What is the recommended slope for a shower floor and why?

• A. Approximately 1/4 inch per foot toward the drain to ensure proper drainage
• B. 1/8 inch per foot away from the drain
• C. 1/2 inch per foot toward the drain
• D. Flat floor with no slope

Answer: (B)

Water on a shower floor should be directed toward the drain with a gentle, consistent slope so water doesn’t pool and can reliably reach the drain. The standard guideline is roughly 1/4 inch of drop per foot (about a 2% slope) toward the drain. This gradient is enough to overcome surface tension and tile texture, ensuring water flows smoothly into the drain and through the waterproofing layer. If the slope is too shallow, standing water can remain, promoting slip hazards and mold growth. If it’s too steep, it can cause uneven tile joints and potential damage or splashing beyond the shower area. A flat floor won’t drain at all. Slope away from the drain would push water away instead of toward it, defeating the purpose of the shower floor design.