For the life of the carpet and the health of the guests, carpeted floors should be deep cleaned at least once a year, more often for high-traffic areas.  Ironically, when improperly cleaned, overwet carpet can have similar adverse effects, deteriorating carpet and creating health issues for guests. 

Over-wetting occurs during the cleaning process when excessive water is used, which soaks through to the lower layers of the rug.  Issues with over-wetting carpet can range from a musty smell (from trapped moisture) to a wicking up of old stains as deep as the backings and pad.  An unpleasant musty smell is a symptom of a deeper problem with mold or mildew in the backing.  Mold, which can trigger respiratory illnesses among guests and staff, can develop within 24 to 36 hours, depending on the humidity, temperature, and dew point levels.  If a musty smell develops soon after cleaning, allow the carpet to completely dry, then re-clean.  If the odor persists, inspect the carpet to determine if it should be replaced.

Exposure of the backing to moisture can lead to discoloration of the carpet and, in some instances, can result in shrinkage and torn carpet or in deterioration and delamination of the backing and padding.

Using a reputable carpet cleaning service or assuring that your carpet techs are well trained can save you thousands of dollars in repair and produce a fresher, healthier environment for your guests.