Terrazzo floors, while beautiful to behold, can be difficult to maintain. Aside from the normal wear that comes with aging, there are several major causes of staining on terrazzo flooring, which can baffle the homeowner's conventional attempts at cleaning. One of the most common of these trouble stains is rust.
Terrazzo flooring in the home is most commonly found in the kitchen or on the patio. Unfortunately, these are the places where the metal meets the floor. A refrigerator, which condenses regularly, is a major source of rust stain on terrazzo flooring, as is most patio furniture. In these common cases, prevention is better than a cure. Capping the metal bottoms of your appliances and furniture with rubber fittings can save you time and money and increase the longevity of your products, but this is not 100 percent effective, and if there are stains already, there are a few methods of clearing them.
If the rust stains in question are not severe, it may be possible to remove them with simple hydrogen peroxide and ammonia. Hydrogen peroxide can be found in most drug stores and is often touted as a stain remover for carpets and clothing. Ammonia is available at most supermarkets. If you are working indoors, make sure to properly ventilate the area, as both chemicals can be hazardous when inhaled in a confined space. Also, ammonia can burn the skin, so make sure to wear gloves. To clean, simply soak an absorbent cloth in peroxide and press it directly over the affected area. Next, soak another cloth with ammonia and press it on top of the peroxide cloth. Leave the cloths on the stain for about an hour, and then remove them. Wipe the terrazzo. If rust remains, repeat the process.
If hydrogen peroxide and ammonia are no help, or the stain covers a large area and cloths are impractical, try a cleansing paste used as a poultice. This method takes longer and requires you to close off the affected area from traffic for a time. Create the poultice by mixing one part of sodium citrate with six parts of water; add six parts of glycerin and one to two parts of calcium carbonate, mixing until the mixture is thick enough to stick to the surface of the affected area. Apply this mix generously to the affected area and leave it on for three to five days. Remove it with any household degreasing floor cleaner. If stains remain, repeat the process.
If the above methods do not remove the rust stains from your terrazzo floor, you may need to strip, seal and wax your floor. This should be used as a last resort as it can be expensive and time consuming. This process should be used on the entire floor, not only the affected area. Stripping only the affected area of your floor can leave the visual quality of your seal looking uneven or discolored.
Strip the floor using any conventional floor stripper. Once the floor is stripped, use a hydrogen peroxide soaked cloth to bleach any remaining rust stains and a peroxide soaked Q-Tip for the hard to reach areas. Finally, reseal and wax by mopping four coats of acrylic finish onto the terrazzo floor, at three hour intervals.