Exterior Soffit Gypsum Board

Exterior Soffit


Soffit BorderExterior Soffit wallboard is the ideal surface material for sheltered exterior ceiling applications with indirect exposure to the weather. The panel contains a non-combustible gypsum core, enhanced for additional sag resistance with its long edges being tapered, and ends being square-cut and finished smooth. 

Exterior Soffit wallboard is available in: 1/2" panels available with a non-rated treated core, 5/8" Type X treated core for use in fire-rated assemblies. (5/8" Type C treated core on Special Order only)

Gypsum wallboard manufactured by American Gypsum contains no asbestos.

Basic Uses

Exterior Soffit wallboard is intended to provide a sag-resistant product for use in sheltered exterior ceiling applications with indirect exposure to the weather. Commercial uses include marquees, large canopies and covered walkways, open malls, and parking areas. Residential uses include open porches, breezeways, carports, and exterior soffits. The wallboard is secured directly to wood framing or to cross-furring of wood or metal furring channels attached to main supports.

With joints covered, Exterior Soffit wallboard will resist the passage of smoke. For additional information on smoke barriers, refer to Gypsum Association publication, “Building and Inspecting Smoke Barriers” (GA-618).


Exterior Soffit wallboard has achieved UL Environment’s GREENGUARD GOLD Certification. GREENGUARD Certified products are scientifically proven to meet some of the world’s most rigorous, third-party chemical emissions standards, helping reduce indoor air pollution and the risk of chemical exposure while avoiding in the creation of healthier indoor environments.

For more information, visit www.ul.com/gg.

Product Data


Thickness Widths Lengths Edge Types
1/2" (12.7mm) 4' (1219mm) 8' & 12' (2438mm & 3658mm) Tapered
5/8" Type X (15.9mm) 4' (1219mm) 8' - 12' (2438mm - 3658mm) Tapered
5/8" Type C (15.9mm) SPECIAL ORDER 4' (1219mm) 12' (3658mm) Tapered

Special lengths or edges may be available on special order. Consult your American Gypsum sales representative for details.

Technical Data

Storage and Handling

Gypsum board does not generate or support the growth of mold when it is properly transported, stored, handled, installed, and maintained. However, mold spores are present everywhere and when conditions are favorable; mold can grow on practically any surface. GYPSUM BOARD MUST BE KEPT DRY to prevent the growth of mold.

Gypsum board must be stored in an area that protects it from adverse weather conditions, condensation, and other forms of moisture. Job site conditions that can expose gypsum board to water or moisture must be avoided.

Gypsum board must be protected during transit with a weather-tight cover in good condition. Plastic shipping bags are intended to provide protection during transit only and must be promptly removed upon arrival of the load. Failure to remove the shipping bag can increase the likelihood of developing conditions favorable to the growth of mold.

Gypsum board that has visible mold growth must not be used. For additional information, refer to Gypsum Association publication,

"Guidelines for the Prevention of Mold Growth on Gypsum Wallboard" (GA-238). 

Gypsum board must be stored off the ground and under protective cover. Sufficient risers must be used to assure support for the entire length of the wallboard to prevent sagging.

Gypsum board must be delivered to the job site as near to the time it will be used as possible. Individuals delivering gypsum board to jobsites should ensure that it is carried, not dragged, to place of storage/installation to prevent damage to finished edges.

Gypsum board shall always be stacked flat - NEVER on edge or end. Gypsum board stacked on edge or end is unstable and presents a serious hazard should it accidentally topple. Gypsum board should be placed so weight is evenly distributed and the floor is not overloaded.

Applicable Standards


ASTM C 1396 section 8 (C 931)

Federal Specification - None



ASTM C 840

Gypsum Association GA-216

Surface Burning Characteristics


Flame Spread 0

Smoke Developed 0

Fire Resistance Ratings


LEED Contributions

Our products can contribute to the following credits within the Materials and Resources (MR) category.

  • LEED MR Credit 2: Construction Waste Management
  • LEED MR Credit 4: Recycled Content
  • LEED MR Credit 5: Regional Materials

Our products can contribute to the following credit within the Indoor Environmental Quality (IEQ) category.

  • LEED IEQ Credit 4.6: Low-Emitting Materials - Ceiling and Wall Systems (SCHOOLS ONLY)

To learn more please click the LEED link at right.