Does Bleach Kill Mold? Why Experts Say No

Bleach is a strong chemical that can kill mold spores on hard, non-porous surfaces. When you apply it to a tile wall or a glass shower door, the chlorine compounds break down the mold's cell walls, and it dies. The surface dries clean, and you see immediate results.

But on porous materials like drywall, wood, or ceiling tiles, bleach behaves differently. The surface soaks up the liquid, but the active chlorine stays on top. Mold roots, called hyphae, can burrow deep into the material, and bleach never reaches them. Within weeks, the mold regrows in the same spot.

For small areas on hard surfaces, a mix of water and detergent or a commercial mold cleaner can work. Scrub the area, dry it thoroughly, and check for regrowth. For porous materials, the moldy section often needs to be cut out and replaced, especially if it's water-damaged drywall.

If the mold is widespread or you're dealing with water damage, consider calling local water damage pros. They can assess the extent of the problem, remove affected materials, and dry the area properly. For severe cases, a mold professional can test air quality and recommend safe cleanup methods.

• Use a detergent solution for hard surfaces
• Dry the area completely after cleaning
• Cut out and replace porous, moldy materials
• Fix the water source to prevent regrowth
• Wear gloves and a mask when cleaning mold
• See a doctor if you feel unwell from exposure

Act quickly after any water event. Remove wet items, open windows, and use fans to speed drying. The faster you dry the area, the less chance mold has to grow. Keep indoor humidity below 60 percent if possible.

Fix leaks promptly and check for hidden moisture behind walls. If you notice a musty smell or dark spots, address them early. For ongoing moisture issues, a dehumidifier can help. Your insurance company may cover some mold remediation, but policies vary, and your insurer decides what is covered.