Shower finished surface height above drain inlet must be at least how many inches?

Shower finished surface height above drain inlet must be at least how many inches?

• A. 72 inches
• B. 70 inches
• C. 80 inches
• D. 76 inches

Answer: (A)

The key idea is that drainage depends on gravity, so the finished shower surface must sit high enough above the drain inlet to allow the water to flow toward the drain with a proper slope and to accommodate the shower pan assembly (liner, mortar bed, tile) without crowding or losing that slope. A minimum of 72 inches provides enough vertical space for the pan components and tile thickness while preserving the intended slope from the walls toward the drain, preventing water from pooling near the drain. If the finished surface were lower, you could end up with inadequate slope and standing water, which can cause drainage problems and water damage. The 72-inch minimum is used because it reliably ensures the necessary clearance for proper drainage geometry and installation.

The key idea is that drainage depends on gravity, so the finished shower surface must sit high enough above the drain inlet to allow the water to flow toward the drain with a proper slope and to accommodate the shower pan assembly (liner, mortar bed, tile) without crowding or losing that slope. A minimum of 72 inches provides enough vertical space for the pan components and tile thickness while preserving the intended slope from the walls toward the drain, preventing water from pooling near the drain. If the finished surface were lower, you could end up with inadequate slope and standing water, which can cause drainage problems and water damage. The 72-inch minimum is used because it reliably ensures the necessary clearance for proper drainage geometry and installation.