Grout, caulk and mildew

Dark grout lines and black spots in caulk are common in bathrooms. Most can be cleaned; some caulk is better replaced.

Cleaning grout

1. Scrub with a paste of baking soda and water and a stiff brush.
2. For stubborn stains, use a grout cleaner or an oxygen bleach product, following the label.
3. Rinse well and dry.
4. Once clean and dry, apply grout sealer to slow future staining.

Caulk

If mildew has grown into the caulk itself, it usually won't come clean. Cut out the old caulk, clean and dry the joint completely, and apply fresh mildew-resistant silicone caulk.

Prevent it

• Run the exhaust fan during and for 20 to 30 minutes after showers
• Squeegee walls and wipe corners
• Fix leaks promptly

General cleaning information. Read product labels, test in a hidden spot first, and never mix bleach with ammonia or acids. Household Service Masters isn't paid by any product brand.