Vinyl Hardwood: This synthetic material is impervious to penetration or damage due to moisture or humidity. In some cases, low-quality adhesives may come loose in moist environments causing tile curling, but the material itself will not be damaged by water. Because of this, it can be successfully used in bathrooms as well as below-grade basement environments.
Hardwood Floors: Wood is a naturally absorbent material, which will tend to soak up liquids when they come in contact with its surface. If the liquid has a color, this can result in a permanent stain in the wood. Even if it is just water, moisture penetration can cause the growth of mold, mildew, and other unsavory microorganisms. Sealing the floor regularly will help but can not make it proof against floods, common spills, or high levels of humidity. Because of this, hardwood is not considered suitable for below-grade installations, most bathrooms, and some kitchen environments.