Portland cement boards are used under tile and are stronger than typical gypsum board.

• A. For exterior cladding
• B. Used for ceilings
• C. Used instead of gypsum board
• D. Used under tile, stronger than typ gyp

Answer: (D)

Tile installations require a substrate that stays rigid, stable in moisture, and strong enough to support tile weight. Portland cement boards are designed as tile backer substrates: their cementitious makeup resists water and won’t swell or warp, so heavy or textured tile stays securely in place. Gypsum board, by contrast, absorbs moisture, weakens in damp conditions, and can crumble or allow adhesive failure, making it unsuitable for use under tile in wet areas. That’s why the best choice is cement boards under tile and why they’re described as stronger than typical gypsum board. The other options don’t fit because exterior cladding or ceilings involve different substrate needs, and using cement board instead of gypsum board isn’t a general replacement for dry interior walls—it's specifically about providing a moisture-resistant, rigid base under tile.