Product Description

Cabot Moisture Resistant Gypsum Board consists of a water resistant core of noncombustible gypsum rock sandwiched between a green, water-resistant face paper and a water-resistant brown-back paper. Both front and back paper are made from 100% recycled paper. The face paper is formed along each edge, wrapped around, tapered and sealed to the back paper. This produces a strong yet flexible panel which meets most commercial/residential construction requirements for wall and ceiling substrates. Even though Cabot Moisture Resistant Core is a limited-combustible product with a Class A Flame Spread Rating it is not used in an assembly requiring a fire rating. 

The panel is designed to be used in high moisture areas such as bathrooms, kitchens, and laundry rooms. The board comes from the factory as a ready-to-finish product. After installation, the ends, edges, corners and fastener heads can be concealed with joint treatment systems to produce a smooth seamless surface prior to final decoration. The panel can also be used as a base for ceramic tile, or laminate panels. It should however not be used behind a finish that comes in direct exposure to running water or continuous high humidity.


Production Specification

Cabot Water Resistant Core Gypsum Board is manufactured to meet or exceed the requirements of ASTM C1396 and CAN/CSA A82.27 and Installation Standards ASTM C840.


Product Limitations

  1. Exposure to extreme temperature 52o C (125o F) should be avoided. 
  2. Store indoors and off ground surface. 
  3. Boards should be stacked flat with care taken to prevent sagging or damage to edges, ends and surfaces. 
  4. Ceiling framing should be no greater than 12" o.c. for 1/2" and 16" o.c. for 5/8", 24" for walls. 
  5. Should not be used as a tile backer in tub and shower surrounds or in areas subject to constant high humidity i.e. food processing areas or gang showers.
  6. In areas to be finished with ceramic tile, the board should not have a vapor barrier applied behind it. 
  7. For interior use only.


Product Data

Surface Burning Characteristics: Flame Spread Rating of 15 Smoke Developed 0 as per ASTM E 84 or CAN/ULS-S102.

Thickness: 1/2" (12.7 mm) and 5/8" (19 mm)

Width: 4' (1220 mm)

Lengths: 8' (2440 mm)

Edges: Tapered

Packaging: Two pieces per bundle, face-to-face and end taped. Special lengths may be available on special order, consult nearest Cabot Gypsum sales office.


Product Application

Cabot Moisture Resistant Gypsum Board can be applied only when the building temperature can be maintained not less than 10oC (50o F) and no more than 35C (95o F) in any given room or area. Adequate ventilation must be maintained during installation and finishing and curing process.



Cabot Moisture Resistant Gypsum Board is designed to accept most types of paints, texture and wall covering materials. The surface should be primed and sealed with a full bodied quality latex primer before applying a decorative material. If glossy paints are used in areas such as kitchens or bathrooms, a Level 5 finish is recommended to reduce highlighting or joint photographing. Joint treatment must be thoroughly dry before proceeding with primer-sealer application and final decoration. Do not apply drywall joint compound to joints or fasteners that are to be tiled.


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