Sodium Hypochlorite, or bleach, is registered to be used as a fungicide only on hard surfaces, such as stainless steel or tile, not wood or drywall. Bleach also has some inherent problems as a fungicide:
- Bleach can lose over half of its strength from the time it is shipped to when it is finally used.
- Bleach does not penetrate wood well.
- Bleach is very corrosive and potentially dangerous for the applicator and those in close proximity.
- Bleach does not usually kill mold but it can slow it down.
- Bleach makes mold clear, so when it grows past the clear part it appears to have “come back”.
Mold should not be treated. Mold should be removed by vacuuming, wiping, or abrasive removal methods. Then if the surface is stained or if you want to make the surface resistant to future mold growth, a sealant, fungicide, or mildewcide can be applied.