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ORF Home > Technical Resources > Policies and Rules > Instructions for Remediating Moisture in the First 48 hours to Prevent Mold Growth

Instructions for Remediating Moisture in the First 48 hours to Prevent Mold Growth

In the event of water infiltration into building areas, the first 24 to 48 hours are critical in prevention of mold growth.

Identify the source of the moisture: Following the discovery of water infiltration into building spaces, the first step is to identify whether the moisture source is clean or polluted water.

    • If the water infiltrating the building is clean (no chemical or biological pollutants or sewage), the sooner repair, clean up, and drying are accomplished, the greater the chances of preventing mold growth.
    • If existing mold growth is found or if the water is polluted, contact the ORS Division of Occupational Health and Safety (DOHS) at 301-496-3353 and review the information in Moisture Infiltration after 48 Hours.
    • Potable, de-ionized (DI), reverse osmosis (RO), and distilled water are considered unpolluted unless they have come in contact with a pollution source. All others are considered polluted.

Halt further moisture infiltration: The next step is to halt further moisture intrusion by repairing the defect and conduct an inventory of the water damaged areas, building materials, and furnishings, paying special attention to identifying wet carpet under cabinets, furniture, and furnishings. If it is impossible to determine how long the water infiltration has existed, it should be handled as if it has existed for more than 48 hours.

Determining whether materials are “dry” sometimes requires a judgment call. When in doubt, you should use a moisture meter to check drywall in an affected area and compare the reading to a control reading in a non-affected area. Readings should be the same.

Specific instructions: Following are guidelines for preventing mold growth on specific water-damaged materials.

  • Ceiling Tiles: Discard and replace. If the tiles are glued onto the ceiling or wall, call DOHS (301-496-3353) so they can analyze samples to determine whether the material(s) contain asbestos.
  • Carpet and Backing: Remove all furniture/cabinets sitting on wet carpet. Remove water with a water extraction vacuum; reduce ambient humidity levels with de-humidifiers; and speed dry by using fans.
  • Cellulose Insulation: Discard and replace.
  • Fiberglass Insulation: Discard and replace.
  • Electrical: Consider all wet wiring, light fixtures, and electrical outlets to be shock hazards. Turn power off in the area until these have been checked by a building inspector or electrician. All electrical circuit breakers, GFI’s, and fuses that became wet need to be replaced. All electric motors, light fixtures, and so on that were wet must be opened, cleaned, and air-dried by a qualified person. They must then be inspected to make sure there is no visible moisture in them before they are placed back into service.
  • Books and Papers: Non-valuable materials should be discarded. Photocopy valuable/important items and discard originals. For items with high monetary or sentimental value, consult with a restoration/water damage specialist.
  • Concrete or Cinder Block Surfaces: Remove water with a water extraction vacuum. Speed dry them with de-humidifiers, fans, and/or heaters.
  • Hard Surfaces, Porous Flooring (Linoleum, Ceramic Tile, Vinyl): Vacuum or damp wipe with water and mild detergent and allow them to dry. Check under flooring to make sure it is dry.
  • Non-Porous, Hard Surfaces (Plastics, Metals): Vacuum or damp wipe with water and mild detergent and allow to dry.
  • Upholstered Furniture: Remove water with an extraction vacuum. Accelerate drying with de-humidifiers, fans, and/or heaters. Drying furniture may be difficult to complete within 48 hours. If any of the furniture is valuable, consult a restoration/water damage specialist.
  • Wallboard (Drywall and Gypsum Board): May be dried in place if there is no water stain and/or obvious swelling and the seams are intact. Remove base molding to inspect the wallboard. If the wallboard cannot be dried within 48 hours, measure twelve (12) inches above the water mark/damage and remove and discard wallboard below that point. Remove and discard damp insulation, and ventilate the wall cavity. In some cases it may be difficult to tell if the wallboard has been sufficiently dried. A moisture meter can be used to check for moisture. To use a moisture meter, check the affected area and compare the reading to a control reading in a non-affected area.
  • Wood Surfaces: Remove moisture immediately and use de-humidifiers, gentle heat, and fans for drying. Use caution when applying heat to hardwood floors. Treated or finished wood surfaces may be cleaned with mild detergent and clean water and allowed to dry. Wet paneling should be pried away from the wall for drying.

This page was last updated on Nov 27, 2012