The 100% Sustainably Sourced Teak Is naturally resistant to water, mold, and mildew due to its density and high oil content. It has been the wood of choice for hundreds of years for luxury boat builders. This natural resistance has been supplemented by using our proprietary finishes which is a deep penetrating stain with added mold, mildew, and fungus inhibitors. It provides the ability for the Teak to be used outdoors as well as indoors.