How Long Should I Use a Post-Leak Dehumidifier

Comprehensive water damage recovery—including prevention of secondary effects such as mold contamination—means extracting all the moisture from the house. This includes the major volume of water you may see pooling on floors, saturating carpets, or flooding the basement. Powerful extractors, high-volume air movers, and pumps are utilized by water damage professionals during this phase. 

However, effective water damage recovery also means drying out the moisture you can't see: seepage under and inside walls, wet building materials like drywall, saturated floor substrate, as well as damaging high water vapor content in the air. To remove those additional sources of water damage, use of high-volume professional dehumidifiers is critical.  

The Professional Approach

Consumer-grade home dehumidifiers typically can't remove more than 5 to 7 gallons of water over a 24-hour period, an amount insufficient for significant damage. Commercial dehumidifiers utilized by water damage professionals extract over 20 gallons of water per day from indoor air and multiple units are typically deployed inside a water-damaged house. The ultra-dry indoor environment created by continuous dehumidification eliminates hidden water from the structure, draws absorbed moisture out of building materials, and keeps indoor humidity continuously low.

How Dry Is Dry Enough?

The question frequently arises about how long a dehumidifier needs to run after water damage. The only responsible answer is: “As long as it takes to dry the house.” There's no set time requirement and duration can range from only 12 hours up to several weeks in very extreme circumstances. The volume of water involved, the extent of the spread inside the structure, the type of construction materials affected and other variables play a role. However, here are a few general guidelines:

  • In average cases, recovery professionals keep dehumidifiers and high-volume fans running continuously from 24 hours up to four days to achieve acceptable dryness. 
  • Moisture meter readings in various parts of the structure are one specification that determines dryness. Generally, moisture readings of 6% to 8% in specified building materials are considered dry.
  • To prevent the activation of mold growth, the indoor relative humidity should be effectively stabilized below 50%.