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How do I assess the water damage to the gypsum board?


When gypsum board is exposed to elevated levels of moisture, an assessment of the potential damage to the gypsum board must be made as to whether board exposed to these conditions must be replaced. Gypsum board may experience limited intermittent exposure to moisture from a variety of sources, such as improper storage, construction or design defects, water leaks, and janitorial activities. Gypsum board exposed to water should be replaced unless all of the following conditions are met.



  • The source of the water or moisture is identified and eliminated.
  • The water or moisture to which the gypsum board was exposed was uncontaminated1.
  • The gypsum board can be dried thoroughly before mold growth begins (typically 24 to 48 hours depending on environmental conditions).
  • The gypsum board is structurally sound and there is no evidence of rusting fasteners or physical damage that would diminish the physical properties of the gypsum board or system.

CAUTION: When replacing gypsum board in a fire resistance or sound rated system, care must be taken to ensure that all repairs are consistent with the specific fire or sound rated design initially constructed (gypsum board type, fasteners and their spacing, and staggered joints).

These are general recommendations; for more detailed information, a water damage restoration specialist may be contacted. · Adequate ventilation, air circulation, and drying are essential to minimize the potential for mold or other fungal growth.


  • The source of water or moisture must be eliminated.
  • Damaged gypsum board and other wet materials that are to be replaced must be removed from the building to facilitate drying.
  • The interior of the building must be thoroughly dried immediately.
  • The indoor humidity can be lowered by using fans and portable dehumidification equipment and by opening up the 1 Gypsum board that has been exposed to sewage or flood waters must be replaced.

In general, gypsum board should not be exposed to elevated levels of moisture for extended periods. Examples of elevated levels of moisture include, but are not limited to, exposure to rain, condensation, water leakage, and standing water. Some board exposed to these conditions may not need to be replaced, depending upon the source of the moisture and the condition of the gypsum board being considered for replacement. However, IF THERE IS EVER A DOUBT ABOUT WHETHER TO KEEP OR REPLACE GYPSUM BOARD THAT HAS BEEN EXPOSED TO MOISTURE -- REPLACE IT.

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