Why Controlling Moisture Before, During and After Construction Matters


It is a well-known fact that moisture and mold have the potential to cause significant issues throughout the building lifecycle (from manufacturing to design, distribution to construction, and even maintenance). Moisture is critical because it must be present for mold to develop and grow. Since mold occurs naturally everywhere in our environment, it is important to know how construction practices can influence moisture management. 

Let’s take a look at the impact of moisture and potential for resulting mold during the construction cycle, how to control moisture, and finally product selection and resulting performance under these circumstances.  

Controlling Moisture Controls Mold

Architects, designers, contractors and maintenance engineers must all work together to prevent mold growth during construction and throughout a building’s lifecycle. Controlling mold requires careful design, proper construction and thorough maintenance—all of which aim to manage moisture, which is the only variable that can be controlled within the construction environment. 

The risk for mold development is elevated by:

  • Storage conditions of materials
  • Faster track schedules
  • Poor execution of details for water control 
  • Energy efficient buildings have greater moisture sensitivity
  • Lack of protection from snow and rain during the construction phase
  • Inadequate drying of concrete, plaster and paint as a building is completed
  • Roof and pipe leaks
  • Gross water penetration of the façade
  • Natural disasters

A systems approach to managing water is the most effective strategy for controlling moisture and minimizing the growth of mold. 

How to Manage the Risk of Mold Development

To control the accumulation of moisture, careful design, good construction practices and proper maintenance are key. However, another critical component that reduces the risk of mold growth is specifying and installing moisture- and mold-resistant products that have been tested to ASTM D3273, Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber. Moisture- and mold-resistant gypsum panels and glass-mat gypsum panels are two excellent examples of such products. 

Below are several additional ways to effectively reduce the risk of mold growth: 

When the risk of moisture exposure is present, be sure to choose products and systems that offer adequate resistance. For example, standard gypsum products must be protected from elements before, during and after construction, and therefore are not suitable in moisture-exposed applications. However, USG offers a comprehensive product line, application guidelines and tools to address wet area performance issues. Our high-performing products are engineered for one or all of the following: 

  • Moisture resistance
  • Sag resistance
  • Mold resistance
  • Tile bond

It’s also important to note that moisture- and mold-resistant products are effective only when used in conjunction with sound design and construction practices.

Specifying and installing moisture- and mold-resistant products is a critical component of sound construction practices, as they act as extra protection against mold growth when incidental moisture (condensation, steam or dampness) is present. For example, in areas with limited moisture exposure, paper-faced wallboard featuring Mold Tough® technology is recommended. One such example is USG Sheetrock® Brand UltraLight Panels Mold Tough® (Regular and Firecode® X). While these panels will protect against incidental wetting and the resulting mold growth, they must still be protected from elements before, during and after construction. 

For areas where extended moisture exposure is present, such as pre dry-in construction (also known as top-down or fast-track), specifying and installing panels that  feature an inorganic water-shedding glass-mat enclosure and noncombustible gypsum core that’s treated to achieve the highest level of moisture- and mold-resistance available are the ideal solution. One such example is USG Sheetrock® Brand Glass-Mat Panels Mold Tough® (Regular and Firecode® X).

For your next build, be sure to refer to USG literature for more information on the most effective moisture and mold mitigation strategies: