Mold Control On The Job Site

Molds are naturally occurring substances that are found everywhere. Excessive mold growth can be detrimental to a building or its inhabitants. Some molds can deteriorate woods or other organic materials, while other molds may cause or contribute to adverse health effects.

Mold grows in conditions of moisture, darkness, and stagnant air. Molds need moisture to grow and reproduce. Mold growth results in the release of millions of spores that may be inhaled by inhabitants. Moisture control is the critical step for controlling mold growth. Moisture control in buildings requires cooperation between building owners, designers, contractors, and occupants.

Contractors can affect the presence of building moisture during construction. A contractor may allow sources of moisture to affect the materials and structure during the operation and management of the job site. Contractors that use poor workmanship may also negate design features that are intended to control moisture. This handout highlights steps that can be taken by a construction contractor to minimize conditions that promote mold growth.

Site Management

• Inspect all shipments of construction materials for visible mold growth or excessive moisture.
• Do not unload lumber or other moisture-sensitive materials in the rain, unless protected from exposure.
• Schedule deliveries to minimize the amount of time moisture-sensitive materials are stored on site.
• Store materials off the ground and away from sources of moisture.
• Loosely cover materials with plastic sheets or tarps to protect the materials from rain or snow.
• Anchor material covering from the top and keep the cover materials away from the sides and bottoms to promote air circulation and decrease moisture retention.

Construction Practices

• Protect building interiors from prolonged rain and snow exposures.
• In the event framing lumber has been exposed to heavy rain or snow, allow it to dry out before closing the structure.
• Provide ventilation to remove moisture from buildings during construction.
• Clean and treat visible mold growth before wood products are sealed.
• Check building water services for leaks and improper installation.
• Provide proper ventilation in attic and crawl spaces.
• Ensure that all stove vents, dryer vents, and other spot ventilation exhaust to the outside.
• Ensure that all building penetrations, intersections, and openings are properly flashed to prevent leaks.
• Ensure that building sealants are compatible with adjacent building materials.
• Seal any tears, openings, or punctures that are found in vapor diffusion retarders and air barriers before covering with other materials.
• Drain downspouts away from the foundation.
• Ensure that the building's siding is not in contact with ground surfaces.
  

XL Environmental • Risk Control Division • 520 Eagleview Boulevard, PO Box 636, Exton, PA 19341 • Phone: 800-327-1414 • Fax: 610-458-7285 • xlenvironmental.com

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