Which type of drywall would be required above a bath tub?

• A. M.R. D.W.
• B. Type X
• C. Gypsum Board
• D. Green Board

Answer: (A)

Moisture exposure is the key factor in this location. Above a bathtub, drywall will encounter steam, humidity, and occasional splashes, so you want a material that resists moisture. Moisture-resistant drywall is designed to limit water absorption and stay stable in wet conditions, helping prevent warping, deterioration, and mold growth over time.

Type X is about fire resistance, not moisture, so it doesn’t address the bathroom’s moisture needs. Regular gypsum board soaks up moisture and can deteriorate in a wet area. Green board is moisture resistant but not waterproof; in a tub/shower zone it can still fail with direct water contact or high humidity. Therefore, moisture-resistant drywall is the best choice for above a bathtub.