MMR Gyp is best described as

• A. Mold & moisture resistant, used at restrooms, not for wet walls - at wet walls, portland cement boards are needed
• B. Type X Gyp
• C. Used only for exterior walls
• D. A cement board

Answer: (A)

MMR Gyp refers to mold‑resistant gypsum board. It’s designed to resist mold growth in typical humid interior spaces, such as bathrooms, and handles humidity better than standard gypsum board. However, it is not waterproof and should not be used where there is direct, continuous water contact or “wet walls.” For those areas, cement boards (like Portland cement boards) are required because their cementitious core is far more resistant to water damage.

This differs from Type X gypsum board, which is about fire resistance rather than moisture performance, so it wouldn’t be the best choice for mold resistance. Gypsum board is generally used for interior walls, while exterior walls require different materials, and cement boards are used in wet or damp environments.