are to clean the surface with a HEPA vacuum that empties into a sealed container and remove the moldy drywall and throw it away. For a small section of mold that means cutting it out and replacing that piece of drywall. I would also recommend spraying the area lightly with a mold retardant like Tea Tree Oil. On non-porous surfaces you will usually find mildew, and Tea Tree Oil is a great remedy for that as well.
The best way to handle mold.
The best way to handle mold is to prevent it from growing in the first place. To do this keep your home dry and well ventilated by running fans when you cook or shower. If you have a home that is naturally damp you may want to get a dehumidifier or a switch for your bathroom fan that automatically cycles on every half hour for a preset time. I also like to take advantage of the warmer winter days (generally when it’s over 30 degrees) to open windows and get some air flow through the home.
If you have any questions feel free to comment here or on my facebook page.