How to Remove Mold from Tile & Grout (Mold)
Wear an N95 mask when scrubbing mold from grout. The scrubbing action releases spores.
What You'll Need
- Spray bottle
- 1/2 cup
- 1
- 1
- 1 pair
- 1
Step-by-Step Method
Wear N95 mask and rubber gloves. Turn on bathroom exhaust fan or open windows.
Spray undiluted 3% hydrogen peroxide on all moldy grout lines. Let sit 10-15 minutes.
Make a paste of baking soda and water. Apply to grout lines and scrub with a grout brush. The baking soda provides abrasion while the peroxide kills mold.
Rinse all surfaces with clean water. Dry with a cloth or run the exhaust fan.
Once completely dry, apply a grout sealer. Sealed grout repels moisture and resists mold far better than unsealed grout.
- Do not mix hydrogen peroxide with vinegar in the same spray bottle (creates peracetic acid)
- Do not use bleach in enclosed bathrooms without extreme ventilation
- Do not skip the grout sealing step if you want long-term results
- If mold grows IN the caulk (black spots that do not scrub off), the caulk must be cut out and replaced. You cannot clean mold out of silicone caulk.
- Squeegee shower walls after every use. This single habit prevents most grout mold.
- Grout sealer needs reapplication every 1-2 years.
Frequently Asked Questions
Hydrogen peroxide is better for most situations. It kills mold effectively, is safer to use in enclosed bathrooms, does not produce harmful fumes, and does not discolor colored grout. Bleach is effective on white grout but can lighten colored grout, produces dangerous fumes in enclosed spaces, and does not penetrate porous grout as well as commonly believed.
Sources & Methodology
Hydrogen peroxide (H2O2) kills mold through oxidation. Its effectiveness on porous surfaces like grout exceeds bleach (sodium hypochlorite) because H2O2 penetrates more deeply into porous materials.
Last reviewed: March 20, 2026