There are several trends that have been gaining popularity in the bathroom for the last several years. Natural stone walls and floors, body jets, and steam are just a few of the things that more homeowners have been adding to their bathrooms than ever before. Unfortunately, two of these things don’t work well together, and too many homeowners find out only after everything has been installed.
Natural stone is a porous material, with thousands of tiny holes in its surface, which can absorb moisture. Some stones are extremely porous and will not only absorb the moisture from the fluids they come in contact with, but also any minerals or additives in the water, which can cause discoloration. Other stones, such as Bianco Carrara, may contain high iron content, which can cause rust to appear on the surface of the stone after a prolonged contact with moisture.
In a steam shower, the water particles being produced are small enough to infiltrate nearly all types of natural stone, even those that are less porous and not normally subject to absorption or staining. And while most stone should be sealed prior to grouting and periodically thereafter, even sealers may not be enough to stop the penetration of the water particles into the stone.
Stones that are at particularly high risk of developing problems inside a steam shower include not only Carrara, but also Lagos Azul limestone, which has been known to pit with contact with moisture, and any green marble, which contains high levels of serpentine. Nearly all stones may develop some adverse effect, however, after prolonged usage of the steam shower, including staining and developing mineral deposits.
While stone makes a beautiful addition to any bathroom and most showers, it’s generally a good idea to avoid using it in a steam shower or steam room. Avoiding the use of stone in these areas will help keep your stone shower looking beautiful for many years to come.