Black Marks Are Mold?
Dark grout is not always caused simply by dirt. In consistently damp environments, especially bathrooms and poorly ventilated areas, black or dark spotting may sometimes be associated with mold or mildew.
Cleaning the visible discoloration is useful, but preventing excessive moisture is equally important. Improve ventilation,
repair leaks, dry wet surfaces, and address persistent dampness whenever possible.
If discoloration repeatedly returns despite cleaning, or if grout is cracked, deteriorating, or permanently stained, cleaning alone may not solve the problem. Damaged grout may need to be repaired or replaced.
When a Commercial Grout Cleaner May Be Better
Homemade cleaning methods are useful for ordinary household grime, but very old stains may require a dedicated grout cleaner. Choose a product that is specifically compatible with your tile and grout type and follow the label directions carefully.
Avoid usinghighly abrasive tools such as metal brushes, as they can
