Gypsum board has been used extensively over the last 50 years as the interior wall surface material of choice. Gypsum board typically consists of a layer of gypsum with a layer of special paper on each face. It is inexpensive, easily installed, and accommodates a wide range of surface treatments, including paints and wall coverings. There are several types of gypsum board to meet the demands of the industry. Fire resistant gypsum board, Type-X, is used where a fire-rated wall is required. The thickness of the panels, number used, and seaming determine the number of hours of fire separation achieved.

Mold and mildew growth have become significant problems in modern construction. Building codes have required increased insulation combined with vapor and air infiltration barriers, creating ‘tight’ buildings where air movement through walls has been eliminated. The result often is that often moist air is trapped within wall cavities. This environment is perfect for the growth of mold and mildew.

In recent years the gypsum board industry has responded to the need for a gypsum board product that will not support the growth of mold or mildew. The presence of a paper face provides a source of food for mold and mildew growth if the paper becomes wet and remains damp. Several manufacturers have developed a new group of panels with paper faces treated with chemicals that inhibit the growth of mold. This approach, combined with careful design to avoid trapped air spaces, can prevent mold growth for a number of years.

Georgia-Pacific developed gypsum products that have no paper face. The absence of a food source for mold reduces the chance for mold growth. Paperless gypsum board consists of a gypsum core sandwiched between two layers of fiberglass mesh. The fiberglass is naturally resistant to mold growth. This product is installed in the same manner as standard gypsum board. To provide a smooth paintable surface it is recommended that the entire surface be coated with a skim coat of gypsum compound (Level 5 Finish).