The answer to 'why is my grout odor' is that grout can develop an unpleasant smell due to a buildup of bacteria, mold, or mildew. This is often caused by moisture, lack of cleaning, or poor ventilation in the area. Symptoms may include a musty, sour, or rotten smell coming from the grout lines.
To address a grout odor, you can try DIY cleaning methods like scrubbing the grout with a mixture of warm water and vinegar or using a grout cleaner. However, if the odor persists or the grout is severely damaged, it's best to call in a professional cleaning service. They have the expertise and equipment to thoroughly clean and sanitize the grout, and can identify and address any underlying issues causing the odor.