We got a call from a homeowner who was worried about mold. They had some water intrusion and they used bleach to wipe down the drywall. Bleach does not kill mold on porous materials, in fact it drives the roots in even deeper. Our direct sample showed an active growth site. Bleach is commonly marketed as a solution for eliminating mold, but it only works against mold on nonporous surfaces, like tiles and sinks. It doesn’t work on porous surfaces, such as wood or drywall.
Bathroom exhaust vent fans need to be cleaned regularly. It's very important to have an exhaust fan that's vented to the outside in every bathroom in your home, and to run it whenever you shower or bathe and for 15-20 minutes afterward to remove excess moisture that can cause mold and mildew to form.