Q. We have a tumbled travertine (unsealed) stone floor in our shower. I really need to know how to deep clean this floor, as it has gotten bad - a bit scummy, mildewy, and moldy. How should I clean my shower floor? Can you help?

A. Keeping your shower floor clean can be a challenge. Mineral deposits, body oils, skin cells, and soap and shampoo products can build up over time. Heavy duty shower cleaners may be effective for removing stubborn contaminants, but many of these harsh cleaners can harm your stone. Here are some tips to help you identify and remove contaminants.

Avoid acidic cleaners. Limestone is acid-sensitive. Travertine is a type of limestone. Grout cleaners, vinegar, and other acidic cleaners can damage the surface of your travertine. If you are unsure whether a product is acidic, read the label carefully. Most acidic products will have a warning label to avoid use on marble and limestone. 

Identify the type of problem you are dealing with. Hard water deposits, usually caused by a build-up of minerals in your water, are generally white and hard to remove. They may start as a white film, but over time, deposits can build up into a crusty layer. Soap scum build-up can accumulate on your shower floor, as well. It has an unsightly gummy appearance and can cause the floor to be slippery. Mold and mildew are biological growths. Mold may be black, green, or some other color. The texture may be raised, and it can look fuzzy. Mildew lays flat and may have a blotchy white or gray appearance. Over time, mold and mildew can grow and expand, causing the surface of the stone to spall. Other problems include permanent staining, harboring bacteria, and producing spores that can enter the air and cause respiratory problems. Once you have identified the problem, use the appropriate cleaning products and solutions, as follows.

To remove contaminants, apply the appropriate cleaning solution and scrub with a nylon scrub brush. For hard water deposits, use a mild detergent or pH-neutral cleaner, available from most home centers and grocery stores. If this doesn’t work, you will need to get more aggressive. Try a heavy-duty stone cleaner or alkaline cleaner. For soap scum build-up, use an alkaline soap scum remover that is safe for marble and limestone. Check the label carefully. To remove mold and mildew, use a mild bleach solution. Good alternatives to bleach are a commercial peroxide or OxiClean™ products. OxiClean™ products take a while to work, so you may have to allow the cleaner dwell for several hours to be effective. After cleaning your shower floor with heavy-duty cleaners, alkaline cleaners, or any product containing bleach, be sure to thoroughly rinse and clean the area with pH-neutral cleaner to restore the pH balance and avoid damage to the stone. 

The best way to avoid any build-up is to clean the shower floor on a regular basis. After showering, rinse the floor with clean, hot water, then squeegee the excess water. 

A good quality stone impregnator can help, but it’s best to consult a professional, as sealing stone in wet environments could result in other issues. Avoid topical coatings, which can make the floor slippery.

If the contaminants on your shower floor are especially stubborn, ask your stone restoration technician to professionally clean and sanitize your shower. A professional can use high quality cleaning solutions and methods to achieve the best possible results. If you do not already have a professional stone restoration contractor, contact us. We can check if a Certified SurpHaces PRO Partner services your area.